US2998076A - High pressure washover tool - Google Patents

Description

R. J. COLEMAN ETAL 2,998,076

HIGH PRESSURE -WASHOVER TOOL 3 Sheets-Sheet 1 Aug. 29, 1961 Filed April 6, 1959 m mmw WM r oc Em J Y A mu 5T ATTORNEYS R. J. COLEMAN ETAL 2,998,076 HIGH PRESSURE WASHOVER TOOL 3 Sheets-Sheet 2 s m oqv E r om m m 6 b m RAY J. COLQEMAN SAMUEL RIDE CORDOVA 'gHOMAS A KENNARD Aug. 29, 196l Filed April 6, 1959 A On mm P Q Q h 5v E\\\\\\\\\\\\\\\\\\\\\\\\\\\:\\N; l III/I mm k 0 m Q R Nu ATTORNEYS Aug. 29, 1961 R. J. COLEMAN ETAL HIGH PRESSURE WASHOVER 'I OOL s Sheets-Sheet :5

Filed April 6, 1959 SAMUEL I. Dr: coRDovA .PAUHHH THOMAS A KENNARD ATTORNEYS ilnited States Fatent P.O. Box 408; and Thomas A. Kennard, R0. Box 723, all of Jennings, La.

Filed Apr. 6, 1959, Ser. No. 804,408 Claims. (Cl. 166-222) This invention relates to an improved high pressure washover tool designed to be used in deep, high pressure wells for freeing the tubing therein when the tubing becomes cemented within the well bore due to dehydration and hardening of the mud therein.

The tool is designed to be used either in cased or open wells and is particularly designed for high pressure wells of great depth.

The method currently in use for freeing tubing from the dehydrated and hardened sand and mud in the well bore is by drilling over the fish with a rotary drilling tool while forcing high pressure drilling fluid therethrough. This method frequently results in irreparable damage to the well casing and in breaking and destruction of the tubing which it is designed to recover. When pieces of broken tubing or casing fall to the bottom of the well it is frequently impossible to recover them and the Well is thus irreparably damaged.

This tool is not a drilling tool and is not designed to be rotated to drill out the cemented tubing. It is primarily a high pressure hydraulic tool, i.e., pressures of from 2003000 p.s.i., average 15.00 p.s.i., which depends upon high pressure jets at its elongate lower end to cut out the hardened and dehydrated mud about the tubing. It has substantially no drilling action other than the washover action of its high pressure jets.

The present tool is designed to Work through high pressure jets without any mechanical drilling or cutting of the impacted mud in the bore and to Wash over the tubing or fish much more rapidly than the drilling tools presently in use. Further, due to the fact that there is no drilling or cutting by the lower end of the tool and no rotation thereof, damage to the well casing and impacted tubing is eliminated, as is breakage of the tubing and attendant damage to the well. The elongate, lower stinger section of the tool is deeply arcuate in cross-section and acts to guide and protect the recovered tubing during the washover operation. Sections of the tubing may be recovered at will during the operation.

The novel washover tool comprises broadly a cylindrical upper section from which extends an elongate, cross-sectionally arcuate stinger provided with jet nozzles at its extremity, both sections of the tool being double-walled to provide a high pressure fluid manifold therewithin. Removable plug and sealing means for the well tubing are provided within the upper, cylindrical section of the tool and have the dual function of sealing off the interior of the cylindrical section of the tool to direct the high pressure drilling fluid through the inner manifold and out through the stinger jets and also to seal off the top of the tubing being recovered.

It is therefore an object of this invention to provide a washover tool which will rapidly and efliciently free cemented tubing and Which will protect both tubing and casing from damage during the washover operation.

It is another object of this invention to evolve such an improved tool which operates solely through hydraulic jets.

It is a further object of this invention to evolve such a tool which will guide and protect the tubing as it is being recovered.

It is a further object of this invention to evolve such a tool which will completely seal oif the tubing from the ice fluid in the well and which will protect the tubing during the washover operation.

It is another object of this invention to expedite the washover operation and eliminate all damage to casing and tubing.

Other and further objects of this invention will become apparent as this specification proceeds.

Referring to the drawings,

FIG. 1 is a sectional view of the upper, cylindrical section of the tool, taken on its longitudinal axis, partially broken away and in phantom, showing the internal plug and sealing gasket structures therein with the tip of the plug entering the upper end of the tubing which is being recovered;

FIG. 2 is a cross section view taken on line Z2 of FIG. 1;

FIG. 3 is a partial longitudinal section View of the outer casing and stinger of the tool, partially broken away, showing the sealing gasket and sealing ring in position in the inner cylindrical section;

FIG. 4 is a longitudinal section View of the head end of the tool showing the plug fully seated in the tubing being recovered and the shear pins of the plug structure sheared off, with the gasket sealing off the tubing;

FIG. 5 is a fragmentary perspective view of the nozzle end of the stinger;

FIG. 6 is a cross-sectional view taken on line 6-6 of FIG. 5;

FIG. 7 is an exploded view, partially in phantom, of the inner cylindrical section with the gasket and plug structures in position for assembly;

FIG. 8 is a perspective view of the outer cylindrical head section and stinger of the tool, partially broken away and in phantom, showing the stinger manifold and curvature;

FIG. 9 is a perspective view of the tool afiixed to the end of the pipe string; and

FIG. 10 is an exploded view of the inner plug structure in position for assembly.

