US3095926A - Apparatus for recovering objects in a well - Google Patents

Description

y 2, 1963 G. E. RUSH 3,095,926

APPARATUS FOR RECOVERING OBJECTS IN A WELL Filed Sept. 3, 1958 5 Sheets-Sheet 1 f. Hus/7 /ZZZ K ,wmw

ATTOR/VfYJ July 2, 1963 G. E. RUSH 3,095,926

APPARATUS FOR RECOVERING OBJECTS IN A WELL Filed Sept. 3, 1958 5 Sheets-Sheet 4 f I/ZM E f Gear 6 E. RuJ/z 7 INVENTQ.

July 2, 1963 G. E. RUSH 3,095,926

APPARATUS FOR RECOVERING OBJECTS IN A WELL Gear 6* E. fPuJ/i y INVENTOR.

ATTORNEYS United StatesPatent Ofitice 3,0fi5,926 Patented July 2, 1963 3,11%,926 APPARATUS FGR RECOVERING OBJECTS) IN A WELL George E. Rush, Odessa, Tex assignor to Houston Oil Field Material Company, Inc. Houston, Tex a corporation of Delaware Filed Sept. 3, 1958, Ser. No. 758,829 7 Claims. (Cl. 166-55) This invention relates to an apparatus for recovering objects lodged in a well and more particularly to an apparatus by which the lodged object is engaged while being cut around to loosen it.

In the drilling of petroleum wells and during the production from such wells various pieces of pipe and other material occasionally become stuck in the well and have to be removed by what is commonly known in the trade as fishing operations with the stuck object commonly referred to as a fish. In one type of fishing operation a washover pipe of larger diameter than the stuck object is lowered to cut around the fish and free it so that the fish may be either removed by another apparatus lowered into the well to engage the freed fish or by a fish engaging means carried with the washover pipe. It is to an improved apparatus of the latter type that the present invention is directed.

It is a general object of the present invention to provide an apparatus for recovering objects in the well which apparatus will free the fish and remove it from the well without the necessity of separately removing any of the apparatus from the well, which allows an upward pull to be placed on the fish at any desired time, which is releasable from the stuck fish at any time, and which permits circulation of drilling fluid through the apparatus.

Another object of the present invention is to provide such an apparatus including a mandrel within a washover pipe whereby longitudinal upward and downward forces and torque in either direction may be applied to the fish at any desired time and yet during any part of the operation the washover pipe may be freed from the mandrel for cutting over the fish and then re-engaged with the mandrel.

A still further object of the present invention is to provide such an apparatus including a mandrel within a washover pipe with a wash passage within the mandrel whereby drilling fluid in the washover pipe is jetted into the vicinity of the lower end of the mandrel during the lowering of the apparatus into a well.

A still further object of the present invention is to provide such a mandrel and washover pipe assembly which is exceedingly simple to construct, operate, and maintain and which is dependable in use.

Other and further objects, features and advantages of the present invention will appear from the description of the presently preferred example, which is given for the purpose of disclosure and which is taken in conjunction with the accompanying drawings where like character references designate like parts throughout the several views, and where,

FIGURE 1 is a side view, partially sectional, of the apparatus being lowered into a cased well bore,

FIGURE 2 is a view similar to FIGURE 1 illustrating the apparatus after it has engaged the fish and the shearable connecting means between the mandrel and washover pipe has been sheared,

FIGURE 3 is a View similar to FIGURE 1 illustrating the washover operation,

FIGURE 4 is a view similar to FIGURE 1 illustrating the removal of the apparatus and fish from the cased well bore,

FIGURE 5 is a view similar to FIGURE 1 illustrating the apparatus of the present invention in position for disengaging it from a fish that cannot be removed,

FIGURE 6-A is an enlarged elevation, partially sectional, of the upper portion of the apparatus of the present invention, in position to be lowered into a well,

FIGURE 6B is a continuation of FIGURE 6-A,

FIGURE 6-C is a continuation of FIGURE 6-B,

FIGURE 7 is an enlarged fragmentary view of the J-slot in-the mandrel,

FIGURE 8 is a view along the line 8-8 of FIGURE 6-A,

FIGURE 9 is an enlarged sectional elevation of the catcher assembly of a modified form of invention with the catcher assembly in released position, and

FIGURE 10 is a view similar to FIGURE 9 with the catcher assembly in engaged position.

Referring now to the drawings, and particularly to FIGURE 1, the invention includes theelongated washover pipe 10 adapted to be moved in a well, theelongated mandrel 12 loosely fitting within thewashover pipe 16, and engaging means secured to the lower end of themandrel 12 for engaging the stuck object in the well, such engaging means being here illustrated as thespear 14.

