CA1063930A - Subterranean mining apparatus and method - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Method and apparatus for subterranean slurry drilling and mining of granular ore, such as phosphates, with a combined drilling and mining apparatus. The apparatus includes a tool string having a drilling head and mining head that are selectively interchangeable on its upper end for drilling into one or more ore strata to be mined and thereafter to remo? ore from the strata as a slurry. The drill string includes a plurality of inner and outer pipe sections connected to a mining nozzle section, to an eductor pump section, and to a drill bit at its lower end. A drilling/mining liquid is directed through the tool string during both the drilling and mining modes of operation. During drilling, liquid is directed through a foot valve into the rotating bit to wash cuttings to the surface externally of the tool.
During mining, the tool string is rotated, the foot valve is closed, and a mining nozzle is opened thereby causing liquid jetting form the mining nozzle to reduce the ore to a slurry. The slurry is pumped to the surface by liquid passing upwardly through the eductor pump and through the inner conduit. Without removing the apparatus from the hole, a hydraulic control system is actuated by hydraulic pressure equal to or less than system pressure for shifting the mining nozzle, the eductor nozzle, and the drill bit foot valve between a drilling mode and a mining mode thus enabling several different ore bearing strata to be mined.
In a modified from of the invention a plurality of vertically spaced mining nozzles are provided and each -1a-nozzle is aligned with a different ore strata. A hydraulic control system is provided for controlling the hydraulic components between their drilling and mining modes, and for opening and closing the mining nozzle independently of each other. The control system is responsive to pressure equal to or less than the system pressure.

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Description

106393~
CROSS REFERENCE TO RELATED APPLICATION
My copending United States Patent Application Serial No. 704,278, filed on even date herewith and assigned to the assignee of the present invention, dis-closes additional modified forms of the present invention.
My copending application issued on ~ovember 22, 1977 as United States Patent No. 4,059,166.
: BACKGROUND OF THE INVENl'ION
Field of the Invention This invention pertains to improvement in subterranean slurry mining and more particularly relates to a method and apparatus for drilling and mining one or more layers of granular ore, such as phosphates, without withdrawing the mining apparatus from the hole between the drilling and mining modes of operation.
. Description of the Prior Art Subterranean slurry mining of phosphates or the like is broadly known in the art as evidenced by : United States Wenneborg et al patents 3,730,592 and 3,747,696 which iss~-e d on May 1, 1973 and July 24, 1973, respectively, and are assigned to the assignee of the present invention.
The modified embodiment of the device disclosed in Wenneborg et al 3,.747,696 is the most pertinent prior art embodiment and comprises a combination slurry drilling ~-and mining apparatus which may be changed between its drilling mode of operation and its mining mode of opera-tion to mine several different layers of ore without ; r~quiring that the apparatus be pulled out of the hole " ~ .

, . . .

or well. However, the hydraulic control system or changing the several valves from the drilling moae to the :- mining mode require~ a positive pressure of about 2000 psig in the prior art device which is much greater th~n the appro~imately 1000 psig mining pressure~ The prior art hydraulic control system thus requires additional high pressure pumping equipment, and is also subject to damage due to the very high control pressures and "water hammer" ~ype force~ which may be applied to the system.
Wenneborg et al 3,730,592 discloses a method which contemplate-~ the use of surface controllea pre~sure~ -egual to or in excess of the drilling pressure ~or shiftin~
: ~he mining nozzle, the eductor nozzle,and the drill bit foot valve between the ~rilling mode and the mining . 15 mode. In addition, the patentee discloses the use of control pressures which lie in a range between the drilling press~re and the minng pressure for modulating the mining nozzle. Modulation of the mining nozzle is effeetive to .
- control the cavity pressure, and also the liquid level in the minea ca~ity to vary the mining conditions for the particular s~ata being mined.
~nited States parent and aivisional pa~ent Nos. 3,1~,177 and 3,316,985 which issued to A.B. Fly on No~ember 3, 1964 and May 2, 1967, respecti~ely, dis-

2~ close a method and apparatus fox under-reaming or slurry mininy a well and can also be con~rolled to alternately bore aeeper and mine other strata in the well after the ~irst boring and mining opexations have been completed.
Valves operated by electric motors located within the tool stxing convert the apparatus from a drilling operation ( to a mining op~tion. The amount of force that can be applied to convert the apparatus from the drilling opera-tion to the muning opera~on is, accordingly, limited by the size of the electric motors that can fit within the tool string.
SUMM~RY OF THE INVE~TIO~
In accordance with a firs~ embodimen~ of the present invention a combined drilling and mining apparatus, ` and method for operating the same, is provided. The 10 ` combined appaEtus comprises a double condu`It tool string having a drill bit on its lower end, an eductor pump ~ection and a mining nozzle section both of which are disposed within an ore bearing strata upon ~ompletion o~
the initial drilling operation, and a mining head con-15` nected through a swivel joint at the upper end of the toolstring.
During drilling, a mining/drilling liquid (here-inafter referred to as water) is directed at about 30~ -psig ~sur~ace pressure) in~o a drilling head attached to 20 a conventional vertically movable and rotatably driven `
~ower swivel. The water is directed through the outer --annular conduit of the tool string and then passes ~hrough a ~ool ~it foot valve into the tool bit. The wat~r aids ~he drilling process and flushes the cuttings upwardly to ~5 the surface through the annular passage defined between the outer surface of the rotating tool string and the inner 3urface of the uncased drilled hole or well~ -After the initial drilling h~s been completed, a mining head replaces the drilling heaa on ~he upper end o~ the pipe string and i5 connected thereto thn~ugh a 10ti3930 swivel joint to allow rotation of the tool s~ring duri~g mining. The mining head includes an inlet passase which enables the drilling/mining water to flow downwardly in the outer annular conduit of the tool string, and to ~llo-,t a slurry of wat~r and the granular ore being mined to flow upwardly through a generally cylindrical inner conduit in the tool string and out through a slurry outlet passage in the mining head for collection in an~ suitable collect-ing means such as a tank or pipeline to a processi~g plant.
A hydraulic control system is selectively controlled ~rom the surface to maintai~ the drill bit foot ~alve open, the eductor pump nozzle closed and the mining noæzle closed during the drilling mode of ~eratio~; and to maintain the drill bit foot valve substantially closed, the ~uctor nozzle open, and the mining nozzle open during the mining mode of operation. An important feature of the invention is that the system pressure of the hydraulic control system a~ the drilling pressure are substantially the same (i.e., a~out 300 psig) during the drilling mode 20 *hu5 providing substantially no aifferential pressure in the two systems during drilling. During the mining de the mining pressure is about 700-1000 psig surface pressure and ~he control pressure is vented to the atmosphere and accordingly, i~ at substantially 0 psig whe~ it is desired to maintain the mining nozzle and ~he educ~or hozæle fully open and maintain the drill bit foot valve substantially closed. The mining nozzle and eductor nozzle are both spring urged toward the closed position. The spring force acting on the eductor nozzle is such that a supply or start-up system pressure of about 60 psig will overcome the spring force causing the eductor nozzle to open and the foot valve to close. since the cavity pressure below the closed foot valve is low, the system pressure acting on the large upper surface of the foot valve holds the fcot valve closed (and the eductor nozzle open) even if the control pressure and system pressure are both increased to mining pressure. A start up pressure of akout 100 psig will overcome the spring ~orce controlling the mining nozzle and will cause the mining nozzle to open. If de-sired the mining nozzle may be closed during mining by applying mining pressure to the control system.
After the granular ore has been depleted from the mined matrix, the mining head is removed and the associated cprings open the foot valve and close the mining and eductor nozzles thus returnin~ the apparatus to its dr~ling mode. The hole or well cavity may the~ be drilied deeper, and additional pipe sections are then assembled in the tool string until the mining nozzle an~
slurry inlet are located in another ore matrix at which time the mining head is replaced and the control system is bled to return the nozzle plugs and foot valve to ~heir -~
mining positions. The new matrix is then mine~ ana there-after additional matrixes at different levels may be minea by alternately drilling aeeper and mininy the ore bearing matrixes disposed opposite the minin~ nozzle and eductor pump inlet at the different levels. It is also understood that the tool may fixst be drilled down to its lowest level, and can then alternately be raised to higher levels as it mines the several ore bearing matrixes.
In a second embodiment o~ the invention a plurality ` ~063930 o~ mining nozzles are assembled in the tool stri~g ard are vertically spaced apart distances equal to the spacing o~
à plur~ity o~ ore bearing matrixes desired to be mined.
With this embodiment of the invention, a plurality of S levels, or example two levels, may be mined without changing the elevation of the mining apparatus or requiring that the apparatus be changed from its mini~g mode to its drilling mode and back to its mining mode in order to mine ` the two levels. In a system hàving two mining ~ozzle-~, the lower matrix may be mined first so that ors frDm the - upper matrix, which is separated from ~he lower ma~rix by a layer o~ overburden, will partially collapse into the lower matrix and will be drawn through the slurry inlet o~
the aductor pump at the lower level.
The two mining nozzle sys~em is especially advantageous when mining an upper ore matrix ~hich incluaes - cons;derahle clay mixed with the ore ana accoxdingly is d~ficult to reduce to a slurry; and a lower matri~ which includes ~ess clay and accordingly is more easily reduced to a slurry. In this example, the upper mining zzle may be smaller than the lower mining nozzle so that the division of water during mining between the upper mining nozzle and the eductor nozzle is such that the water passing through - the eductor nozzle will lower or "draw dow~" the water level in the upper matrix below the jet of ~ater passing through the small capacity upper nozzle. Thus, the jet from the upper nozzle passes through air, not water, and therefore more effectively reduces the ore to a slurr~. The lower mining nozzle may have a much larger flow capacity and accordingly provide less watex to the eductor nozzle result-ing in a lower pumping capacity. Thus, the cavities from which ore has been removed may be completely filled with water thereby preventing collapse of the upper walls of the cavity, or rupture of the floor of the cavity due to underground water pressure. If the area being mined has high subterranean water pressures as indicated in the above example, it is preferable that the upper strata be mined before the lower strata.
A modified hydraulic control system is provided for the apparatus having two or more mining nozzles therein, but operates in the same manner and with substantially the same control pressures used in the first embodiment. The modified control system includes additional valve means which will cause a selected one of the mining nozzles to be opened during mining while the other mining nozzle (or nozzles) are closed.
Another modified control system is provided which ;
is self-activated by detecting the pressure differential between the system pressure and the pressure in the well - 20 cavity for selecti~ely opening and closing the nozzle without the aid of control lines to the surface.
In accordance with the present invention a method of drilling a hole into and mining ore from a subterranean deposit of granular ore using apparatus including a multi-section tool string having a drill bit on its lower end;and a mining nozzle and a foot valve intermediate the ends of the tool string with each being movable between a dril-ling mode and a mining mode of operation is provided, the method comprises the steps of: alternately rotating and holding the outer portion of a multi-section tool string - from rotation for screwing the outer portions together while assembling the string section-by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial 5 quantity of liquid during the drilling mode at system pre~-sure through the foot valve into the hole for washing cut-tings to the surface, closing the foot valve and opening the mining nozzle during the mining mode for terminating the major quantity of liquid flow into the bottom of the hole, directing a high pressure stream of liquid trans-versely of the tool string through the mining nozzle into the ore matrix to reduce the ore to a slurry, rotating the tool string during mining, and selectively controlling the opening and closing of the mining nozzle and foot valve while the tool string is in the hole by applying a control pressure equal to the system pxessure during drilling for :~ maintaining the mining nozzle closed and the foot valve open, and by applying a control pressure less than the system pressure during mining for opening the mining -~
nozzle and closing the foot valve.
Also in accordance with the present invention a method of drilling a hole into and mining ore reduced to a ~-- slurry from a subterranean deposit of granular ore using - apparatus including a multi-section tool string having a drill bit on its lower end; and an eductor nozzle, a mining nozzle, and foot valve intermediate the ends of the tool string with each being movable between a drilling mode and a mining mode of operation is provided, the method compris-ing the steps of: alternately rotating and holding the outer portion of a multi-section tool string from rotation for ~063930 screwing the outer portions together while assembling the string section-by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial quantity of liquid during the drilling mode at system pres~ure through the foot valve into the hole for washing cuttings to the surface, clo~ing the foot valve and opening the eductor nozzle and mi~ning nozzle during the mining mode for terminating the major quantity of liquid flow into the bottom of the hole, directing a fIow of liquid upwardly through the eductor nozzle to pump the slurry to the surface, direc~ing a high pressure stream of liquid transversely o the tool -string through the mining nozzle into the ore matrix to reduce the ore to a slurry, rotating the tool string during mining, and selectively controlling the opening and closing of the eductor nozzle, mining nozzle and foot valve while the tool string is in the hole by applying a control pres-:: sure equal to the system pressure during drilling for maintaining the eductor nozzle and mining nozzle closed and the foot valve open, and by applying a control pressure less than the system pressure during mining for opening the -~
eductor nozzle and mining nozzle and closing the foot valve.
Further in accordance with the present invention a method - of drilling a hole into and mining ore from a subterranean . 25 deposit of granular ore using apparatus including a multi-. section tool string having a drill bit on its lower end;
and a mining nozzle, an eductor nozzle and a foot valve intermediate the ends of the tool string, each being mova~le between a drilling mode and a mining mode of operation is provided, the method comprising the steps of: alternately ~ ~9;~ .