In the drawings, FIGS. 1 and 3, it will be seen that the tool comprises broadly cylindrical upper section 1, which contains the sealing gasket and inner plug structure and is designed to receive the end of the tubing being washed over, and the elongate stinger section 2 which performs the freeing or washover operation on the stuck tubing. The tool, as shown, is preferably formed from two concentric sections of steel pipe 3 and 4, respectively, the inner section 4 being of smaller diameter than outer section 3. Outer section 3 is preferably 5 /2" I.D., inner section 4 being preferably 4 /2 I.D. Both sections are cylindrical at their upper portions, forming the cylindrical upper chamber of the tool, and are thence cut away at the lower extremity of cylindrical section ll to less than one-half of their diameters to provide double-walled stinger section 2, of greater length than section 1, and of arcuate cross section.

In the basic formation of the tool, the inner and outer pipe sections having been appropriately cut away to form the stinger sections, inner section 4 is positioned within outer section 3 and spot welded therewithin. A long weld is then made completely around the edges of the stinger sections thereof and around the open neck N of the cylindrical head section to join inner and outer shells 4 and 3 in a double-walled casing with an internal manifold or chamber 5 provided between the walls throughout cylindrical section 1 and throughout the length and width of stinger section 2.

The upper portions of the inner and outer shells 4 and 3, comprising most of the cylindrical head of the tool, are preferably made in the form of removable cylindrical sections 6 and 7, respectively, provided with screw threads 8 and 9 at their lower, inner peripheries for threaded engagement with mating threads and 11, respectively, at the upper, outer peripheries of inner and outer shells 4 and 3. Cylindrical sections 6 and 7 are made removable for ease of assembly and disassembly of the head structure of the tool. Outer cylindrical'section 7 is preferably of greater length at its upper extremity than inner cylinder 6 and is provided at its inner, upper periphery with screw threads 12 by means of which the tool is screw-threadedly aflixed to the threaded extremity of the pipe string, as will be hereinafter discussed at more length.

Stinger 2 is preferably deeply arcuate in cross section, as shown in FIGS. 5 and 6, to act as a guide for the upper end of the freed tubing into entry neck N of the cylindrical head 1 of the tool and is provided at its lower extremity with a downwardly reduced, pointed toe member 13 about which are disposed high pressure nozzles 14, 15 and 16, preferably /2" in diameter, from which three high pressure fluid streams are emitted to erode and dig out the cemented mud from about the tubing in the well bore. It will be noted from FIG. 5 that nozzle 15 is disposed centrally of toe 13 at its extreme tip and nozzles 14 and 16 are shouldered and disposed laterally of toe 13, equally spaced at its base section at the tip of stinger 2. Further, nozzle 16 is preferably angled outwardly, as shown, to prevent the tool from backing ofi of the pipe string, during operation.

The inner plug and sealing gasket structure of the tool will now be described in detail. As shown, in FIG. 1, cylindrical section 6 of the head section is appreciably shorter and of smaller diameter than outer cylindrical section 7 thereof, i.e. approximately 1", and terminates at its upper extremity an appreciable distance below terminal screw threads 12 of outer cylinder 7. Fluid manifold 5 is thus maintained between outer cylindrical section 7 and inner cylindrical section 6 throughout their lengths, due to their difierence in diameter, i.e., 1". The space between the lower extremity of screw threads 12 and the upper extremity of inner cylinder 6 is provided for the reception of sealing ring 17, which, as shown, is substantially cylindrical in shape and is shouldered and cut away at its lower extremity 18 and is provided about its lower extremity with screw threads 19 which engage inner peripheral threads 20 disposed about the inner, upper periphery of cylindrical section 6. Below screw threads 19 sealing ring 17 carries a. downwardly extend ing, neck portion 21 which is provided about its periphery with a series of elongate ports 22, for a purpose hereinafter to be further discussed.

It will be noted that the inner peripheral wall of'cylindrical section 6 is cut away or attenuated for an appreciable distance below threads. 20' to provide a peripheral recess 23 about its inner circumference, angular shoulder 24 being provided at the lower extremity of this cutaway portion 23 and running peripherally about the inner circumference of cylinder 6. Extending downwardly from shoulder 24 is a rectilinear peripheral recess 25 which is terminated at its lower extremity by rectangular shoulder 26.

The attenuation of inner cylinder 6 below screw threads 20 is for the purpose of seating, and providing fluid access to, a novel sealing gasket 27 which extends completely about the inner periphery of cylinder 6. Sealing gasket 27 is designed to seal 01f the inner plug section of the tool and, after its removal, to form a sealing contact with the outer surface of the well tubing, as will hereinafter be discussed in more detail.

