US2810439A - Well head attachment for operating tools in a well under pressure - Google Patents

Description

Oct. 22. 1957 o. J. MCCULLOUGH ET AL 2,810,439

WELL HEAD ATTACHMENT FOR OPERATING TOOLS IN A WELL UNDER PRESSURE Filed May 11, 1955 3 Sheets-Sheet 1 Oct 2. 1957 o. J. MCCULLOUGH ET AL 2,810,439

WELL HEAD ATTACHMENT FOR OPERATING TOOLS IN A WELL UNDER PRESSURE Filed May 11, 1955 3 Sheets-Sheet 2 m m/m/es v y A TTOR/Yti) Oc 22. 1957 o. J. M CULLOUGH ETAL 2,810,439

WELL HEAD ATTACHMENT FOR OPERATING TOOLS IN A WELL UNDER PRESSURE Filed May 11, 1955 s sheet -shee 3 ATTORNEY WELL HEAD ATTAEMENT FOR OPERATING TGOLS EN A WELL UNDER PRESSURE Otis Johnson McCullough and Lester W. Toelke, Houston, Tenn, and lra .i. McCullough, Los Angeles, Calif.

Application May 11, 1955, Serial No. 507,706

12 Claims. (Cl. 16677) This invention relates to well equipment and more particularly to an attachment for well casingheads by which flexible cables and wire lines and tools supported thereby may be inserted into well pipes under high pressures.

it is often desirable during operation of a well, such as an oil or gas well, to introduce and operate therein various types of tools and instruments, such as perforat ing guns, cutting tools, pressure or temperature recorders, flow indicators, etc. Such tools and instruments are ordinarily inserted into the well pipes and operated there in by means of flexible cables or wire lines, which may also embody electrical conductors. Where high pressures exist in the wells, the introduction of such tools and in struments is accompanied by considerably difficulty and often serious hazard of blowouts, or other accidents. This is particularly true where the pressures develop in the well during, or as a result of, the operations conducted therein, as after perforating, for example.

Present day well completion practices may include a procedure which employs a permanently installed production pipe or tubing string, generally of relatively small diameter, through which completion of the well and all further production operations are conducted. In this procedure many of the operations must be conducted under high pressures, since one of the important advantages of such procedure is the avoidance of the necessity for killing the well as by pumping in weighted mud, with its consequent disadvantages as well known in the petroleum production industry.

In order, therefore, to conduct the various operations required in connection with such procedures, it is necessary to introduce various tools into the production string, which, as noted, will ordinarily be small diameter pipe, such as standard two or two and one-half inch tubing, by lowering the tools on flexible cable or wire lines. In the case of electrically operated or actuated tools and instruments, the lowering line or cable will include electrical conducting wires encased in suitable insulation and armor.

Because of the high pressures which may be encountered, the tools and cable in accordance with conventional practices are fed into the well through lubricators which are closed at their upper ends by stuffing boxes which are designed to squeeze tightly about the lowering line or cable in order to prevent escape of the pressure fluid and to hold the well under control.

Because of the forces exerted by high well pressures against the tools and cable entering the well, conventional practices have proposed various means to overcome these forces in order to allow the tools to descend into the well. Such means have included inserting in the tool string heavy weights or so-called sinker bars suflicient to overcome the opposing pressure forces; and mechanical feeding devices by which the cable is forcibly urged into the well. Neither these systems nor any other conventional systems serve to overcome the more serious Patented Oct. 22-, 1957 difliculty which is to prevent leakage about the cable or line. Conventional stufiing box devices which have been employed in an effort to meet this difliculty necessarily depend on radial compression about the cable or line to prevent such leakage. The greater the pressure, the tighter must be the compression and the greater is the resulting friction which tends to prevent the tool string from descending into the Well. Also, the compression necessarily applied to the line will often result in serious damage to the line and to electrical conductors embodied therein. Thus, stufling box arrangements are actually self-defeating. When it is considered that often tools and instruments must be lowered many thousands of feet into, and withdrawn from, a well, it will be obvious that the difliculty of running tools rapidly, efliciently and safely under high pressures will be greatly intensified.

Accordingly, it is a primary object of the present invention to provide an attachment for wellheads by which the various difliculties heretofore encountered in inserting and operating flexible cable-supported tool strings in high pressure wells will be obviated or eliminated.