rotating and holding the outer portion of a multi-~ection tool string from rotation for screwing the outer portions together while assembling the string section-by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial quantity of liquid during the drilling mode at system pressure through the foot valve into the hole for washing cuttings to the surface, closing the foot valve and opening the mining nozzle and eductor nozzle during the mining mode for terminating the major quantity of liquid ~bw into the bottom of the hole, splitting the liquid flow with a portion of the liguid being directed as a high pressure stream trans-versely of the tool string through the mining nozzle into the ore matrix to reduce the ore to a slurry and with an-other portion of the liquid directed upwardly through the - -- eductor nozzle to pump the slurr~ to the surface, rotating the tool string during mining, and selectively controlling the opening and closing of the nozzles and foot valve while the tool string is in the hole by appl~ing a control pres- ~ -sure equal to the system pressure during drilling for maintaining the mining nozzle and eductor nozzle closed and the foot valve open, and by applying a control pres-sure less than the system pressure during mining for opening the m~ning nozzle and eductor nozzle and closing thè foot valve.
BRIEF DESCRIPTION OF THE DR~WI~GS
Figure 1 is a diagrammatic elevation of one embodiment of the drilling and mining apparatus of the present invention shown supported from a barge and illus-trated in its mining mode in a multi-stratum ore bed with ~" , -9a . ~-:

one level being mined, several section~ of the tool string being cut away to greatly foreshorten the height of the Figure.
Figure 2 is a diagrammatic vertical central section taken at a larger scale illustrating the several components of the tool string at a larger scale, several sections of the tool string being cut away to reduce its illustrated height.
Figure 3 i9 a top plan view illustrating a mechanism for supporting the torque wrench while allowing - a small amount of relative movement between the barge and the tool string.
Figure 4 is a section taken along lines 4-4 of ., -9b-.

i063930 Figure 3.
E~igure 5 is a vertical secti~n taXen through a drilling head which is screwed into the upper end o~ each pipe section, in turn, as the well is being drilled; and is thereafter screwed into the top of the mining head for supporting the apparatus during mining, said vie~ further illustrating the details of the upper end o~ standard pipe ` sections-of the tool string.
Figure 6 is an enlarged vertical central section taken through the mining head of the apparatus o~ FiguxeR
1 and 2 illustrating its specific details of con truction.
Figure 6A is an enlarged sectional view o~ a portion o~ a pipe section joint illustrating stxucture for centering the inner and outer pipe strings and ~or coupling the control lines.
Figure 7 is an enlarged vertical section taken ! along lines 7-7 o~ Figure 9 through the mining nozzle section of FigureS 1 and 2 with the mining noæzle plug being shown in the open mining position, certain parts --~eing cut away.
~igure 8 is an elevation with parts in section taken generally along lines 8-8 o~ Figure 7~ :
Figure 9 is a top plan o~ the apparatus illus-trated in Figure 7, certain parts being cut away.
Figure 10 is a horizontal section taken along lines 10-10 o~ Figure 7.
Figure 11 is a bottom view o~ the mining nozzle section illustrated in Figure 7 prior to being screwed in~o the next lower section which is the eductor section, a portion of one control line being cut away.

, ( !

Figure 12 is an enlarged vertical section taken along lines 12-12 of Figure 13 of the ~uctor pump section shown coupled to an upper pipe section and to the drill bit with the parts in their drilling mode; the central portion of the venturi area of the pump being cut away to foE~horten the view, and a fragment of one of the control lines being shown out of its normal position in phantom ` lines.
Figure 13 is a plan of the eductor pump section, taken without the upper pipe section illustrating structure for centering and locking the upper portion o~ the inner pipe string from rotation relative to the upper portion of the string.
Figure 14 is a horizontal section taken along -lines 14-14 of Figure 12 illustrating the structure ~or separating the water and slurry flow passages and also illustrating the guard for the mining flow inlet.
Figure 15 is a horizontal section taken along tines 15-1~ o~ Figure ~ illustrating certain conduit connections for sensor/control lines used for controlling the operation of an eductor nozzle, the drill bit foot valve, ana a mining nozzle.
Figure 16 is an enlargea vertical section taken along lines 16-16 of Figure 13 showing the eductor nozzle and foot ~alve positioned in their mining mode~
` Figure 17 is a horizontal section taken at the plane indicated by lines 17-17 of Figuré 2, illustrating an alternate ratchet drive for rotating the tool string during mining.
~igure 18 is a section taken along lines 18-18 of Figure 17 transversely of the barge.
~ igure 19 is a schematic diagram illustrating a hydraulic circuit which includes control lines leading to the surface for controlling the opening and closing of the ~ining nozzle, the eductor nozzle, and the foot valve and also for detecting the cavity pressure.
Figure 20 is a schematic diagram illustratins a modified control circuit which actuate~ the nozzles in accordance with variations of system pressure and without the aia of control lines to the surface.
Figure 21 is a diagrammatic vertical centra}
section taken through a second embodiment of the in~ention which is substantially the same as that disclosed in Figure 2 except two mining nozzles are illustrated~
Figure 22 is a schematic diagram similar to Eigure 19 ~ for controlling the operation of the apparatus of Figure 21.
:! DESCRIPTXON OF THE P~EFERRED EMBODrMENT
The subterranean slurry drilling and muning - apparatus 30 (Fig. 1) of the present invention is supportea on a mobile vehicle such as a bar~e 32 floating in a pon~
34 over the mining site. Conventional components o~ a wéll - drilling rig 35 on the ~arge are employe~ auring ~he arll-ling mode of operation to assemble the mining and drilling apparatus 3~ section-~-section. Prior to dxillLng the rig 35 is used to drive a large diameter conductor pipe 37 into the floor of the pond 34 to prevent the water in the pond from flowing into the well cavity.
The apparatus is then operated in its mining mode to remove and collect a slurry of liquid and ore from the matrix being mined. After the reclaimable granular ore has been mined from one or more ore matrixes at the mining site, the apparatus is pulled from the well and is dis-assembled enabling the barge to move to anot~er site.
Although the apparatus 30 is primarily intended for use in mining phosphates from one or more ore strata at depths between about 200 and 300 feet below the surface, it will be understood that the apparatus may be used at other depths for mining other types of ore including non-metallic material. It will also be understood that the t`erm "ore" as used herein include9 gravel, rocks, or any other solids that the apparatus i9 capable of slurry pumping to the surface. It will also be understood that .
the apparatus is capable of handling ore as large as four inches in diameter although the normal consistency of the phosphate ore is somewhat like sand.
! In general, the first embodiment of the drilling and mining apparatu9 30, when fully assembled in its mining mode, includes a tool string 36 that extends downwardly through the conductor pipe 37 and has a conventional rotary drill bit assembly 38 at its lower end. It will be under-stood that the bit 38 includes lower cutters 40 and side cutters or underreamers 42 that cooperate to bore a hole or well cavity that is somewhat larger in diameter than the tool string. The side cutters 42 are pivoted inwardly when the tool is being pulled to the surface after the ore ha~ been depleted from the mining site. An eductor pump section 44 iæ connected to the upper end of the drill bit 38, and the mining nozzle section 46 which includes a mining nozzle 46a, is connected to the upper end of the eductor section 44. ~ plurality of dual string pipe J