Sealing gasket 27, as shown in FIGS. 1 and 7, is preferably of substantially hourglass shape, in the form of two meeting truncated open cone sections and is preferably formed of heavy neoprene rubber or an analogous resilient sealing material. As shown, gasket27 is preferably constricted at its inner or medial section to provide an inner cylindrical bearing surface 29, which first bears flush against a portion of the outer periphery of the inner plug structure of the tool and subsequently makes a sealing contact about the outer periphery of the well tubing, as it is recovered. Gasket 27 is preferably angled outwardly to its two extremities and is provided at its upper and lower extremities, respectively, with bearing rings 30 and 31, of pewter or analogous metal, which are appropriately vulcanized or otherwise affixedabout its extremities and serve as seating bearings for gasket 27 within inner cylinder 6, as will be further discussed. Disposed about the outer periphery of the lower extremity of gasket 27 is an angular flange 32 which is designed to seat against angular shoulder 24 of inner cylinder 6 when gasket 27 is seated therewithin. Peripheral recess 33 is provided within gasket 27 to receive high pressure fluid, as will be further discussed,

As has been previously stated, the lower neck 21 of sealing ring 17 extends downwardly from screw threads 19 an appreciable distance to bear flush against the upper surface of bearing ring 30 of gasket 27- to maintain gasket 27 firmly seated within inner cylinder 6, as shown in FIG. 1. The upper edge of ring 30 is preferably provided with a series of ports 34 registering with ports 220i sealing ring 17 to permit ready flow of fluid therethrough. Further, due to the cutting back of the inner wall of cylinder 6 and the elongate ports 22 in the lower neck portion of sealing ring 17, registering with ports 34, it will be seen that there is a free passage for fluid from the head of the tool into recess 33 of gasket 27 through the channel 23 between the outer periphery of gasket bearing ring 30 and the inner surface of cylinder 6.

Sealing ring 17 is provided with a series of lateral, rectilinear bores 35, which are preferably four in number, and which are provided with screw threads 36 at their outer extremities. Bores 35 are designed to seat shear pins 37 which register at their inner extremities in corresponding bores 38, disposed in registration with bores 35, about the outer periphery of plug cap 39 of the inner plug structure of the tool. Screw studs 40 are provided in the threaded outer extremities of bores 35 to maintain shear pins 37 in proper position therein. It will be noted that the outer peripheral wall of plug cap 39 is spaced inwardly of the inner peripheral wall of sealing ring 17 to provide a spacing and fluid channel 41 extending completely about the outer periphery of plug cap 39 and communicating with the interior of the head and, through ports 22 and 34, with recess 33 of sealing gasket 27.

Plug cap 39 is provided at its center with a rectangularly disposed, shouldered wire line pick-up stud 42 for registration with the wire line pick-up.

Plug cap 39 is further provided with a series of ports 44 extending through its upper surface communicating with the inner bore of the plug. Plug cap 39 also carries a series of ports 45 extending at a downward angle from its interior to its exterior lower periphery and communicating with ports 22 of sealing ring 17 and with the interior recess 33 of sealing gasket 27. Plug cap 39 is of smaller diameter than sealing ring 17, whereby peripheral spacing 41 is maintained between plug cap 39 and sealing ring 17 when the two are united by means of sear pins 37.

The lower collar 46 of plug cap 39 is rectangularly shouldered and is provided with internal screw threads 47 designed to register with screw threads 48 disposed about the outer periphery of the upper extremity of upper plug section 59. Upper plug section 50 is of appreciably smaller diameter than plug cap 39, providing a considerable space between its outer periphery and the inner periphery of neck 21 of sealing ring 17 and bearing ring 30 of gasket 27. Plug section 50 is preferably cylindrical in shape and is open throughout its length. At its lower extremity plug section 50 is angularly shouldered at 51 and is extended from shoulder 51 to rectilinear neck portion 52, provided with internal screw threads 53.

Lower plug section 55 is also cylindrical in shape and of appreciably smaller diameter than section 50. It is provided about its upper, outer periphery with screw threads 56 which engage threads 53 about the inner periphery of the neck extremity of plug section 50 to join plug sections 50 and 55 as an integral unit. Due to its reduced diameter there is an enlarged spacing between the outer peripheral wall of plug section 55 and the inner peripheral wall of inner shell 4 of the tool.

Sealing gasket 57, of neoprene rubber or other resilient material, is appropriately fixed within recess 53 about the outer periphery of lower plug section 55. It will be noted that the outer surface of sealing gasket 57 extends outwardly at a slight angle from the surface of plug section 55 and terminates at its upper extremity in an angular sealing shoulder 60, designed to make close sealing contact with the interior of the tubing T when plug section 55 is seated therein, as shown in FIG. 4. At its lower extremity plug section 55 is reduced inwardly at 61 to form entering tip 62. Plug section 55 is provided with an inner peripheral shoulder 63, defining its lower extremity. The lower extremity of tip 62 is of considerably smaller diameter than the tubing being recovered to permit ease of penetration of tip 62 into the tubing, as shown in FIG. 1.