In accordance with the present invention, a well head attachment is provided which comprises an elongated closed casing or housing structure in which the tool string, including the entire cable or wire line supply, is enclosed, the housing structure being arranged to place the interior thereof in open communication with the well.

, By enclosing the cable supply as well as the tool string within a closed housing, the interior of which is in open communication with the well, the well pressure will be equalized throughout the housing and all operations, including lowering and raising of the tool strings and manipulation thereof in the well by means of the flexible cable, may be conducted without the hazard and disadvantages of more conventional systems.

An important object is to provide a well head attachment which includes a closed housing adapted to be placed in open communication with a well pipe under high pressure, said housing having enclosed therein a reel carrying a supply of flexible cable suflicient to lower tools or instruments to any desired depth in the well and to operate the tools in the well.

A further object is to provide a well head attachment which includes a pressure-tight housing enclosing a cablesupply reel, cable measuring devices and tools to be inserted into the well under well pressures, and means for driving the cable-supply reel from the exterior of the housing.

Other and more specific objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates useful embodiments in accordance with this invention.

In the drawing:

Fig. l is a side elevational view, partly in section, of a well head attachment in accordance with one embodiment of the present invention, the cable reel housing being shown in cross-section taken generally along line l-l of Fig. 2;

Fig. 2 is a longitudinal sectional view of the cable reel housing taken generally along line 2-2 of Fig. 1;

Fig. 3 is an enlarged, fragmentary View, in section, of a portion of the cable reel and housing illustrating some of the details thereof;

Fig. 4 is an enlarged, fragmentary view, in section, of some of the details of the cable reel drive mechanism;

Fig. 5 is a sectional view taken generally along line 5-5 of Fig. 1; and

Fig. 6 is a side elevational view of a truck-mounted modification of the invention.

Referring to Fig. l, the well head attachment in accordance with one embodiment of this invention comprises an elongate hollow casing of inverted generally U-shape, designated generally by the numeral 1, which is made up of a number of portions of varying size and shape. which are connected together so as to be in open communication with each other, whereby, together, they constitute, for all practical purposes, a single continuous hollow casing, one end of which is connectible to the top of a conventional Christmas tree structure, designated generally by the numeral 2, which is mounted on a well casing head 3, and which is equipped with the usual blowout preventers 4 and master valve 5.

The portions of the well head attachment which compose the elongated casing 1, comprise a pair of generally vertically disposed tubular line guide nipples 6 and 7 which are arranged to form the legs of the U-shaped casing. The upper ends of the guide nipples are connected in angularly spaced relation to a hollow pulley housing, designated generally by the numeral 8-, which provides an enlargement in casing 1 intermediate the ends thereof. The lower end of guide nipple 6 is connected to an enlarged hollow reel housing, designated generally by the numeral 9, which provides a closed enlargement in casing 1 at its outer end. The lower end of guide nipple 7 is adapted to be connected to the upper end of Christmas tree 2 in co-axial alignment with a well pipe (not shown) which, it will be understood, extends through the Christmas tree and the well head into the well.

Guide nipple 7 may be of any desired length necessary to accommodate the string of tools or instrument, designated generally by the letter T (Fig. l), to be inserted in the well, and will ordinarily be constructed from a plurality of tubular sections 7a, 75, connected end-to-end by suitable couplings 10. The lower end of guide nipple 7 is connectible to the top of Christmas tree 2 by a suitable coupling means 11. Guide nipple 6 may also be made up of a plurality of tubular sections 6a, 6b, to provide the required length for the attachment structure.

Pulley housing 8 (Figs. 1 and 3) comprises a horizontally disposed tubular body 13 having its ends closed by heads 1414 which are secured to the ends of the body by bolts 14a. Sealing gaskets 14b are installed between the ends of the body and the heads. The lower portion of body 13 is provided with a pair of line guide nozzles 15, 16 angularly spaced apart about body 13 and connectible, respectively, with guide nipples 6 and 7 by means of the respective couplings 17 and 18. A pipe nipple 19, fitted with a valve 20, communicates with the interior of body 13 through the wall thereof. Valve 20 may be employed to relieve pressure within housing 8 or for other purposes as may be required in connection with the operation of the device. A pulley shaft 21 extends axially through body 13 and has its opposite ends journalled in heads 14-14, one end of shaft 21 projecting through a head 14 and being coupled in a conventional manner to a flexible drive shaft 22 which is adapted to be driven by the rotation of the pulley shaft 21. High pressure seals Zia-21a are positioned in the heads 14 about shaft 21 to prevent leakage from housing 8 along the shaft. Secured to shaft 21 within housing 8 is a peripherally grooved pulley sheave 23 over which a flexible cable or wire line 24 is trained in passage through the housing between the guide nozzles and 16. Sheave 23 may be employed merely as a guide pulley but preferably will be employed as a measuring sheave, its diameter being calibrated so that each turn of the sheave will represent a predetermined length of the cable moving into and out of the well. The rotation of the sheave is transmitted by flexible shaft 21 to a suitable recording device, such as the odometer 25 shown mounted on reel housing 9 (Figs. 1 and 2).