sections 48 (Fig. 1) are connected toge~her and to the mining nozzle section 46 and extend upwardly to the surface. Each pipe section 48 includes an inner string conduit section 50 (Fig. 2) defining a tubular passage, 5 an outer string conduit section 52 which with the i~ner section 50 defines an outer annular passage, a cavity pressure sensing control line or conduit 54, and a contro line 56 which with the fluid pre~sure within the conduit 50,5Z define a hydraulic control system 57 (Fig. 19)~ The upper end of the uppermost pipe section 48 is connected to a swivel joint 58 that forms a-portion o~ a mining head 60. The mining head 60 includes a threaaea tool su~port coupling 62 that receives and is supported by a : - threaded swivel sub-assembly or drilling head 64.
1~ ~he drilling head 64 is supported by a hydraulic-ally driven power swivel 66 (Fig. 1) of the well rig 35 -- The power swivel 66 is guided for vertical movemen~
along the frame 68 of a drilling mast 70 and is raised and lowered by a power driven 100 ton cable hoist 72. The power swivel 66 ana the hoist 72 are used to support the : tool string 36 during the mining mode of operation and - also ~or raising (or lowering) the tool string a limited amount while mining, if desired, in order to change the -vertical location of a jet of water discharged from the ~ .
mining nozzle for moxe effectively breaking up the granular ore matrix.
The drilling head 64 and power sw;vel 66 are also use~ as a unit to screw each section of the tool string 36 together and to direct water downwardly through the outer conduit 52 and through the drill bit during the ( drilling mode. Similarly, the drilling head and power swivel unit is used to unscrew the pipe sections of the . tool string 36 from each other when the apparatus is being pul~ ed from the well. During the drilling and S pulling modes, a well known drill loading unit 74, torque wrench 76, and tool slip 78 cooperate w}th the power swivel . 66 in a manner well known in the art to perform the dril-; . ling and pulling functions. ~t will also be noted that the mast 70 is pivotally connected to the barge 32 and may be pivoted away from the well as indicated in dct~ed lines to penmit driving the conductor pipe 37 into the upper layer of soil prior to drilling.
In ora~r to ~etter appreciate the several features of the first embodiment of the drilling and mining apparatus - 15 of the present invention, the components of the apparatus -will be described in detailin the order in which they appear in the apparatus from top to bottom.
DRIL~ING HEAD
As mentxned above, the drilling head 64 (Fig. 2) is screwed into the mining head 60 ~or supporting the apparatus 30 during mining~ and is also screwed into each section of the tool string 36 during drilli~g to scrëw the several ~ecti~ns together and to direct water through ~he outer annular conduit 52 and into and through the drill bit 38 during the drilling operation.
The drilling head 64 (Fig. 5) includes an inner string flange 100 and an outer string ~lange 102 rigidly secured to an annular ~lange 104 o~ the power swivel 66 by a pair of centering pins 106 and cooperating cap screws 108. A water distribution tube 110 secured to the ~0639~}0 flange 100 is per~orated to direct ~ter laterally out~rd, ana has its lower end closed by a aiSc 112 and a downwQrdly projecting threaded stub shaft 114. An annular plug 116 is rotatably mounted on the stub shaft 114 and is held in place by a cooperating lock nut 118. The plug 116 is inserted into each inner string conduit section 50 of the tool string during the drilling operation to prevent ~7ater from entering the inner tubular passage of the string except through a small bleed hole 116a provided in the plug 116 for establishing a small downwar~ flow of water that will purge debris therefrom. O-rings or similar flui~ seals 119 are positioned between mating parts to prevent leakage of water therepast when at its drilling pressure of about -300 psig.
An outer hardened pipe section 120 is welded to the outer ~lange 102 and has an externally threaded lower end which is threaded into the box end 121 of each outer pipe section 48 during the drilling operation. During assembl~ and disassembly of the several sections o the tool string 36, relatively moveable upper and lower pipe , ' gripping jaws of the torque wrench 76 (Fig. 1) firmly grip the outer surface of the pipe section 120 and the associated box end }21, respectively, to aid the power swivel 66 in tightly connecting ~or disconnecting) the several sections of the tool string ~ogether. As will become more apparent hereinafter, the inner conduit sections 50 (Fig. 5) of the several interconnected sections of the tool string 36 remain stat,ionary while the outer sections 52 rotate when each outer section is being screwea into or out of the next lower section. The stub shaft 114 of the drilling head is also rotated when screwing the outer sections into or out of the next lower section Thus, the rotatable mounting of the plug ~6 relative to the stub shaft 114 prevents relative motion and possible g~lli~g between ~he outer periphery of the plug 116 and the inner annular sealing surface of the box ends of each inner conduit 50.

The mining head 60 ~Fig. 6) is used durL~g the mining mode and at that time is disposed below the crane supported power swivel 66 and drill~ng head 64, and a~ove the rotata~le tool string 36 to permit the tool string 36 to rotate while the upper portion of the mining head is held from rotation. The head 60 (Fig. 6) incluaes a water inle~ condui~ 130 (Fig. 1) connected to outer conduit 52 ~upplied by a pump P and controlled by a valve 131; a slurry outlet elbow l32 coupled with inner conduit 50; an~ two cont*~ line outlets 134 (only one outlet being shown in ~iguxe 6) connected to control lines 54 and 56, all of ~he above conauits being in fluid sealed relationship relative to each other. The control line outlets each include a three way ~alve 134a and 136a (Fig. 19)~ The control line valve 134a may be selectively contr~lled to connect the control lines 54 to a source of high pressure air for deter-mining well cavity pressure, or to a position ~en~Lng the control line 54 to the atmosphere. The valve 136a may be ~electivel~ controlled to either vent control line 56 to the atmosphere or to connect the line 56 to the system pressure of water supply line 130.
The swivel joint 58 (Fig. 6) o~ the mininy head 60 permits rotation of the tool string during mining ~hile the outer portion of the head above the swivel joint is held from .,. rotation by a torque arm 137 pivotall~ connected to the head by a pin 13~ for movement between the solid line and dotte~
S line positions in Figure 6. Prior to the mining operation, the swivel joint 58 and upper portion of the head are locke~
. from relative rotation by a shear pin 140 thus permitting the mining head to be screwed onto the uppermost pipe section b~ means of the power swivel 66 and drilli~g hea~ -10 . 64 as previously described.
The mining head 60 includes a hardened pipe sleeYe 144 which is screwed into the box end 121 of the outer con-duit 52 o~ the uppermost pipe section 48 and may ~e engage~
by the pivotal clamp jaws or dieQ of the tor~ue wrench 76 (Fig. 1) ~or by other drive mechanisms to be described ~ereinafter) to rotate the tool string in approx~mately 15 increm~nts each five minutes during mining~
The sleeve 144 is welded to a pipe flange 146 .. ~hat i5 connected to the flanged inner ball race 148 of the swivel join* 58 by capscrews 150. The outer ball race .
152 is connected to the lower flange 154 of a pipe tee 156 by cap screws with an annular swivel ring bushing 160 sandwiched therebetween. In order to support the upper section SOa of the inner string 50 from axial moveme~t 2S relative to the'outer string 52 and to seal the ~alls 162 of the swivel j~int ~rom the mining liquid, an annular che~ron t~pe seal 164 and the flange or lugs 165 o~ a collar 16~ welded to the inner stxing 50 are rotatably xeceived between the swivel ring 160 and the upper edge of the inner ball race 148.

The larye pipe tee 156 which includes the ~.~terinlet conduit 130 also includes a flanged connector 158 to which a xelief valve (or rupture disc) RV is connected.
A flange ~7 at the upper end of the pipe tee 156 is rigidl~ connected by cap screws to the flange 168 of the previously referred to threaded tool support coupling 62 which receives the tool supporting drilling head 64 (Fig.
. A ~langa 169 tFig. 6) on the slurry outlet elbow 132 is connected by capscrews to the flange 167, and has a portea annular flange 170' of an inne~ string and control -line gland 170 clamped therebetween in fluid tight engage-ment. The gland 170 includes an inner sleeve 172 having an upper annular control system groove 174 and a lower annular control groove 176 along with three annular seal ring grooves formed in its outer periphery Suitable well known seal rings are placed in the seal ring grooves ~o seal against tne inner surface of a slee~e 182 rigid with a portion of the inner string section 50a thereby ~ealing the control system grooves 174 and 176 in fluid tight engagement from each other and ~rom the inlet water and outlet slurry passages in the apparatus.
Cavity pressure sensing line outlet 134 of control line 54 communicates with the upper contxol syst~m groove 174 through passage 184. A-portion of the passage 184 is fonmed in a block 186 welded in fluid tight engagement to the inner surface d the sleeve 172. Similarl~, the nozzle control line outlet of control line 56 communicates with the lower co~trol system groove 176 through passages 188 (shown in dotted lines in Figure 6), a portion of ~Jhich is formea in a long block 190 welded to the inner surface of , . . .

.

"
~, the sl~eve 172 A control line connector block 192 is welded to the outer surface of the sleeve 182 and includes flow ~assage ~94 which communicates with the passage 184. The upper m~le end of the upper section 54a of the cavity pressure control or sensing line 54 is received in the passage 194 auring assembly of the mining head 60 to define a bayonet type or stab connector 198 wh~h is main-tained in fluid tight engagement by an 0-ring.
Similarly, a block (not shown) which is identical to the bloc~ 192 is welded to the sleeve 182 ana esta-blishes a communication between the passage 188 ana the upper section of the nozzle control line 56. The upper section of the nozæle control line includes a male end portion of a bayonet connector similar to connec~or 192 which is st~bbed in fluid tight engagement with its ~ating female portion.
Like the upper ~nas, the lower end portions o~
the control line sections 54a and 56a are both connected ~0 to the next lower section of con~rol lines 54 an~ 56 by bayonet type connectors 198 (Figs~ 6 and 6~). The lower ends are accurately positxned relative to the inner pipe string 50 ~y apextuxed brackets 204 (only one being shown) rigidly securea to a flanged sleeve 206 that forms the male end of the inner pipe section 50a. The lo~er or male end of each contxol line 54 and 56 are held from axial displacement relative to the brackets 204 by large diameter portions of the control lines 54 and 56 and cooperating snap xings 208. The lower end of the inner string section 50a is maintained in coaxial alignment with the outer string 52 ~y a pluralit~ ~preferably three~ of equall~ spaced ears 210 welded to the sleeve 206 and slidably engaging the inner surface of the sleeve 144 of the outer ~tring.
S The 10Wer end of the inner sleeve 206 i5 providea with a slot 212 (Fig~ 6) having a strengthening strap 214 welded across its inner s~rface. A key 216 bolted to the upper ena of the inner section 50' of the next lower pipe section is received in the slot 212 thus preventing rota-tion between the two inner sectrns. An O-ring 218 seals the two inner pipe sections 50a an~ 50' togethex in fluid tight relationship.
TORQUE WRENC~ 76 The torque wrench 76 is of standard design, identified as Varco Tor~ue Wrench 250 manuactured by ~arco International, Inc., 800 North Eckho~ Street, ~range, California 92668, and accordingly the details of the wrench will not be aescribed. It will suffice to say that the torque wrench includes a lower gripping assem~ly 219 (Figs. 1 and 3~ and an upper gripping a sembl~ 220 both o~ which include pivotal gates 219a, and 220a which gates m~y be pivotally opened to receive the tool string and thereafter independently closed into frictional clamp-ing engagement with the several sect~ons of the tool string 36. After ~eing positioned around the tool string, the upper gripping assembly 220 may be pivo~ed th~ough an angle up to a~out 27 re~tive to the non-rotatable lower gripping asse~bly 219 to either tighten or unscrew the several sections of the tool string 36 ~rom each other, or to intexmittently xotate the tool string 36 during mining.
_21-~063930 Al~hough the details o~ the torque wrench per se are not critical to the presen~ invention, the structure for mounting the torque wrench on the barge 32 does form a part of the invention since it provides means o~ relieving bending forces on the tool string due to relative mov2ment between the barge 32 and the tool string 36. In this regard, the barge, although anchored, tends to drift small amounts relative to the tool string 36, ana also tends t~
roll about the longitudinal axis o~ the barge and pitch to a lesser ~xtent about the transverse axi~ of the barge.
Having reference to Figure 1, it will be apparent that the drill ~it 38 at the lower end of ~he tool string 36 is held at the bottom o~ the arill hole from any sub-stantial transverse movement and that the arill head 64 and power swivel 66 determines the position of the upper end o~ the 5tring since the power swivel is sliaably guided by the ~rame 68 of the mast 70~ Thus, rolling, pitching or lateral movement of the barge 32 relative to the drill hole or well will cause the upper portion o~ ~he .. ..
tool string 36 to move laterally relative to the torque wrench 76 i~ the torque wrench is xigidly secured to the barge 32~ Although the transverse movement relat~e to a .fixed torque wrench woul~ be only a few inches, the bending ~:
force is applied to the tool stxing betwee~ its upper ana lower ends become dangerousl~ high unless the ~orque ~ench 76 is permitted to freely center itsel~ relative to the , longituainal axis d the tool string 36.
Accordingly, the torque wrench 76 is supported by a carriage 221 (Fig. 3) having U-shaped end portions of transverse beams 222 slidably received on slide bars 223 ~,' , , ~063930 (Fi~s~ 3 and ~) that ~re riyidly supported on the barge 32 and extend longitudinally thereof. A cross-beam 224 rigid with the lower gripping assembly 219 is pivotally connected to the carriage 221 by parallel linX~ 225 One end of a carriage advancin~ hydra~llic cylinder 226 is pivotally con-nected to the barge frame while its piston rod 227 is pivotally connected to one of the transverse beams 222.
Springs 228 are connected between pins 229 on the beam 222 and a pin 230 on the cross bar 224 to center the torque wrench 76 when the wrench is not in engagement with the tool string 36. Thus, the cylinder 226 when activated moves the torque wrench 76 between the solid line positio~
~ig. 3) at which time the wrench is in an inoperative position ~paced from the tool string 36, and the operative tool engaging position illustrated in dotted lines with the upper gripping assembly 220 being shown in a pivoted position relative to the lower assembly 219.
After the torque wrench 76 has been clamped around the tool string 36, the valve (not shown) con-trolling the hydraulic cylinder 226 is placed in a neutral position permitting free movement of the piston rod 227 The parallel pivot linXs 225 will accommodate transverse misalignment of the tool string 36 and torque wrench 76 clamped thereon relative to the barge in the direction ~T~ ~ 25 indicated by arrow~ X (Fig. 3)~ The fxeedom o~ movement of the piston rod 227 within the cylinder 226 accommodates longitudinal misalignment of the tool string 36 and torque ~rench 76 relative to the barge 32 in the direction indi-cated by arrow Z (Fig. 3). Thus, the structure for sup-porting the torque wrench permits the torque wrench to ~, ,~
,.................................. .