Disposed within and seating against inner peripheral shoulder 64 of plug section 55 is spherical ball valve 65, of greater diameter than lower plug section 55. Ball valve 65 is of smaller diameter than upper plug section 50. Thus, ball valve 65 is free to move upwardly in section 59 of the plug structure, but will seat in sealing relationship against peripheral sealing shoulder 64 at the upper, inner periphery of lower plug section 55 when it is moved downwardly within the plug structure. Upon being so seated, ball valve 65 will eifectively seal off the lower section 55 of the plug structure from the upper section 50 thereof. Ball valve 65 is preferably a steel sphere and the peripheral shoulder 64 at the upper extremity of lower plug section 55 is appropriately ground in corresponding curvature whereby the outer peripheral surface of ball 65 will register therewith in tight, sealing engagement. Thus, when fluid pressure is applied to ball 65 from below, ball 65 will move upwardly in section 50, opening communication between the interior bores of plug sections 55 and 50, clearance being provided about its outer surface for the upward passage of well fluids through the bore of plug section 50 and through ports 44 of plug cap 39. Conversely, when fluid pressure is exerted downwardly through ports 44 of plug cap 39 against ball valve 65 it will be forced downwardly in section 50 into sealing registration with annular seat 64 at the upper extremity of section 55 and will seal off the lower section of the plug to the passage of fluid. Due to this sealing action of ball valve 65 high pressure fluid entering the upper extremity of the tool will be forced through the ports 44 in plug cap 39 and through angular ports 45 thereof into the space between the outer wall of plug section 50 and the inner shell of the tool, through ports 22 and 34 and thence into gasket recess 33. This pressure holds sealing surface 29 of gasket 27 under high sealing pressure against the outer peripheral surface of section 5% of the plug and subsequently against the outer peripheral surface of the well tubing being recovered, as will hereinafter be more fully discussed.

Thus, with the inner plug structure completely sealed off by means of ball valve 65 and gasket 27, the only channel of escape for high pressure fluid in the upper chamber of the tool is through the manifold 5 between outer and inner shells 3 and 4 thereof. The high pressure fluid then passes through the elongate manifold 5 running the length of stinger 2 of the tool, from whence it issues at the lower tip of the stinger through jet nozzles 14, and 16, to perform the washover operation against the upper surface of the solidified mud in the casing about the well tubing.

Conversely, when the tool is being lowered into the Well into working position the pressure of the fluid in the well will force ball valve 65 upwardly in plug section 50,

unsealing the inner plug bore and allowing the well fluid to pass upwardly through the plug bore and out through ports 44 in plug cap 39.

As has been previously stated, plug cap 39 is afiixed to the inner Wall of sealing ring 17 by means of shear pins 37, preferably four in number, which quadrantly connect sealing ring 17 and plug cap 39. Shear pins 37 are provided between the outer shell of the tool and its inner plug portion so that once lower plug section 55 is seated Within the open, upper end of the tubing shear pins 37 will shear off, leaving the plug firmly seated, to the upper extremity of lower section 55 thereof, in the top of the tubing, thus sealing the tubing off completely from the ingress of well fluid and permitting the outer shell and stinger of the tool to proceed downwardly in the well, washing over the stuck tubing and freeing it. As the outer shell and stinger of the tool proceed downwardly, freeing the stuck tubing by means of high pressure terminal jets 14, 15 and 16, the freed tubing passes through the upper section of the tool into the pipe string supporting the tool, sealing surface 29 of gasket 27 sealing off about the periphery of the tubing.

When the tool reaches a point in the well where the tubing is cemented tightly against the casing of the well the tool may be rotated, as required, to position the stinger and jets 14, 15 and 16 over the tubing which is frozen against the well casing and the high pressure hydraulic erosion of the jets will Wash outwardly of the tubing and free it from the casing.

Angular shoulder 66 is provided about the lower periphery of upper plug section 50. Shoulder 66 is designed to seat in the open end of the tubing when lower plug section 55 has fully penetrated it and has been scaled therein by sealing gasket 57.

Stinger 2 is preferably on the order of 18 feet in length and is arcuate in cross section. Toe 13 of stinger 2 initially impinges against the upper surface of the hardened mud in which the tubing is embedded and the high pressure jets of drilling fluid issuing from jet nozzles 14, 15 and 16 commence to wash out the hardened mud from around the tubing. -As the downward washing proceeds the upper extremity of the freed tubing is guided within the curved inner surface of stinger 2 and eventually enters the open neck N at the lower extremity of the cylindrical section 1 of the tool, guided thereinto by the arcuate inner surface of stringer 2. As washing over proceeds further and as more tubing is freed, the upper end of the tubing T comes into contact with the tapered tip 62 of lower plug section 55, which enters the tubing and is forced downwardly thereinto until the upper edge of the tubing seats firmly against angular shoulder 66 at the upper end of plug section 55. With the lower plug section 55 thus fully seated within the tubing and sealed therein by gasket 57, further downward movement of the tool on the pipe string shears olf shear pins 37, leaving the plug structure seated in and sealing the top of the freed tubing section. As the outer casing of the tool slides down wardly over the plug section, the inner bearing surface 29 of sealing gasket 27 thereof slides off the lower end of plug section 50 and over the outer periphery of the tubing, effectively sealing the upper portion of the tool ofi about the periphery of the tubing and preventing escape of high pressure drilling fluid thereabout.