Reel housing 9 is mounted on a suitable supporting base 26 and comprises a horizontally disposed tubular body 27 provided with flanges 2828 at its ends to which heads 29 -29 are secured by means of bolts 30. Suitable. ring gaskets 31-31 are installed between flanges 28 and heads 29 and 29a to assure pressure-tight closure of body 27. The latter is provided intermediate its ends with an opening 32 into which is secured a line guide nozzle 33 to which the lower end of guide nipple section 6b is connected by means of a coupling 34.

Rotatably mounted inside the reel housing is a cable reel, designated generally by the numeral 35, on which is mounted a supply of the cable 24 sufiicient to extend to the maximum depth in the well at which operations are to be conducted.

Reel 35 comprises a tubular spool 36 having circular flanges 37', 38. at its opposite ends. Spool 35 is mounted on a shaft 39 which extends axially of the body 27 and has its opposite ends mounted in heads 29 and 29a. The shaft is locked against rotation by means of a key 49 which projects from the end of the shaft into a slot 41 provided in head 29 (Fig. 3).

Traversing means is provided between reel 35 and shaft 39 whereby reel 35 may rotate about shaft 39 while also reciprocating longitudinally thereof in order to effect level-winding of the cable on the reel. The traversing means, which is of generally conventional form, includes reversing spiral grooves 42 in the surface of shaft 39 and a traversing key 43 mounted in the bore of spool 36 and projecting into the grooves.

Rotation of reel 35 is effected by means of any suitable drive mechanism which, in the illustrative embodiment, includes a pair of torque rods 44, 45 which extend through the body of spool 36 parallel to the longitudinal axis thereof on diametrically opposite sides of its bore. At one end the torque rods are connected to a thrust ring 46 which surrounds shaft 39 and is rotatable about the shaft on" anti-friction bearings 47. The opposite ends of the torque rods are connected to a ring gear 48 which is rotatably mounted on shaft 39 and is in mesh with a pinion 49 mounted on a drive shaft 50 which extends through head 29a to the exterior of the reel housing (Fig. 4). The outer end of drive shaft 50 extends through a bearing block 51 which is secured to the exterior of head 29a by means of studs 52. The drive shaft is supported in anti-friction bearings 53' and 54 mounted respectively in head 29a and bearing block 51, and a suitable high pressure seal 55 is mounted in head 29a about shaft 50 to prevent pressure leakage from the reel housing about the drive shaft. The outer end of the drive shaft has mounted thereon a sprocket 56 through which power from any suitable source may be connected in order to either drive or to brake reel 35.

In the embodiment illustrated in Fig. 6, the attachtake-off unit 57 from the truck transmission S is shown connected by a drive belt or chain 58 to sprocket 56.

In many well operations, the tools and instruments being run in the well require electric current in connection with their operation, and such tools and instruments will ordinarily be run on a cable or wire line which em bodies electric current conductors. In the illustrative embodiment cable 24 is also an electrical conductor and the reel housing 9 is provided with suitable means by which electric current may be transmitted through the cable from a suitable source at the surface, or for transmitting electrical signals from instruments in the tool string to appropriate receiving instruments at the surface. To provide the necessary electrical connections to cable 24, the dead end 24a of the latter is led to the exterior of the reel through an opening 37a provided in reel flange 37 and the electrical conductor therein is brought to a terminal 59 which is electrically connected to an electrically conductive wiper ring 60 (see Figs. 2 and 3) which is fixedly secured through an insulator ring 61 to the outer face of reel flange 37 to be rotatable therewith. Wiper ring 60 is positioned to make continuous contact,

throughout rotation of reel 35, with an electrically conductive collector rod 62 which extends longitudinally through the reel housing, one end being enclosed in an insulating ferrule 63 and supported in head 29. The other end of the collector rod is provided with a contact plug 64 which is adapted to abut the end of an electrode 65 mounted in head 29a when the latter is bolted in place against the end of body 27. Electrode 65 is enclosed by a pressure sealing insulating sleeve 66 and extends to the exterior of head 29a. The outer end of electrode 65 forms a binding post to which may be connected an electrical conductor 67 leading to a suitable current source, or surface instruments.