~ ~0 ~ 39 30 perform its several functions without applying a bending force on the tool string 36 due to misalignmen~ between the barge 32 and the tool string 36.
As mentioned above, the upper gripping assembly 5 220 m~y ~e p;voted through an angle o~ 27 (or any smaller angle) in either direction relative to the lower gripping assembly 219 by hydraulic cylinders 232. Other h~draulic cylind~s (not shown) in each assembly are indepenaently activated to alternately clamp and release the threadea joints between the several tool sections when the sections are being screwea together or are being unscrewea. ~en the torque wrench 76 is being used to intermittently index the tool string 36 during mining, the lower assembly is loosely received around the string and the jaw5 o~ the tool slip 78 are released from gripping engagement with the tool string. The upper gripping assembly 220 i8 clampea in gripping engagement with and rotates ~he tool string about 1~ in about 5 seconds and is then loosened for appr~ximately 5 minutes at which time it is again clampea to repeat the ~ycle of operation. It will be understood, however, that the tool string 36 may be rotata~ly indexea through different angular ranges ~or dif~e~nt time intervals if desired.
As indicated previously in the general description 2S of the illustrated embodiment o~ the invention, ~he drilling heaa 64 ~Fig. 1), which head is connected to the power swivel 66 and is suppor~ed by the hoist 72, is used ~nthout the mining head 60 when coupling and uncoupling the several sections of the tool string 36 together; and is used with the mining heaa during mining. During drilling the power , - .

swivel provides the power to rotate the tool string 36, and during mining the torque wrench 76 provides the driving means for rotating the tool string 36.
It will be understood, however, that if desired, the drilling head and mining head may be combined as a unit and used during drilling as well as during mining. When used in this fashion, the power swivel 66 serves only to suspend the tool string 36, and all rotative power is pro-~ded by drive means such as the torque wrench 76 or the drive means illustrated in the second embodiment of the invention described in Wenneborg et al Patent No. 3,730,592.
During drilling, the tool string should be driven at a rate of about 50 - 60 rpm; and during mining the tool string may be driven either continuously or intermittently but preferably at a much slower speed.
DUAL STRING PIPE SECTIO~S 48 Since the mining nozzle section 46 and the eductor pump section 44 must be aligned with the particular ore strata being mined, and since the mining occurs between the 200 and 300 foot levels, the plurality of pipe sections 48 (Fig. 1) are not all the same length but are made in sections which vary in length between 10 feet and 20 feet.
Thus, the length of the pipe sections 48 may be preselected and assembled together so as to provide a total length which will properly locate the mining nozzle 46a and the inlet of the eductor pump section 44 in the matrix being mined.
Although the inner string and outer string ~s ~i, 1063g30 portions of the mining nozzle section 46 and the eductor nozzle sec~on 44 are rigidly secured together as will be made apparent hereinafter, it will be understood that the outer section 52 o~ each standard pipe section 48 is 5 rotated relative to both its inner section 50 and the two control lines 54 and 56 during assembl~ or disassembly of the tool string 36. Such relative rotation between the inner and outer sectionq permits the outer section~ -52 to be in~erconnected by screw threaas, which when 10 compared to flanged connection-q is a much faster ana less expensive method of connecting pipe sections together, while the several inner pipe sections 50 and the control line~ -54 ana 5~ are coupled together by stab-~ype ~onn2ctions.
For ease in handling each dual string pipe ~5 section 48, the upper end of the inner section 50 i~ held in axial alignment with, and from axial displace~ent rela- 7 ~ive to, the outer section 52 by conventio~al means which incluaes a ring 230 (Figs. 5 and 6A). The ring 230 is rigidly secured to the inner section 50 by a plurality of 20 radial ears 232 (onl~ one being shown in Fi~. 5) and in-clude a pair o~ apextured portions 234 (only one being shown), for Sliaably receiving and accurately locating the upper end ~ the associatea sections ~ the control lines S4 and 56, The ring 230 is rotatably received in the outer 25 ~ec~ion 52 and is held from axial displacement xelati~e :
thereto between a snap ring 236 secured to the outer section and a thrust ~ushing held by a shoulder 238 foxmed in the outer section.
The lower end of each pipe section 50 is 30 centered xelative to the outer section S2, and the control -26- .

lines 54 and 56 are hel~ in place by ears and bracke~ similar to the ears 210 and the brackets 204 (Fig. 6). It will be apparent that the act of screwing the outer sections together will also cause the inner sections to move axially towara and into sealing relationship with each other. Thus, the joints between each dual pipe section 48 is the same as the joint between the sleeve 144 (Fig. 6) and the adjacent lower pipe section 48.
MINI~G ~OZZLE SECTION 46 The mining nozzle section 46 (Figs. 7-11), after being lowered to its initial mining position~ is positioned in the ore matIix to be mined and includes the nozzle 46a which is closed during drilling and disassembly but is normally opened auring mining. During mining a high ve~ocity jet of water that is between about 1 1/2 to 2 1/4 inches i~
diameter is directed into the matrix to break up the matrix into a s~urry which is pumped to the surface by the eductor pump section 44 therebelow.
The mining nozzle section 46 dif~ers from the previousl~ described sections of the tool string 3~ in that the inner string section 50b is rigidly secured to the outer string conduit section 52b prior to being screwed into the tool string 36~
The inner string section 50b includes an upper male or box end which is similar to the box end portion of the several pipe sections 48 (Fig. 6) previously de-scribed. Two equally spaced ears 300 (Figs. 7 and 9) are welded to the outer sur~ace of the box end to center the ~nner string section 50b with the outer string section 52b, The ears 300 slidably engage the inner surface o~ the upper -27~

s ,~ .

1~63930 box end 121b o~ the ou~er string section 5Zb, thue permitting asse~bly of the tube string sections. The upper inner box end is welded to a pipe section 302 having a fabricated out-wardly bowed portion 304 (Figs. 8 and 10) to per~it large 5 articles having a diamete~ up to about 5 inche~ ,o be movea upwardly thrDugh the inner tube 50b past a nozzle tu~e 306 that is welded transversely acros~ the lower portion of the inner string of the mining nozzle section 46. A small dia~eter tube 308 is welded across the inner pipe section 302 below the nozzle tube and serves as means ~or accurately locXing the inner section to the outer section as will be ~escribed in more detail hereinafter.
Since the inner string sectrn 50b must rotate with the outer section 5Zb when the outer string section 52b is ~crewed into the eductor section 44 therebelow, - the lower end of the pipe section 302 define~ the inner portion of a second inner string ana gland 312 that is similar to the gland 170 (Fig~ 6). The gland 312 includes an upper annular control passage 314, a lower annular control passage 316, and O-ring grooves formed in its outer periphery. O-rings 318 in the O-ring grooves engage the inner surface of the upper box end of ~e inner string ~Ob af the eductor section 44 to seal the control passages 314 and 316 from each other and from the mining water as well as the slurry being pumped to the surface.
; Seotions 54b and 56b (Figs. 8 and 9) of the control lines 54 and 56 are ~onnected in fluid tignt flow communica~ion with the sections of the control lines immediately thereabove by bayonet type connectors 320 and 30 322 bolted to the box end o~ the inner conduit section 50b.

~, , .
. ~ .