The preferred manner of use of the tool in a washover operation to free the stuck tubing in a well is as follows: By means of the internal screw threads 12 at the upper extremity of cylindrical section 7 the tool is screwed to the lower extremity of a pipe section and is lowered into the well. Due to the fact that the diameter of the tool is approximately an inch and a half less than that of the well casing, i.e., 5 /z"/7", the tool will be maintained centered in the well casing during its descent at the end of the pipe string. The tool is lowered into the well until the toe of stinger 2 reaches the point where the tubing is cemented in the dehydrated and hardened mud within the casing and at thispoint the washover operation to free the cemented tubing is begun. This operation is initiated bystarting the pumps at the head of the well and forcing high pressure drilling fluid down the length of the pipe string into the cylindrical head section 1 of the tool. The pressure of this fluid may vary from 200-3000 p.s.i. Optimum pressure for most operations is in the neighborhood of 1500 psi. As has been previously stated, the high pressure fluid forces ball valve 65 downwardly into sealing engagement with peripheral shoulder 64 at the head of plug section 55 of the tool and seals off the interior of the tool, the high pressure fluid passing through bores 44 and 45 of plug cap 39* and thence through ports 22 and 34 into recess 33 of sealing gasket 27 'to maintain sealing surface 29 thereof in close sealing engagement about the outer periphery of upper plug section 50. With the interior plug section of the tool thus completely sealed off, the only outlet for the high pressure fluid entering the head of the tool is through the manifold between its inner and outer shells and thence through the stinger manifold and jet nozzles 14, and 16. The high pressure jets then commence the eroding operation against the cemented surface of the mud in the casing, initiating the washover operation to free the tubing therefrom. As the upper end of the tubing is washed free, and as the stinger 2 of the tool moves downwardly, the free end of the tubing is guided within the arcuate body of stinger 2 toward the entry neck N of the cylindrical upper section of the tool. When sufiicient tubing, approximately 18', has been washed free the upper, open end of the tubing is guided by the arcuate inner surface of stinger 2 into the entry neck N of the head of the tool and, as the tool descends over the tubing, tip 62 of lower plug section 55 seats in the open end of the tubing and slides downwardly therein until the, top of the tubing engages shoulder 66, at the upper end of plug section 55. Further lowering of the tool, as it frees more tubing, shears off shear pins 37, leaving the inner plug section seated in the end of the tubing, as the casing of the tool descends. As previously stated, when pins 37 shear OE, and as balance of the tool descends, sealing surface 29 of gasket 27 slides down oif plug section 50 and over the tubing, sealing it ofi.

The action of the jet nozzles 14, 15 and 16 is as follows:. As the tip 13 of stinger 2 reaches the upper end of the cemented tubing T, center jet 15, at the extremity of tip 13, is aligned with the tubing T and in close proximity thereto. This centering of jet 15 on the tubing results from the arcuate curvature of tip 13 of stinger 2, which causes it to slide over and about the tubing, placing center jet 15 in alignment with the tubing. With the tip 13 of the stinger 2 so centered on the tubing, the pumps are started and high pressure fluid is forced downwardly through the pipe string, through the tool manifold 5 and out through nozzles 14, 15 and 16 in high pressure jets, preferably of from 1000-2000 p.s.i., depending upon the nature and hardness of the cemented mud about tubing T.

As nozzle 15 is located at the extreme end of tip 13 of stinger 2 and is in closest proximity to the surface of the hardened mud its jet will erode more powerfully than the jets from nozzles 14 and 16 and, as it is centered on tubing T, the high pressure jet stream from nozzle 15 digs in and erodes with extreme power directly at the cemented mud bearing against the tubing itself. Lateral nozzles 14 and 16 throw substantially parallel high pressure jet streams laterally to each side of the cemented tubing to erode and loosen the cemented mud to each side of the central area at the tubing being.

eroded by the jet stream from center nozzle 15, This jet action develops a substantially conical area of erosion, centered at the tubing, with its deepest erosion fromthe lowest, center nozzle 15 and shallower erosions from lateral nozzles 14 and.16, spaced higher on tip 13, above center nozzle 15. Thus, the cemented mud beargasses-a ing directly against the tubing is most deeply eroded at the tubing by the heavy erosive action of the jet stream from nozzle 15 and the lateral areas to the sides of the tubing are less deeply eroded by the streams from lateral nozzles 14 and 16. This disposition of the nozzles effects a much faster and more efficient freeing of the tubing, without damage to the tubing, or casing, than was heretofore possible.

Further, due to the fact that lateral nozzle 16 is inclined outwardly at a slight angle, the axis of its jet is at a slight outward angle to the axis of the jet from nozzle 14 and thus sets up a force which prevents the tool proper from backing ofi of the pipe string, to which it is screw-threadedly attached by means of upper screw threads 12.

The action of the jets from nozzles 14, 15 and 16 is, therefore, a most powerful erosion directly at the tubing from lowest and center nozzle 15 and slightly less powerful lateral erosions from upper nozzles 14 and 16, resulting in a conical area of erosion, centered at the tubing, providing a most efiicient and rapid freeing of the tubing from the hardened mud.

Referring to FIGS. 7, 8 and 10 of the drawings, the preferred manner of assembly of the tool is as follows:

As has been previously stated the upper, cylindrical section of the tool is preferably formed of two independent inner and outer cylinders, 6 and 7, the outer, 7, of the diameter of the outer pipe section, the inner, 6, of the diameter of the inner pipe section, both cylindrical sections being internally screw threaded at their lower, inner peripheries to engage corresponding threads on the inner and outer pipe sections. The provision of these two removable cylindrical sections at the head of the tool is for ease of assembly and disassembly of the head structure of the tool.