As illustrated in Fig. 2, a passageway 68 may be provided through head 29a to which is connected a nipple 69 fitted with a valve 70 by which pressure inside the reel housing may be relieved. A pressure gage 71 may be connected into nipple 69.

In operation, guide nipple 7 will first be erected on the well head, master valve being closed, of course, during rigging-up of the attachment. Cable 24 will be led from the reel through guide nipple 6, thence through pulley housing 8, passing over sheave 23. The end of the cable will be brought out of nozzle 16 and connected to tools T. The latter will then be inserted into the bore of guide nipple 7 and coupling 18 will then be made up.

When all of the connections between the parts of the device have been made tight, master valve 5 may be opened and the pressure in the well allowed to flow into casing 1 until the pressure is fully equalized throughout all portions of the casing, whereby the tools may now descend freely into the well. If the weight of tools is sufiicient, the pull exerted thereby on cable 24 will rotate reel 35 and allow the cable to feed off as the tools descend into the well. In this case power applied to drive shaft 50 may be employed to brake the rotation of the reel. If necessary, driving power may be applied to shaft 50 to cause the reel to rotate in a direction to cause the cable to feed oil as required to lower the tools in the well.

To withdraw the tools, reel 35 will be rotated in the reeling-in direction and when the tools are withdrawn from the well back into guide nipple 7, master valve 5 will be closed and the pressure inside casing 1 may be relieved by opening either valve 20 or valve 70 or both, after which coupling 18 may be broken, or the structure otherwise dismantled to remove tools T.

It will be understood that the several parts of casing 1 will all be strongly constructed in order to contain, without danger of breakage or leakage, any pressures which may be encountered during the course of operation.

The device may be assembled at the well site or may be mounted, as shown in Fig. 6, as a truck supported service unit which may be readily transported from well to well as may be required.

It will be understood that in cases where it may be unnecessary to measure the amount of cable moving into and out of the well, sheave 23 may be simply a guide pulley. In other cases, reel housing 9 may be mounted directly above guide nipple 7 and pulley housing 8 eliminated altogether. It will be understood that the U-shaped conformation of easing 1 is employed primarily to provide greater compactness in the well head attachment to thereby simplify the handling and supporting arrangements for the structure.

To protect the reel mechanism from debris and detritus which might be discharged from the well into the interior of casing 1 when the well is opened to the casing, the portions of the latter, including guide nipple 6 and reel housing 9, may be filled with oil or other liquid to a suitable level, such as indicated at L, to form a liquid seal for these parts which will effectively transmit the well pressure and thereby permit pressure equalization throughout the casing. Ordinarily, enough sealing liquid will be employed to at least fill reel housing 9 to fully immerse the mechanism enclosed therein. The sealing liquid may be well fluid which may discharge from the well during operations therein.

Additional sealing liquid may be fed into the appropriate parts of casing 1 to replace any liquid which may be carried out of the housing 9, for example, by adhesion to the line as it is run into the well or which may be lost from the casing in any other manner. Such additional liquid may be supplied either continuously or at appropriate intervals during operation of the device by any suitable means. As indicated in Fig. 2, nipple 69 may be utilized for this purpose, the nipple being connected to a suitable sealing liquid supply reservoir 72 through a pipe, indicated at 73, which may have installed therein a pressure pump 74 for pumping the liquid into the reel housing and its connected parts under whatever pressure may be required. It will be understood that reservoir 72 may be sufiiciently elevated with respect tow the casing and placed in open communication therewith to equalize the pressures between the reservoir and casing 1 so that the desired liquid level in the reel housing and its connected parts may be maintained automatically gy gravity flow. In the latter instance, reservoir 72 and the connections to casing 1 will be made sufficiently strong to withstand any pressures which may be transmitted from the well to the interior of casing 1.