~063930 The lower end of the control line section 56b is connected to the upper end of a bayonet type connector 324 (Figs. 8 and 11) secured to the outer surface of the pipe section 30~.
F10~J passages 326 (Figs. 7 and 11) are formed in the con-nector 32~ in the pipe section 302 and in a hollo" box 328 welded to the inner surface of the pipe section 302 to allow control fluid to flow between the line 56b and the annular passage 316 in the gland 312. A flow passage 329 (Fig. 8) similar to passage 326 connects the annular passage 314 to control line section 54b. In addition to the above control lines, a nozzle actuating branch line 330 is connected to control line 56b by pa~sages in ~he -adapter 322 and in a generally oblong cylînder supporting block 332 communicating with a cylinder 334 (Fig. 7).
The outer string section 52b comprises internally threadea upper and lower box enas 121b and 121b' with the lower end 121b' defining a portion of an intermediate pipe 'i section 340. A generally oblong nozzle supporting block f 342 and the cylinder supporting block 332 are welaed to and ~I
seal holes formed in opposite walls of the box end 12I~. i The blocks 332 and 342 (Fig. 7) and the ena portions of the tube 308 are concentrically bored to receive tub~lar `~
pins 346 and 348 which accurately position and lock thè
inner conauit section 50b to the outer conduit section 52b_ The pins are held in place by snap rings 352 ~itted in groo~es in the blocks332 and 342. 0-rings 354 and plugs 356 screwea into threaded portions of the pins 346 and 348 prevent ~ter from entering the tube 308 when it is desired to disassemble the inner string section 50b from the outer ætring section 52b, the plug 356 on at least one of the pins ' 1063930 is unscrewed, and the snap rings 352 are removed. ~he pin~
are either pulled out by a bolt (not shown) threadea into the pin, or by inserting a rod throu~h the tubular pins and then hammering the other pin out with the aid of a loose rod 358 placed in the tube 308 for that purpose~
The mining nozzle 46a includes an apertured nozzle seat 360 (Figs. 9 and lO) which is sealed in a large diameter bore in the nozzle block 342 and in the adjacent .
end of the nozzle tube 306 by O-rings and a snap ring 364. The connection between the nczzle tube 306 and the nozzle seat 360 also serve to hold the inner conduit section ~Ob to the outer conduit section 5Zb~ A bore in the cylinder supportin~ ~lock 332 is formed concentrically with the nozzle seat 360 and has an end plate 366, which incluaes the afore- :
mentioned nozzle cylinder 334, connected therein by cap~crews 368. The o~er surface of the nozzle cylinder 334 is sealea to the block 332 by an O-ring with the cylinder bei~g con-centric with the nozæle seat 360.
. An elongate combined piston and ~zzle plug unit .-370 of the mining nozzle 46a includes a tubul2r body 371 ana a piston 372 with an O-ring seal slidably received in ~he c~ylinder 334. The other end o~ the unit 370 is closed by a aisc 375 having a nozzle plug 376 connected thereto by a capscrew ~o that the plug can easily be replaced when worn. .
The piston and nozzle plug unit 370 iS urgea into the nozzle closing po~ion by a spring 380 disposed wqthi~ the tubular body 371 and applies closing pressure between the end plate - 366 and the aisc 375 o:E the body 371. As illustrated in Figure 8, the piston-nozzle plug unit 370 is guided during its opening and closing movement by a plurality o~ evenly ~, , ,"
. .

spaced guide or ~aightening vanes 382 tha~ are rigidly secured to the unit 370.
When the mining nozzle section 46 is not sub-jected to any substantial liquid pressure, for example, during assembly or disassembly of the several sections of the tool string, the spring 380 will maintain the nozzle closad. When drilling, drilling liquid enters and pas-~es through the mining nozzle section 46 at about 300 psig (surface pressure) in the annular pasqage de~ined between the outer string 52~ and the inner string 50b.
Although an unbalanced pressure of about 100 psig acting on the outer surfaces of the piston and nozzle plug unit 370 i8 suf~icient to overcome the spring pressure and open the nozzle 46a, the approximate 300 psig mining or system pressure is overbalanced when liquid at the same pressure is d~rected into the nozzle cy~nder 334 through control lines 56,56b ana branch line 330. This additional "overbalanced"
closing orce aids the spring 380 to maintain the nozzle closed auring drilling.
20 - This'bverbalancing" force occurs when the - ¦-mining nozzle 46a is closed because the system pressure within the cylinder 334 tending to close the nozzle plug u~it 370 acts on the full piston area, while system pres-sure exerting a force in the opposite direction on the nozzle plug unit 370 acts on the full piston area less that portion of the piston area that is subjected only to cavity pre~sure. As will be apparent, when the mining " nozzle is closed an area that is approximately equal to the area of the aperture in the mining nozzle seat will be subjected only to the very low cavity pressure.

~'' ,, "

l ( ~063930 An important ~eature of the invention is that this "overbalanced" force acting on the piston and plug unit 370 during drilling greatly resists any ~orce tending to open the mining nozzle. Such external forces may occur during mining in the uncased well cavity because the nozzle plug unit 370 may be contacted by rocks or the like, or by accumulations of cuttings that are being forced upwardly between the rotating tool string and the walls of the wel~ -cavity. If the mining nozzle is permitted to be opened by such accumulations, the cuttings ma~ plug the water flow passages in the nozzle 46a thus renderin~ the entire apparatus ineffective to perform its mining function.
During mining the control lines 56,56b and 330, -and accordingly the cylinder 334 are vented to the atmo~-15phere by valves 136a (Fig. 19). Pump P (Fig. 1) on the -~
barge 32 then directs mining water through the mining nozzle section at about 700 to 1000 psig which is more than ample to open the mining nozæle to the pos;tion illustrate~
in Figure 7 thereby directing a high pressure an~ high - 20 Yelocity jet of water into the ore matrix being mined. ~ow-ever, because of water hammer shock problems which would - result if the nozzle was opened at full mining pressure, the initial mining start up pre~sure is greatly reduced -by a valve 131 (Fig. 1) in the m~in water supply line at the surface so that the mining nozzle 46a will open when the pressure is relatively low, for example about lOOpsig.
As the nozzle begins to open, an additional area of the nozzle plug 376 is exposed to opening pressure thus over- ;
coming the spring rate and ~ending to open the nozzle with a snap action force which occurs to some extent even at low pressures. The rate of opening of the nozzle 46a is controlled by friction loses within the control passages which restrict the upward flow in the cont~ line 56,56b . .
and 330. ~lso further restriction may be provided i~
desired by means of the manually controlled valve 136a (Fig. 19) at the surface.
If desired, the mining nozzle 46a can be closed during mining by applying mining flow pre~sure to the control line 56. However, to minimize water hammer effect, the mining pressure should momentarily be reduce~ prior to closing the mining nozzle by either reducing both the pressure and the capacity of the pump P (Fi~. 1) r or b~
partially closing the valve 131.
EDUCTOR PUMP SEC~ION ~4 - 15 The eductor pump section 44 ~Figs. 12-16~ is connected between the mining nozzle section 46 and the drill bi~ 38. This section includes a foot valve 400 leading to the arill bit 38 which is open during drilling and closed during mining. An eductor nozæle 402 is also-includea in the section 44 and is closed during drilling ana open auring mining to draw the ore slurry into the ~-tool string 36 and to thereafter propel the slurry upwardl~ -~
to the surface through the inner string 50 with the aid of a venturi tube 404 which is part o~ the inner string 50.
~s best indicated in Figure 12, which figure is a one-quarter section taken along lines 12-12 o~ Figure 13, the lower box end 121b' of the mining nozzle section 46 is screwed onto the upper externally threaded sleeve 406 o~ the eductor section 44. The sleeve 406 forms part : 30 of the o~er conduit string 52 and is welded to a pipe . -33-,, .

.
!

i.

` 1063930 section 408 that is in tu~n welded to a ~lange 410 ~hich closes the bottom of the pipe section 408 except for a ; central aperture 412 (Figs. 12 and 16) and a pair o~
diametrically opposed arcuate openings that cooperate with fabricated walls to definc water inlet passages 14 and 416 that project downwardly below the eductor nozzle 402.
A lower flange 418 of the venturi tubë 404 i.c se~ed in the central aperture 412 by an 0-ring and a snap ring 422. The venturi tube 404 is shown partiall~ cut awa~ in Figure 12 and is fabricated from several pipe sections of increasing d~ameter that are welded together and have an upper box ena 4~3 which receives the pipe section 302 to define the ou~er portion of the previ~usly describea sealing gland 312.
Connector housings 424 and 425 (Fig;~ 12 and 13~ and a pair of ears 428 welded to the box end 423 coopexate to mainLain axial ~ignment o~ the venturi tube 404 with the outer string ~2. One c~ the ears 428 is received between two suide - blocks 430 to maintain the venturi tube 404 in proper angular ...... .... ..... ..... relation~hip with the outer string components.
~ short outer pipe section 432, a portion of which is fabricated as indicated in Figure 14, includes a pair of diagramma~ically opposed slurry inlet openings 434 and is welded to the pipe section 408 and to an annular flange 435 at its lower end. The aforementionea ~rill bit 38 is screwed into an adapter 436 that is bolted to the annular ~lange 435. A perforated cylinder suppor~ing an-nulus 437 is welded within and extends across the pipe section 432 ~or supporting components to be described later, - and also ~or permitting water to flow therepast. An eductor ; 30 nozzle flange 438 is welded to the pipe section 432 at the ,, .
,~ .

1~63930 lower edge of the slurry openings 434 and is centrally apertured to receive the ~ductor nozzle 402. The flange 438 is also provided with arcuate water passages 414a and ~16a (Fig. 15 which form a portion of the arcuate passages 414 and 416, respectively. The fabricated inlet passages 414 and 416 are formed by walls o~ sufficient strength to trans-mit the necessary drilling tor~ue to the drill bit 38 there-below. The arcuate conduits 414,416 direct all of the water downwardly past the closed eductor nozzle 402 and through the open foot valve 400 and drill bit 38 during drilling without.any of the water passing out o~ the slurry inlet ~pening~ 434. Similarly, during mining all of the water moves aownwardly past the eductor nozzle 402 i~to a chamber -- 446 ~etween the.nozzles 402 and the closed ~oot ~alve 400.
Thereafter, most of the water is blocked by the closed foot valve 400 and rapidly flows upwardly thrcugh the open eductor nozzle 402 and venturi tube 404 to create suctio~
w~ich draw~ the slurry through the slurry inlet openings ~34 for jet pumping to the surface.
In order to prevent large pieces of ore, rocks or other m~terial from entering the tool string 36, eductor grille~ 460 (Figs. 12,14 and 16) are bolted in each slurry inle~ opening 434. Each grille 460 includes a series of spaced horizontal plates 462 welded at their ends to mounting bars 464. A series of vertical rods 466 are received in holes in the plate~ 462 ana are welded thereto thus defining grilles - which as illustrated have entrance openings of about 2 1/2"
x 2 1/2" but may be as large as about 4" x 4" if desired.
As illustrated in Figuxes 12 and 16, the eductor nozzle 402 and foot valve 400 axe operatively interconnectea /
,. . .
~' ~06~930 by a piston 470 which is eff2ctive to open the foot valve when the eductor nozzle is closed, and to clo~e the foot ; valve when the eductor nozzle is open. The eauctor nozzle ~02 comprises a frusto-conical apertured nozzle seat 472 having an elongated cylindrical port 473. The seat 472 i5 secured in fluid tight engagement in the central opening o~
the flange 438 by a snap ring 474, an 0-ring seal and a hold-down ring 478 bolted to the flange ~38.
Since the nozzle 40~ must be cl~sed during dril-ling and is subjected to considerable wear due to high velocity water passing therethrough during mining, a nozzle plus 480 (Fig. 16) is proaded with a remova~le sealing portion and is also shiftably mounted so tha~ it may enter and seal the rather long cylindrical nozzle port 473 without binding. ,' The nozzle plug 480 includes a flanged tubular ' ~ody 482 that is bolted to a centrally apertured spring retaining disc 484 and projects upwardly therefrom. A seal - ring 4~6 and sleeve 488 are fitted around a nozzle'stem 490 having an enlarged frusto-conical head 492 at i~s upper end. ~he stem 490 is rigidly secured in the tubular' - body 482 by a pin 494. The nozzle plug 480 is actua~e~ b~
the piston 470 which includes a pis~on roa 496 pro~ecting ' out both ends thereof. The upper end of the piston rod , - 25 is loosely received in the aperture in the spring retaining disc 484. T,he aperture has a frusto-conical upper surface which mates with thefcusto-conical lower suxface o~ a , ring 498 that is held on the piston rod 496 by a snap ring 500. It will be noted that a spring 502 urges the aisc 484 upwardly away from the piston 470 thus permitting ,~ , pivotal and/or transverse movement of the nozzle plug 480 relative to the frusto-conical seat of the ring 498 .~ Upward movement of the nozzle plug 480 is limited by a plurali~y of shouldered pins 504 which abut against the nozæle seat 472.
The piston 470 is received in a cylinder 510 and is sealed thereto by an 0-ring 512, The lower end of the cylinder 510 is clo-~ed by an apertured disc 514 which slidably receives the lower portion of the piston rod 496 ana is sealed by an 0-ring 516. The disc 514 supports one .end of the spring 502 and is rigidly secured to the afore- -mentioned cylinder supporting annulus 437 by a plurality of tubular spacers 518 and capscr~ws extending thsrethrough.
~ he foot valve 400 includes a seat ~20 which lS is sealed to and seated within an annular flange 522 boltea to the drill bit adapter 436 (Fig. 12). A foot valve plug 524 is loosely xeceived on the lower end por~ion of the piston rod 496 and is counterbored to xeceive a compression spring 526, (Fig. 16) which bears against a ring 528 secured to the piston rod 4g6 by a nut 530. Upwar~
movement of the plug 524 is limited b~ a snap ring 53~ and a collar 534 that is sealed to the piston rod and to the upper surface of the plug 524 by 0-rings.
The foot valve plug 524 and a resilient seal ring 536 therein have frusto-conical sealing surfaces which mate with a frusto-conical sealing surface 540 of the seat 520 when the valve is closed. Centering vanes 5~1 enter the bore in the valve seat 520 and, unless perfectly aligned, cause transverse forces to center the resiliently loaded and loosely fitted foot valve plug 524 .