Thus, in assembling the tool, with both cylindrical sections 6 and 7 removed from the upper end thereof, gasket 27 is first inserted into inner section 6 and is pushed thereinto until its terminal ring 31 bears fully against shoulder 26 at the lower extremity of cylinder 6, flange 32 seating against angular shoulder 24 of cylinder 6. With gasket 27 thus in position within cylinder 6, sealing ring 17 is then screwed downwardly in the screw-threaded neck of cylinder 6 until its lower, orificed extremity 21 bears against the upper edge of upper gasket ring 30, thus maintaining gasket 27 securely in position within cylinder 6.

With gasket 27 thus seated in inner cylinder 6 the inner plug structure is then inserted through sealing ring 17, its reduced lower extremity 55 passing easily through bearing surface 29 of gasket 27 which then slides freely over the lower surface of upper plug section 5%. The plug structure is slid downwardly through sealing ring 17 until shear pin bores35 of sealing ring 17 and bores 38 of plug cap 39 are in registration. Shear pins 37 are then inserted into the bores, joining sealing ring 17 and plug cap 39 in coaxial registration. Screw plugs 40 are then screwed into bores 35 to maintain shear pins 37 in proper position joining sealing ring 17 and plug cap 39 at their quadrants. The inner plug structure is thus properly positioned coaxially within inner cylinder 6. With the gasket and plug structure thus installed in cylindrical section 6 the entire assembly is then screw threadedly aifixed to the inner shell of the tool by means of its terminal internal screw threads and the corresponding threads on the end of the inner shell of the tool. With the inner cylinder structure thus in position in the head of the tool, outer cylindrical shell 7 is then placed thereover and is screwed onto the screw-threaded upper extremity of the outer shell by means of its terminal internal threads. The assembly thus being complete, the tool is ready for use.

After use, when it is desired to replace shear pins 37 and reassemble the inner structure of the tool, outer cylinder 7 is first unscrewed from the end of the outer shell, screw plugs 40 are removed from bores 35 in sealing ring 17 and the plug structure is again slid through sealing ring 17 and gasket 27 until bores 35 and 38 are in registration. New shear pins 37 are then inserted in the bores and the screw plugs are then replaced and screwed down into engagement with the ends of the shear pins 37. Outer cylinder 7 is then replaced over inner cylinder 6 and re-assembly is complete.

As has hereinbefore been stated, the size and dimensions of the tool and its parts may be varied at will, depending upon the type of well being Worked on. the size of the tubing, well diameter and depth. However, the proportions shown should be maintained within reasonable limits. In all installations the outer diameter of the cylindrical upper section of the tool should be appreciably smaller than the inner diameter of the well casing.

The outer diameter of the tip 62 of lower plug section 55 must be smaller than the inner diameter of the tubing being recovered to insure easy penetration of the tubing. The outer diameter of the upper portion of plug section 55 may be only slightly smaller than the inner diameter of the tubing. Shoulder 66 at the lower end of plug section 50 should be of a height approximately equal to the thickness of the tubing.

For conventional wells, in which the casing diameter is 7 inches, the diameter of the cylindrical head section of the tool may be about /2 inches, the length of the cylindrical head section being approximately 12 feet and the length of the stinger section about 18 feet. These dimensions may be varied within wide limits.

Throughout, equivalents may be substituted for the elements of the combination without departing from the spirit of the invention. Thus, a pivoted or other type of valve may be substituted for the ball valve 65. The port arrangement in plug cap '39 may be varied as desired as may the sealing ring and gasket structure, as long as the relations shown are maintained.

The length and dimensions of the tool may be varied within a wide range as long as the basic relations between the elements are maintained.

Attention is directed to the appended claims for a limitation of the scope of this invention.

What is claimed is:

1. In a high pressure washover tool for freeing tubing in wells, a cylindrical upper section, an elongate lower section in extension of said cylindrical section, a fluid manifold extending through both sections of said tool, nozzles at the extremity of said elongate section, a hollow plug member removably aflixed coaxially within the upper section of said tool, sealing means within said upper section bearing against the outer periphery of said plug member and sealing off the upper section of said tool from its interior, a valve in said plug member, a valve seat in said plug member limiting downward movement of said valve therein, an attenuated lower extremity on said plug member seating within the tubing within a well, whereby high pressure fluid entering the upper section of the tool will close said valve and seal oif the upper section of the tool to effect the emission of high pressure fluid from said nozzles at the extremity of said elongate section of said tool.

2. In a high pressure washover tool for freeing tubing in wells, a cylindrical upper section, an elongate lower section extending from said upper section, a fluid manifold extending through both sections of said tool, nozzles at the extremity of said elongate section, a cylindrical, downwardly reduced plug member removably afiixed coaxially within the upper section of said tool, sealing means within said upper section bearing against the outer periphery of said plug member and sealing off the upper section of said tool from its interior, a ball valve in said plug member, a valve seat in said plug member limiting downward movement of said ball valve therein, an attenuated lower extremity on said plug member seating within the tubing within a well, whereby high pressure fluid entering the upper section of said tool will close said ball valve and seal oif the upper section of the tool to eifect the emission of high pressure fluid from said nozzles at the extremity of said elongate section of said tool.