As an additional protection against the entrance of debris into casing 1, a flexible wiper element E may be mounted in guide nipple 7 near its lower end. This wiper may be of any well known form and construction which will allow free passage of tools T and line 24 therethrough without forming a seal of such tightness as to exert undue friction on the operating line.

It will be understood that various other alterations and modifications may be made in the details of the illustrative embodiments within the scope of the appended claims without departing from the spirit of this invention.

What we claim and desire to secure by Letters Patent 1. A well head attachment for inserting and operating tools and the like in a well under pressure, comprising, an elongate hollow casing connectible to the top of a well to form a pressure-tight enclosure communicating with the interior of the well and adapted to contain the tools to be operated in the well, an enlarged housing forming a part of said casing at a point remote from the well, reel means rotatably mounted within said housing and carrying the entire supply of a flexible operating line required for operation of said tools in the well, drive means for said reel means extending to the exterior of said housing, a second enlarged housing forming a part of said casing at a point intermediate the first-mentioned housing and the well, and pulley means engaged by said line rotatably mounted in said second housing.

2. A well head attachment as set forth in claim 1 wherein said pulley means is a measuring sheave for measuring the movements of said line to and from the well.

3. A well head attachment for inserting and operating tools and the like in a well under pressure, comprising, an inverted generally U-shaped hollow casing having one leg closed at its lower end and the other leg vertically positioned and connectible at its lower end to the top of a well to form a pressure-tight enclosure communicating with the interior of the wall, said other leg having a length sufiicient to accommodate a string of tools to be inserted into the well, an enlarged housing forming the closure at the lower end of said one leg, reel means rotatably mounted in said enlarged housing and carrying the entire supply of a flexible operating line required for operation of said tools in the well, pulley means rotatably mounted within the portion of the casing forming the juncture between said legs, said pulley means being adapted to guide said line in passage through said casing between said reel means and the well, and

means extending through thewall of said housing for driving; said reel: means from the exterior of said housing.

4; A well head attachment as set forth in claim 3, wherein said pulley means comprises a measuring sheave for measuring the movements of said lineto and from thewell; V

5. A well head attachment as set forth in claim 3, wherein said casing has pressure relief'means connected thereto.

6. A well head attachment as set forth in claim 3-, wherein said one leg contains a Body of liquid sufii'cient to at least fill said. enlarged housing,

7. A well head attachment for inserting and operating tools. and the like in' awell under pressure, comprising,

an elongate hollow casing connectible to the topof a well to forma pressure-tight enclosure communicating with the interior of the well and adapted to contain the tools to be inserted and operatedin the well, reel means rotatably' mounted in the interior of the casing at a point spaced from the'well, said reel means carrying-the an elongate hollow casing connectible to the top of awell to form a pressure-tight enclosure" communicating with the interior of the well and adapted to contain' the tools to be operated in the well, a reel means rotatably mounted interiorly of the casing at a point spaced-fromthe well, said reel meanscarrying the entire supply of-aflexible operating linerequired for operation of said tools in the well; and a body of liquid in saidcasing sufiicient to fully immerse said reel means.

9. A- Well head attachment for inserting and operating tools and the like in a well tinder pressure, comprising, anelongate hollow casing connectibl'e' to the top of a well to form a pressure -tight enclosure communicating with the interior ofthe' well and adapted to contain the toolsto-be operatedli'm the well', a reel means rotatably mounted interiorly of the casing at a point spaced from the well, said reel: means: carrying the entire supply of a flexible operating. line required for operation of said tools in the well, a body of liquid in said casing sufiicient to fully' and adapted tocontain the toolsto be operated in the Well, and a reel means rotatably mounted at a point in the interior of the. casing: remote from the well, said reel means carrying the: entire supply of a flexible operating line required for operation of said tools in the well.

12. A well head attachment'according' to claim 11 including means mounted in the casing for measuring the movements of the operatingzline'into and out of the well.

References'Cited irtthefile of this patent UNITED STATES PATENTS Re. 24,086 Summers Nov. 8, 1955 1,695,701 Steiner et all- Dec. 18; 1928 2,383,455 Ahadie Aug. 28', 1945 2,677,427 McKinney et' a1; May4; 1954 2,720,266 Broussardet al. Oct. 11, 1955

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