.

by shifting the plug transversely on the piston rod into axial alignment with the seat 520 thus providing a po5i-~ive seal between the frusto-conical surfaces when the Eoot vahe is closed. Ho~ever, it is desirable to direct a certain.amount of water through the drill bit 38 during mining to pr~nt the bit from becoming bound within the drill hole. Accordingly, at least one small diameter ~leed passage 542 is drilled through the plug 524 to permit the desirea amount of water to enter ana flow through the drill bit without-injury to the foot valve sea?ing surfaces as would occur if the *oot valve were partially opened to acco~modate such flow.
As indicated in FigureS 12 and 15, the operation of the ~uctor valve 402 and foot valve 400 is controlled by ~he ~luid pressure in the chamber 446 which acts outsideoE
the c~inaer 510 relative to the pressure within the cy-~inder 510. The pressure within the cy~nder is con~rollea : by the control line 56 which includes conduit section 56c (Figs. 12 and 15) that has its lower end fitted in an . 20 aperture in a ~racket 550. The bracXet 550 is bolted to the disc 514 and the conduit section 56c is secured thereto by a snap ring or the like. A pair of elbows 554 and 556 ana a section of tubing 558 connect the conduit section 56c to a passage 560:leading into the cylin~er 510. The elbow 556 is screwed into a bracket 562 that is bolted to disc 514 and is apertured to receive the lower end of the control line section 54c of the second or cavity pressure sensing control line 54. A section of tubing 564 (Fig. 15) and a pair o~ connectors 566, 568 connect a control line section 54c to a T-section 570 o~ a cavity pressure sensing ~,' '.

tube 572 (Figs. 12 and 15). The tube 572 is ~ealed Dy O-rings to a closed bore in the bracket 550 and a bore 574 in the drill bit adapter 436 which communicates with the interior of the drill ~it 38.
The force applied by the spriny 502 is suf~icient to maintain the eductor nozzle 402 closed and the foot valve 400 open when little or no liquid is in the eductor pump ~ection 44 there~y preventing in~iltration of sand o~ the like into the chamber 446 above the ~oot valve.400.
The spring force is designed to allow the parts to shi~t to the positionY illustrated in Figure 16 at a lo.w un-~alanced supply preqsure in the chamber 446 of about 60 psig.
During drilling, however, the control ~ne 56 and c~inders 510 are subjected to the same drilling pres-sure (about.300 psig) as the pressure in chamber 446 thus overbalancing the hydraulic ~orces thereb~ maintaining the eductor nozzle 402 closed and the foot valve 400 open. The hydraulic force tending to open the eductor nozzle 402 i5 ~:
.. "overbalanced" b,ecause the opening force acting on the portion of the nozzle plug 480 within the cylindrical port 473 is subjected only to cavity pressure, not system pres-sure. The drilling fluid then passes through the arill bit 38 ana washes the cuttings to the surface externatly of the tool string 36. After the several components of the drilling and mining apparatus 30 have been assembled into the mining mode, control line 56 is vented to khe sur~ace and mining water is directed into the tool 36 through the annular passage between the inner and outer conduit strings 50,52. When the unbalanced pressure reaches about 50 psig-.
the eductor nozzle ~02 opens and the foot valve 400 closes.

~, .

., ~063930 After closing the foot valve, the substantial area o the upper surface of the foot valve plug 524 will sense the mining or system pressure thus maintaining the foot valve closed since the cavity pressure below the foot valve is much lower duriny mining. During closing of the foot valve, the restriction in the control line 56 damps the rate of movement of the plug 524 thus precluding any significant water hammer damage.
Ater the system pressur~ has built up to ahout 10 100 psy the mining nozzle 46a (Fig. 7) is opened as previou~ly described to commence breaking up the ore from the partic~ilar strata being mined. With a mining pressure of about 700 to 1000 psig., the jet of water ~rom the mining nozzle breaks up the ore matrix into a slurry, which 15 slurry is dra~m through the slurry openings 434 (Fig. 16 and is pumped to the surface by the ~igh ~elocity ~iquia 10wing through the eauctor nozzle 402. As previously indicated, the tool string is intermittently rotatea during mining.
If it is desired to pump slurry to the surf~ce with the mining nozzle 46a closed, the control pressure in line 56 i5 increased to the min;ng or system pressure thus closing mining nozzle 46a. The Sigh control pres-sure will not, however, permit opening of the ~oot valve 2~ 400 (and closing of the nozzle 402) because of the afore-mentioned large upper and lower surfaces of the foot valve plug 524 and the much greater pressure acting on the upper ~urface.
~f it is desixed to mine ore from another strata, the water supply is cut off thereby closing the mining ,; ., nozzle 46a and the ~uctor nozzle 402, the upper portion of the drilling and mining apparatus 30 is disassem~led and -, new sections are added as the apparatus is drillea deeper until the eductor pump section 44 and mining nozzle ~6a S are prop2rly al~gned with the new strata to be mined. The apparatus 30 is thereafter reassembled into its nining de and the aboe described mining operation is repeated for the new strata being mined.' It will be undes tood ' that if slight height variations are deemea desirable during mining of a strata, that the ent~e apparatus may be raised by the cable hoist 72 (Fig 1). It will also be understood that the well may be initially drilled to its lowest'strata and after mining that strata the apparatus may be raised and disassembled section by section so that ' 15 one or more higher oxe matrixes can be mined after re-assembly of the apparatus into its mining mode.

The rotary drill bit 38 (Fig. 2) may be o~ an~
well known type which includes lower cutters 40 and pivotal side cutters or underreamers 42 that collapse within the ~ody o~ the ~it'when the tool is being li~ted from the well. A suitable underreamex is manufactured by Servco, P.O Box 20212, Long Beach, CA and is known as the Servco Series 15000 Rock Type Underreamer. The underreamer is ' - 25 connected to the lower cutte~ 40 which are of the type manu-facturea by Hughes Tool Company, ALTERN~TE TOOL STRING ROTATIN~ DEVICE 610 As me~ioned previously, the tool string 36 (Figs. 1 and 2) is rotated ox indexed approximately 15 every five minutes by the torque wrench 76 ~Figs. 3 and 4) ' ", .. I

thereby ca~sing the jet of water from the mining nozzle 46a to contact different areas of the ore matrLx being mined. Also, as mentioned previously, the ~epeated engage-ment and disengagement of the jaws of the torque ~rench 76 S with the sleeve 144 (Fig. 6) of the mining head 60 damages the outer surface of the sleeve thus requiring occasional replacement of the sle2ve.
An alternate tool string rotating device 610 (Figs. 17 and 18) comprises a ratchet gear ~12 which is welded or splined to the sleeve 144 o~ the mining ~ead 60.
When the mining head 60 is to be assem~led on the uppermost pipe section, the sleeve 144 i5 first lowered through a clearance hole 614 in disc 616 having a pair of ears projecting outwardly therefrom and pivotally connec~ea to the pi~ton rods 618,620 of hydraulic cylinder 622 and 624, respectively. A pair of ratchet pawls 626 and 628,are - pivo~ea to the disc 616 by shouldered cap screw 63~ and are urged into engagement with the tee~h 632 of the ratchet 612 by compression spring 634 disposed between t~e as~o-ciated pawls and blocks 636 welded to the aisc 616.
- A pair of trunnions 638 a~d 640 are rigidly , secured'to the previously described, carriage 221 tFig, 3) ' and support the hydraulic cylinders 622 and 624, respect-ively, for pivotal movement about ~he axes of pivot pins '; 25 642 and 644, respectively. The high pressure or ~ri~ing ' ends o the hyaraulic cylinde~s 622 and 624 are inter-connected ~y a conduit 646 which is connected by a main conduit 648, having a solenoid valve 650 therein, to a hydxaulic sys~em (not shown). Similarly, a second conduit 652 connects the other ends of the cylinders ~22 and 624 42~

tocJether into a second main conduit 654 of the hydraulic system. Thus, slight transverse misalignment of the baxge relative to the tool string 36 as indicated by the arro~s ~
(Fig. 17) is compensated for by pivotal mover~n~ about pivot pins 642 and G44. Longitudinal misalignment as indicated by the arrows Z is compensated for by differ~nt amounts o~
retraction and extension, respectively, of the piston rods 618,620 during the power stroke which occurs because equal pressure will be applied to both piston rods since they are interconnected by conduit 646. Because the strokes of the two piston rods 618 and 620 will not be the same when compensating for misalignment in the direc~on of arrow Z, an~ ~ecause very high siae loads will result if one piston bottoms before the other, the power to both cylinders must - 15 be shut o~f by closing the solenoid valve 650 when the - first piston bottoms out. To close the valve 650, limit swit~hes 656 and 658 are mounted on the c~inders 622 and 624, respectively, and are positioned to engage s~ops ~60 and 66~ secured to the piston rod 618 and 620, respéct-i~ely. The switches 656 and 658 are connected in parallel ~etween an electrical power source and the solenoid valve ~50. There~ore, the first switch to engage its stop will close the ~alve 650 thereby completing the indexing of the tool strin~. Low pxessure may be directed through the conduit 654,652 to the other ends of the cylinders to return ~he piston rods 618 and 620 to their starting p~sitions illustrated in Figure 17.
~f it is desired to change the angular degree of rotation of the tool strings, the position of the stops 660,662 on the piston rods may be adjusted. It will also ~43-~, :
" .