3. In a high pressure washover tool for freeing tubing in wells, a cylindrical upper section, an elongate stinger extending from said upper section, a fluid manifold extending through both sections of said tool, a nozzle at the extremity of said stinger, lateral nozzles disposed above and laterally of said nozzle on said stinger, a hollow plug member removably aflixed coaxially within the upper section of said tool, inwardly extending resilient sealing means within said upper section bearing against the outer periphery of said plug member and sealing oi? the upper section of said tool from its interior, a ball valve in said plug member, a valve seat in said plug member limiting downward movement of said ball valve therein, an attenuated lower extremity on said plug member seating within the tubing within a well, whereby high pressure fluid entering the upper section of said tool will close said ball valve and seal off the upper section of the tool to effect the emission of high pressure fluid from said nozzles at the extremity of said stinger.

4. In a high pressure washover tool for freeing tubing in wells, a cylindrical upper section, an elongate lower section extending from said upper section, a fluid manifold extending through both sections of said tool, a nozzle at the extremity of said elongate section, nozzles disposed laterally of and above said nozzle on said elongate section, a cylindrical, downwardly reduced plug member removably aflixed coaxially within the upper section of said tool, sealing means within said upper section bearing against the outer periphery of said plug member and sealing off the upper section of said tool from its interior, movable valve means in said plug member, a valve seat in said plug member limiting downward movement of said valve means therein, an attenuated lower extremity on said plug member seating within the tubing within a well, whereby high pressure fluid entering the upper section of said tool will close said valve and seal ofi the upper section of the tool to effect the emission of high pressure fluid from said nozzles at the extremity of said elongate section of said tool.

5. In a high pressure washover tool for freeing tubing in wells, a cylindrical upper section, an elongate lower section extending from said upper section, a fluid mani fold extending through both sections of said tool, triangularly disposed nozzles at the extremity of said elongate section, a cylindrical, downwardly reduced plug member removably aflixed coaxially within the upper section of said tool, sealing means within said upper section bearing against the outer periphery of said plug member and sealing off the upper section of said tool from its interior, a ball valve in said plug member, a valve 7 seat in said plug member limiting downward movement of said ball valve therein, an attenuated lower extremity on said plug member seating within the tubing Within a well, whereby high pressure fluid entering the upper section of said tool will close said ball valve and seal off the upper section of the tool to eifect the emission of high pressure fluid from said nozzles at the extremity of said elongate section of said tool.

6. In a washover tool, a cylindrical upper section, an elongate lower section of arcuate cross section extending from said upper section, a fluid manifold extending completely about the interior of said upper section and the length of said elongate lower section, nozzles at the tip of said elongate section for the emission of high pressure fluid from said manifold, a hollow, downwardly reduced central plug member disposed inwardly of said cylindrical section of said tool, coaxial therewith and of smaller diameter than said cylindrical section, shear pins afiixing the upper section of said central plug member to the inner periphery of said cylindrical section of said tool, ports through thecap of said plug member communicating with the interior of saidtool between the outer periphery of said plug member and the inner periphery of said cylindrical upper section thereof, a flexible gasket member seated within the inner periphery of said cylindrical section provided at its restricted central portion with a cylindrical bearing surface. fitting in close, sealing relationship against the lower, outer periphery of the upper section of said plug member and recessed to provide a fluid manifold behind said cylindrical bearing surface thereof, port means aboutthe upper, peripheral extremity of said gasket communicating between the inner recess of said gasket and the interior of said tool, a ball valve freely movable within the upper section of said plug memher, a valve seat about the inner periphery of said plug member above its lower. section limiting the downward movement of said ball valve therewithin, screw threads about the inner, upper periphery of said cylindrical section to engage threads at the lower extremity of a high pressure pipe line, whereby admission of high pressure fluid into the upper section of said tool will seal off its upper section from its interior and will direct high pressure fluid streams from the nozzles at the tip of its elongate section.

7. In a washover tool, a cylindrical upper section, an elongated stinger of arcuate cross section in extension of one side of said cylindrical upper section, a fluid manifold extending completely about the interior of said upper section and the length of said elongated stinger, a nozzle at the tip of said elongated stinger for the emission of high pressure fluid from said manifold, nozzles on said elongated stinger above said nozzle, a hollow, downwardly reduced central plug member disposed inwardly of said cylindrical section of said tool, coaxial therewith and of smaller diameter than said cylindrical section, shear pins affixing the upper extremity of said central plug member to the inner periphery of said cylindrical section of said tool, ports through the cap of said plug member communicating with the interior of said tool between the outer periphery of said plug member and the inner periphery of said cylindrical upper section thereof, a flexible gasket member seated within the inner periphery of said cylindrical section provided at its restricted central portion with a cylindrical bearing surface fitting in close, sealing relationship against the lower, outer periphery of the upper section of said plug member and recessed centrally to provide a fluid manifold behind said cylindrical bearing surface thereof, port means about the upper, peripheral extremity of said gasket communicating between the inner recess of said gasket and the interior of said tool, a ball valve freely movable within the upper section of said plug member, a valve seat about the inner periphery of said plug member above its lower section limiting the downward movement of said ball valve therewithin, screw threads about the inner, upper periphery of said cylindrical section to engage threads at the lower extremity of a high pressure pipe line, whereby admission of high pressure fluid into the upper section of said tool will seal off its upper section from its interior and will direct high pressure fluid streams from the nozzles at the tip of its elongated stinger.