~063930 be understood that the misalignment between the tool strings 36 and the barge 32 in a direction longitudinally o~ the barge as indicated by arrow Z (Fig. 1) may be partially compens~ted for by placing the piston rod 227 (Fig. 3) of the hydraulic cylinder 226 which oper~tes the carriage 221 in the free moving neutral position.

OPERATIO~t , Although the operatrn of the several components of the drilling and mining apparatus 30 (Figs, 1 and 2) has been included in the detailed description of the component, a summary of the operation of the first embodi- , ment of the invention will follow having reference primarily - to Figures 1, 2 and 19.
The barge 32 is first moved to the mini~g site ' "
1~ and i5 anchored in desired position and the conductor pipe 37 is dxiving into the bottom of the pond 34. The, well drilling rig 35 is then used in conjunction with the drill loading unit 74, the torque wrench 76, and the tool slip 78 to assemhle the apparatus 30 section by sectio~ while ~, 20 drilling the hole or well. During the arilling and assembly operation, the mining head 60 is stored on the deck, and ~he drilling head 64 is screwed into the upper end o~ each ' section o~ the tool string 36 to thread the outer conduit sectrn 5~ together while causing the non-rotatable inner ; 25 sections 50 to move axially into sealing engagsment with ' each other. The power swivel 66 provides the initial torque required to screw ~e eductor section ~4, the mining ~ection 46 and the plurality o~ double string pipe sections 48 together. Final high torque tightening o~ the threads interconnecting each section is provided by the torque '.

1~)63930 wrench 76. After each section is firmly secured to the next lower section, the power swivel 66 acts through ~he mining head 64 to rot~te the drill bit 38 thus drilling the hole.
During drilling after each section of the tool string 36 has been assembled, water at a surface pressure of about 300 psig is directed through the power swivel 66, the drilling head 64 (Fig. 2) and the annular passage between the outer conduit 52 and the inner conduit 50. At this time control conduits 54 and 5~ are open to the drilling pressure, as indicated in Figure 6, thus preventing the drilling water from flowing through ~oth the eauctor nozzle 402 and the mining nozzle 46a (Eig. 19).
The several pipe section~ 48 vary in length ~etween a~out 10 and 20 feet and are so selected that after assembly of the last pipe section 48 on the tool string 36, mining nozzle 46a and the eductor pump 44 are positioned i~
the ore bearing strata or matrix to be mined as indicatea in Figure 2. The mining head 60 is then moved by a crane into position to be receivea and supported by the drilling heaa 64. The power swivel 66 then screws the drilling head ~4 into the mining head 60 and the minin~
heaa 60 into the uppermost pipe section 48. The shear pin 140 (Fig. 6) ~etween the upper portion of the mining head 60 and its swivel joint 58 i5 then removed and the torque arm 137 is pivoted to its solid line position against a leg of the drill rig 35 to hold the upper por-tion of the mining head from rotation. The water inlet conduit 130 and slurry outlet conduit 132, which conduits preferably include long flexible portions tnot shown), ~, ..

~ 063930 are then connected to the mining head 60 thus placing the apparatus in its mining mode of operation.
~ uring mining, the hoist 72, power swivel 66 and arilling head 64 which is screwea ~o the mining head 60 supports the entire apparatus 30 without the aid of the tool slip 78. During mining, the torque wrench 76 (or th~
alternate tool string rotating device 610 Fig. 17~ inter-' mittently indexes or rotates the string below the swiveljoint 58 at a rate deten~ined to be most suita~le ~or the particular type of ore strata being mined. For example, it has been determined that rotation of about 15 every five ~inute~ has beenfibund deqirable for certain ore b~aring strata which is of sandy consistency. Dur;ng this ti~e the structure for mounting the torgue wrench 76 (or alter-1~ 'nate device 610) will compensate for misalignment ~etween the tool string 36 and the barge 32. If helpful to disloage ! the ore ~rom the matrix ~eing mined, the hoist 72 may also be use~ to raise or lower the entire tool strin~ several feet auring mining to re e~ectively direct the jet o~
water from the mining nozzle 46a against tbe ore matrix to reduce ~he'ore to a slurry.
Xn order to control the opening and closin,g o the mining ~ozzle 46a, the eductor nozzle 402, a~d the foot valve 400, the control system 57 (Fig. 19) is employed. The nozzles 46a and 402 are held closed ana the *oot valve is , held open by springs 380,502 when no water pressure is applied ~o the ~ool string 36 or to the control system 57.
When equal w~ter pressure,is applied to the control system ~, 57 and to the tool string 36 as occurs during drilling, ' 30 the mining nozzle 46a and the eductor nozzle 402 are ; -46-,~
~, ~063930 likewise held closed and the foot valve is held open by the springs 380,502 a~ the "overbalanced" hydraulic control pressure acting on the two nozzles as previously described.
During mining, control lines 56 and 54 are vented to the atmosphere and to cavity pressure, respectively. Control lin~ 56 is vented hy opening the valve 136a to the at-mosphere and, if desired, line S4 is connected to a meterea supply o~ high pressure air. With valve 136a vented, water is initially directed into the outer conduit section 52 by the pump P (Fig. 1) at a pressure in excess of about 100 psig. This system pressure exceeds the spring pressure thus opening the mining nozzle 46a and the eductor nozzle 402, and closing the foot valve 400. The pump P then i~-creases the system pressure to about 700 to 1000 psig at which time the ~et of water discharged from the mining nozzle 46a reauces a portion of the ore in the matrix bei~g ' mined to a slurry. Water flowing upwardly through the - eductor nozzle 4~ and the venturi tube 404 then lifts the slurry to the surface for discharge out of the opening 132 (Fig. 6~ and into any suitable collecting means not shown.
I~ ~ is desired to close the mining nozzle 6a during mining in order to lower the water level in ~he cavit~
within the matrix being mined below the level of the nozzle 46a, or for increasing the pumping capability o the eductor pump, the system pressure is first reduced to minimize the water hammer ef~ect by partially closing valve 13~ (Fig. 1) or by otherwise reducing the output pre~ure of the pump P. ' The valve 136a (Fig. 19) is then opened to system pressure thus directing full system pressure into the mining nozzle (~
~063930 cylinder 334 thereby closing the mining nozzle 46a. Minea pressure is thereafter increased to about 1000 psig causing . the flow o~ water through the eductor nozzle 402 to p~p the slurry to the surface. The mining nozzle 46a ma~ again be opened by first red~cing the sy~em pressure, therea~ter opening valve 136a to the atmosphere, and then increasing the system press~re to its normal 700 to 1000 psig mining pressure.
Althcugh full system pressure will also be airected into the eductor valve c~inder 510 when the minLng nozzle is ~eing closed a~ above described, it will be under-stood that the pressure action on the upper surface of the foot valve plug 524 is much greater than the cavity pres-sure acting on the lower surface o~ the closed foot valve lS - plug thus the foot valve will remain closed and the eductor nozzle will remain open at this time.
When the ore within the range of the jet of water discharge from the mining nozzle has been depleted in the particular matrix being mined, the apparatus may be returned to its drilling mode-and either drilled aeeper or raised to another matrix level by adding or removinS
pipe æections without requiring that the entire apparatus be removed from the hole. Before changing ~rom the mining to the drilling mode, the pump P (Fig. 1) is kurned off, 25 t~u5 egualizing the pressure above and below the foot valve plug 524. Thus, the mining nozzle 46a and the eductor nozzle 402 will be closed by the force applied by ~he springs 380 and 502, and the foot valve 400 will be opened. The mining head 60 is then removea and the drilling head is screwed into a pipe section to be added or removed from the tool string 36. The pump is st~rted and water at a~out 300 psig is directed into both control lines and the ou~.er annular conduit 52 in the tool string 36 thus maintain~ng the nozzles clos~d during drilling The nozzles 46a and 402 will remain in their closed positions during drillin~ ~ecause the control pressure plus spring ~o~e provides an adequate force to close the nozzles as pre~-viously described.
Figure 20 illustrates a modified, self activati~g control system 57a. The system 57a acts in response to - ~ariations in the ~stem pressure and the detection of pressure differences between the system pxessure and the cavity pressure. This sel~ activating system, therefore, require no control lines to the surface for operating 1~ the two nozzles and foot valves as above described.
As diagrammatically illustrated, the SyStem includes a conduit 680 which has one end open to receive relatively clean mining water within the outer conduit 52 ~Fig. 12) preferably at a poin~ within the chamber 446 - 20 below the eductor nozzle 402 but above the foot valve 400.
The conduit 680 communicates with one end of a val~e 682 having a shiftable core 684 therein which is normally held in the illustrated nozzle closing position ~y a strong spring 686. A second conduit 688 establishes com-munication ~etween the other end of the valve 682 and the well cavity at a point o~side of the tool string 36 which is at a relatively low pressure during mining and drilling.
The ~onduit 680 also communicates with conduits 6~4 and 696 leading to the mining nozzle cylinder 334 and the eductor nozzle cylindex 510, respectively, through a cross _49_ /

passage 698 in the valve core when the valve core is posi-tioned as illustrated in Figure 20. When the core 684 is :. in the i.llustrated position, system pressure is directed into the c~linders 334 and 510 thereby aiding the springs 380 and 502 to hold the mining noæzle a6a and the eductor nozzle 402 closed and the foot valve 400 open.
Although a drilling system pressure of about 300 psig is insufficient to overcome the force exerted by the spring 686, the 1000 psig mining pressure is sufficient to s hift the valve core 684 downwardly against the urging o~ the spring. At this time, a second cross pa5sage 700 in the core 684 establishes communication between the .. conduit 688 and the conauits 694 and 696 thu~ venting the cylinders 334 and 510 to the relatively low cavity pres- :
15 sure. The higher 700 to 1000 psig system pressure acting on the external surface~ of the mining nozzle 46a and the eductor nozzle 402 will then be sufficient to open the nozzles 56a and 402 ana close the foot valve 400 thus placing these components o the mining and drilling ap-paratus 30 in their mining mode of operation.
A subsequent reduction of system pressure to ab~ut 300 p~ig will cause the spring 686 to return thé
parts to the pos~ion illustrated in ~igure 20 thus causing the 300 psig liquid pressure in the cylinder 334 to close r: 25 the mining nozzles.46a with the aid.o~ its spring 380.
However, the eductor nozzle 402 will not close at ~his pr~ssure since the 300 psig water which flows into the cylinder 510 is not sufficient to open the foot valve 400 because of the large area of the plug 524 and the sub-stantial pxessure differential acting on the upper and -50~
~.. .

,. , lower surfaces of the plug 524 Thus, the mining ~zzle ~6a may be opened or closed during mining by varying the system pressure between the 700 to 1000 psig mining pres-sure ancl the 300 psi~ drilling pressure.
When it is desired to return the apparatus 30 to its drilling mode, the pump P (Fig 1) is stopped thus equalizing the pressure on both sides of the foot valve 400 allowing the springs 502 and 380 to open the foot valve 400 and clo-~e the èductor nozzle 402 and mining nozzles 46a~ Thus, the drilling and mining apparatus 30 may be changed between the mining mode and the driTing mode without requiring that the entire apparatus be pulle~
out o~ the hole, and without requiring any control lines leaaing to the surface.
APPARATUS WITH 1~ MINIl~G I!~TOZZLES
The second embodiment of the inventio~ illustrated in Figures 21 and 22 is substantially the same as the first embodiment of the invention except that it includes a second mining nozzle 46b oriented in a second ore matrix to be mined that is above the first ore matrix. Since the secona mining nozzle is identical to the f~rst mining nozzle, it will not be descri~ed in detail~ Also, since the other components o~ the two embodiments are substan-tially the same, equiva~ent parts of the second embodiment 25 will be assigned the same numerals used to descri~e the - -first embodiment followed by the letter ~x).
It will be understood th~ the second nozzle 46b is spaced from the first mining nozzle 46ax b~ tool string sec~ions of the proper length so that the second nozzle - 30 46b will be in an upper or second ore matrix when the first .

mining nozzle 46ax and the eductor pump section 44x are both in a lower or fixst matrix to be mined. It will also be noted that the slurry from the upper matrix will gravitate downwardly into the cavit~ formed in the lowex matrix so that it can be drawn into the apparatus 30x and be pumped to the surface by the eductor pump section 44x~
In this regard, if the two levels or matrixes being mined are spaced a subdtantial distance from each other, the slu~
will gravitate downwaraly in the space between the apparatu5 ` 30x and the inner surface of the well. If the two ore matrixë~ are cloqe together, the overburden between the two layers is apt to collapse into the lower cavity with substantially all o~ the material being reduced to a slurr~
and pump ~o the surface.
The apparatu~ 30x with two mining nozzles is operated auring drilling and mining i~ substantiall~ the same manner discussed above in regara to the single mining nozzle 5ystem. Thus, only the differences in operation resulting ~rom the addition of the second nozzle 46b will ~e a2~cr~be~ in detail. The cylinder 334b (~ig. 22~ of - the second mining nozzle 46b is connectea to the control conduit ~4x and may be controlled in~epenaently o~ the mining nozzle 46ax by operation of the valve 134ax between a position which vents conduit 54x to the atmos~here tor ~5 to the cavity) there~y permitting the mining nozzle 46b to open, and a position which directs system pressuxe in~o conauit 54x and cylinder 334b thereby holding mining nozzle 46b closea.
During mining, the mining nozzle 46b may be opened and closed without af~ecting the open eductor nozzle ~, .

,, ~063930 402x or the clo ed foot valve 400x because o~ the appli-cation of high system pressure on the large upper surface and low cavity pressure on the lower surface o~ the f oot valve pluy 524x as previously explained in regard to the first embodiment oE the invention.
W~en it is desired to open mining nozzle 46b and close mining nozzle 46ax, the valve 134ax is first-closed to system pressure thus reducing the pressure in - the cavity and in the cylinder 334b of mining nozzle 46~ to cavity pressure. Thereafter, valve 136ax is opened to direct system pressure into the cylinder 334x and 510x thus closing mining noæzle 46ax but retaining foot valve 400x closed and eductor no2zle 402x open because of the diferential pressure acting on the foot valve plug 524~.
W~en the water supply pump is turned of~, the - spring~ 380b,380x and 502x will close mining nozzles 46b, - 46ax and eductor nozzle 402x and open foot valve 400x thus returning the system to its drilling mode, Prom the foregoing description it will be apparent that it is within the scope of the present invent-ion to provide drilling and mining apparatus having either one mining nozæle or a plurality of mining nozzles_ The mining nozzles reduce the ore to a slurry, ana an eductor pump section pumps the slurry to the surface ~or'collection., An interconnected foot valve and eductor nozæle in ~he eductor pump section, and the mining nozzle (or nozzles) are selectively controlled for movement between ~pen and closed positions ~ hydraulic control systems responsive to pres-sures equal to or less than the system pressure. One of the control system~ i~ operated b~ control lines lead~ng to the surface, whereas another control sys~em is aevoid of control lines to the surface and is self-activated by differences between the cavity pressure and the sy~tem pressure within 5 the ~pparatus as determined by control of the water supply entering the drilling and mining apparatus frc~n the surface.
During mining the entire tool string below a mini~g head swivel joint is intermittently rotatea to direct a jet of water from the mining nozzle against diffeEnt portions of the ore matrix being reduced to a slurry. During rotation, means are provided to minimize any unbalance~ side loads on the tool string.
Although the best mode contemplated for carrying out the present invention has been herein shown and de-scribed, it will be apparent that modification and varia-- tion may~e made without departing from ~hat is regarded to be the subject matter of tha invention.
A~M:lw . . .

, -54-,, .

Claims (17)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a method of drilling a hole into and mining ore from a subterranean deposit of granular ore with ap-paratus including a multi-section tool string having a drill bit on its lower end; and a mining nozzle and a foot valve intermediate the ends of the tool string with each being movable between a drilling mode and a mining mode of operation comprising the steps of: alternately rotating and holding the outer portion of a multi-section tool string from rotation for screwing the outer portions together while assembling the string section by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial quantity of liquid during the drilling mode at system pres-sure through the foot valve into the hole for washing cut-tings to the surface, closing the foot valve and opening the mining nozzle during the mining mode for terminating the major quantity of liquid flow into the bottom of the hole, directing a high pressure stream of liquid trans-versely of the tool string through the mining nozzle into the ore matrix to reduce the ore to a slurry, rotating the tool string during mining, and selectively controlling the opening and closing of the mining nozzle and foot valve while the tool string is in the hole by applying a control pressure equal to the system pressure during drilling for maintaining the mining nozzle closed and the foot valve open, and by applying a control pressure less than the system pressure during mining for opening the mining nozzle and closing the foot valve.

2. A method according to claim 1 wherein the control pressure during mining is established by venting to atmospheric pressure.

3. A method according to claim 1 wherein the control pressure during mining is established by venting to cavity pressure.

4. A method according to claim 1 wherein the system pressure during drilling is about 300 psig at the surface and wherein the system pressure during mining is between about 700 to 1000 psig at the surface.

5. A method according to claim 1 wherein the mining nozzle is modulated during mining between the open position and closed position without opening the foot valve by alternately varying the control pressure between a vented pressure and a system pressure.

6. A method according to claim 1 wherein a second mining nozzle is operated by a hydraulically actuated power means in the tool independent from the power means which actuates said first nozzle and disposed at an elevation different from that of the first mining nozzle, and wherein each of the mining nozzles is shifted from the drilling mode to the mining mode by venting the control pressure to the atmosphere.

7. In a method of drilling a hole into and min-ing ore reduced to a slurry from a subterranean deposit of granular ore with apparatus including a multi-section tool string having a drill bit on its lower end; and an eductor nozzle, a mining nozzle, and foot valve intermediate the ends of the tool string with each being movable between a drilling mode and a mining mode of operation comprising the steps of: alternately rotating and holding the outer por-tion of a multi-section tool string from rotation for screwing the outer portions together while assembling the string section-by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial quantity of liquid during the drilling mode at system pressure through the foot valve into the hole for washing cuttings to the surface, closing the foot valve and opening the eductor nozzle and mining nozzle during the mining mode for terminating the major quantity of liquid flow into the bottom of the hole, directing a flow of liquid upwardly through the eductor nozzle to pump the slurry to the surface, directing a high pressure stream of liquid transversely of the tool string through the mining nozzle into the ore matrix to reduce the ore to a slurry, rotating the tool string during mining, and selectively controlling the opening and closing of the eductor nozzle, mining nozzle and foot valve while the tool string is in the hole by applying a control pres-sure equal to the system pressure during drilling for maintaining the eductor nozzle and mining nozzle closed and the foot valve open, and by applying a control pressure less than the system pressure during mining for opening the eductor nozzle and mining nozzle and closing the foot valve.

8. A method according to claim 7 wherein the control pressure during mining is established by venting to atmospheric pressure.

9. A method according to claim 7 wherein the control pressure during mining is established by venting to cavity pressure.

10. A method according to claim 7 wherein the system pressure during drilling is about 300 psig at the surface and wherein the system pressure during mining is between about 700 to 1000 psig at the surface.

11. A method of drilling a hole into and mining ore from a subterranean deposit of granular ore with apparatus including a multi-section tool string having a drill bit on its lower end; and a mining nozzle, an eductor nozzle and a foot valve intermediate the ends of the tool string, each being movable between a drilling mode and a mining mode of operation comprising the steps of:
alternately rotating and holding the outer portion of a multi-section tool string from rotation for screwing the outer portions together while assembling the string section-by-section, rotating and lowering the tool string while drilling a hole into the ore matrix to be mined, directing a substantial quantity of liquid during the drilling mode at system pressure through the foot valve into the hole for washing cuttings to the surface, closing the foot valve and opening the mining nozzle and eductor nozzle during the mining mode for terminating the major quantity of liquid flow into the bottom of the hole, splitting the liquid flow with a portion of the liquid being directed as a high pressure stream transversely of the tool string through the mining nozzle into the ore matrix to reduce the ore to a slurry and with another portion of the liquid directed upwardly through the eductor nozzle to pump the slurry to the surface, rotating the tool string during mining, and selectively controlling the opening and closing of the nozzles and foot valve while the tool string is in the hole by applying a control pressure equal to the system pressure during drilling for maintaining the mining nozzle and eductor nozzle closed and the foot valve open, and by applying a control pressure less than the system pressure during mining for opening the mining nozzle and eductor nozzle and closing the foot valve.

12. A method according to claim 11 wherein the control pressure during mining is established by venting to atmospheric pressure.

13. A method according to claim 11 wherein the control pressure during mining is established by venting to cavity pressure.

14. A method according to claim 13 wherein the system pressure during drilling is about 300 psig at the surface and wherein the system pressure during mining is between about 700 to 1000 psig at the surface.

15. A method according to claim 11 wherein a first hydraulic power means shifts the mining nozzle and a second hydraulic power means shifts both the eductor nozzle and the foot valve with the eductor nozzle being closed when the foot valve is open; and wherein the mining nozzle is modulated during mining between the open position and closed position without opening the foot valve by alternately varying the control pressure between a vented pressure and a system pressure.

16. A method according to claim 11 wherein a second mining nozzle is operated by a hydraulically actuated power means in the tool independent from the power means which actuates said first nozzle and disposed at an elevation different from that of the first mining nozzle, and wherein each of the mining nozzles is shifted from the drilling mode to the mining mode by venting the control pressure to the atmosphere.

17. A method according to claim 11 and further including the step of moving the tool string vertically during mining to change the elevation at which the liquid passing through the mining nozzle contacts the ore matrix.