8. In a washover tool, a cylindrical upper section, an elongate stinger extending from said upper section, a fluid manifold extending completely about the interior of said upper section and the length of said stinger, a nozzle at the tip of said stinger for the emission of high pressure fluid from said manifold, lateral nozzles on said stinger above said nozzle, a cylindrical central plug member disposed inwardly of said cylindrical section of said tool, coaxial therewith and of smaller diameter than said cylindrical section, shear pins aflixing the upper extremity of said central plug member to the inner periphery of said cylindrical section of'said' tool, ports through the cap of said plug member communicating with the interior of said tool between the outer periphery of saidplug member and the inner periphery of said cylindrical upper section thereof, a gasket member seated within the inner periphery of said cylindrical section provided at its restricted central portion with a cylindrical bearing surface fitting in close, sealing relationship against the lower, outer periphery of the upper section of said plug member and recessed at its inner portion to provide a fluid manifold behind said cylindrical bearing surface thereof, port means about the upper, peripheral extremity of said gasket communicating between the inner recess of said gasket and the interior of said tool, a valve freely movable within the upper section of said plug member, a valve seat about the inner periphery of said plug member above its lower section limiting the downward movement of said valve therewithin, a shoulder about the outer periphery of said plug member at its medial portion, screw threads about the inner, upper periphery of said cylindrical section to engage threads at the lower extremity of a high pressure pipe line, whereby admission of pressure fluid into the upper section of said tool will seal off its upper section from its interior and will direct high pressure fluid streams from the nozzles at the tip of said elongate stinger.

9. In a washover tool, a cylindrical upper section, an elongate lower section of arcuate cross section extending from said upper section, a fluid manifold extending completely about the interior of said upper section and through said elongate lower section, a nozzle at the tip of said elongate section for the emission of high pressure fluid from said manifold, nozzles on said elongate section above said nozzle, a hollow, downwardly reduced central plug member disposed inwardly of said cylindrical section of said tool, coaxial therewith and of smaller diameter than said cylindrical section, shear means connecting the upper extremity of said central plug member to the inner periphery of said cylindrical section of said tool, ports through the cap of said plug member communicating with the interior of said tool between the outer periphery of said plug member and the inner periphery of said cylindrical upper section thereof, a flexible, recessed gasket member seated within the inner periphery of said cylindrical section provided at its restricted central portion with a cylindrical bearing surface fitting in close, sealing relationship against the lower, outer periphery of the upper section of said plug member and recessed to provide a fluid manifold behind said cylindrical bearing surface thereof, port means about the upper, peripheral extremity of said gasket communicating between the inner recess of said gasket and the interior of said tool, valve means freely movable within the upper section of said plug member, a valve seat about the inner periphery of said plug member above its lower section limiting the downward movement of said valve means therewithin, a shoulder about the outer periphery of said plug member at its medial portion, screw threads about the inner, upper periphery of said cylindrical section to engage threads at the lower extremity of a high pressure pipe line, whereby admission of high pressure fluid into the upper section of said tool will seal off its upper section from its interior and will direct high pressure fluid streams from the nozzles at the tip of its elongate section.

10. In a washover tool, a cylindrical upper section, an elongate lower section of arcuate cross section extending from said upper section, a fluid manifold extending completely about the interior of said upper section and the length of said elongate lower section, a nozzle at the tip of said elongate section for the emission of high pressure fluid from said manifold, lateral nozzles above said nozzle on said elongate section, a hollow, downwardly reduced central-plug member disposed inwardly of said cylindrical section of said tool, coaxial therewith and of smallerdiameter than said cylindrical section, means affixing the upper extremity of said central plug member to the inner periphery of said cylindrical section of said tool, ports through the cap of said plug member communicating with the interior of said tool between the outer periphery of said plug member and the inner periphery of said cylindrical upper section thereof, a flexible, recessed gasket member seated within the inner periphery of said cylindrical section, a cylindrical bearing surface at the center of said gasket fitting in close, sealing relationship against the lower, outer periphery of the upper section of said plug member, a fluid manifold behind the cylindrical bearing surface of said gasket, port means about the upper, peripheral extremity of said gasket communicating between the inner recess of said gasket and the interior of said tool, a valve freely movable within the upper section of said plug member, a valve seat about the inner periphery of said plug member above its lower section limiting the downward movement of said valve therewithin, screw threads about the inner, upper periphery of said cylindrical section to engage threads at the lower extremity of a high pressure pipe line, whereby admission of high pressure fluid into the upper section of said tool will seal off its upper section from its interior and will direct high pressure fluid streams from the nozzles at the tip of its elongate section.

References Cited in the file of this patent UNITED STATES PATENTS 2,094,022 Pennington Sept. 28, '1937 2,113,856 Parks Apr. 12, 1938 2,449,841 Claypool et al Sept. 21, 1948 2,762,438 Naylor Sept. 11, 1956 2,804,927 Hall Sept. 3, 1957

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