Referring to FIGURES l and 6-A through 6-C thewashover pipe 10 is made up of different sections threadedly connected together such as thesections 16, 18, and 20 respectively. Additional sections are secured abovesection 16, beginning at the threadedconnection 22, to give sufficient length of washover pipe It) .to carry out the particular washover operation desired. At the lower end of thewashover pipe 10 is provided aconventional cutting shoe 24 here illustrated as being a roughened lower end of thewashover pipe 10 of wear resistant metal. The foregoing construction is conventional and of itself does not constitute the present invention.

Theelongated mandrel 12 includes at its upper end, in the form illustrated in FIGURES 1 through 8, an enlargeddiameter portion 26 closely but slidably fitted by anannular ring 28 made into thewashover pipe 10. Themandrel 12 when in the position illustrated in the FIGURES 1 and 6-A through 6-B is releasably secured in position in thewashover pipe 10 by the releasable connecting means ofshear pins 32 passing through thewashover pipe 10 into the enlargeddiameter portion 26. The internal diameter or the washover pipe 1% at itsannular ring 28 is slightly greater than the external diameter of the enlargeddiameter portion 26 of themandrel 12 and all other portions of themandrel 12 and thespear 14 below thering 28 so that when thepins 32 are sheared thewashover pipe 10 may move downwardly with respect to themandrel 12. Atapered shoulder 33 on the lower side of thering 28 prevents thering 28 from catching on shoulders on themandrel 12 when thewashover pipe 10 is moved downwardly with respect to themandrel 12 as later explained. For ease of construction and adjustability of length themandrel 12 is made up of a plurality of sections including the J-sub 34 which carries the enlargeddiameter portion 26, and theextension sub 36 threadedly secured to the lower end of the J-sub 34 (see FIGURE 6B). Thisextension sub 36 may be of any desired length to give themandrel 12 the length desired for a purpose later herein explained. Threadedly secured to the lower end of theextension sub 36 is thedrain sub 38 to the lower end of which is threadedly secured the safety joint 40 (see FIGURE 6-C).

To prevent fluid from passing between themandrel 12 and the inner wall of thewashover pipe 10 before theshear pins 32 are sheared, suitable packing such as the O-ring 30 is provided in the enlargeddiameter portion 26 at theannular ring 28. As illustrated in FIG- URES 1, 6-A and 6-B themandrel 12 carries a longitudinal fluid passageway from the upper end of themandrel 12 to thedrain sub 38 with fluid communication being established between thefluid passageway 42 and the exterior of themandrel 12 at theport 44 so that drilling fiuid under pressure in the washover pipe 111 above themandrel 12 will be forced from themandrel 12 in the proximity of thespear 14 regardless of the length of theextension sub 36.

Thesafety joint 4% is provided in the event thespear 14 cannot be released from thefish 43 here illustrated as a packer lodged in thecasing 45. Thesafety joint 40 here illustrated includes thepin member 46 threadedly secured at itsupper end 48 to thedrain sub 33. Below itsupper end 48 thepin member 46 is reduced in diameter at theshoulder 49 to form the reduceddiameter portion 56 which extends to the lower end of thepin member 46 and closely fits into thebox member 52 forming the lower portion of thesafety joint 40. Formed in the reduceddiameter portion 56 of thepin member 46 are a pair of J-slots 53, one only being shown, each including a first generallyvertical slot 54 having an opening at the lower end of thepin member 46, atransverse slot 56 communicating with the upper end of the firstvertical slot 54, and a secondvertical slot 58 communicating with thetransverse slot 56 and extending both above and below thetransverse slot 56 with the secondvertical slot 58 being closed at its upper and lower ends. Slidably received in this J-slot 53 is thelug 60 carried by thebox member 52 of thesafety joint 40. Thesafety joint 40 is held in its assembled position as illustrated in FlGURE 6-C byshear pins 62 passing through the box andpin members 52 and 46 respectively.

When thesafety joint 40 is to be operated, that is to separate thepin member 46 from thebox member 52, thepin member 46 is pulled upwardly, as will be explained later, shearing theshear pins 62 allowing thepin member 46 to move upwardly until thelug 60 is at the lower end of the secondvertical slot 58. Thepin member 46 is then moved downwardly and torqued to left as viewed in FIGURE 6-C until thelug 60 is in line with thetransverse slot 56 whereupon thepin member 46 is rotated until the firstvertical slot 54 is in line with the lug 6t Thereupon upward movement of thepin member 46 will allow thepin member 46 to be removed from thebox member 52. by pulling thevertical slot 54 past thelug 60.

The engaging means secured to the lower end of themandrel 12 for engaging the fish may be of any type that engages the fish upon a downward movement, an upward movement, a torque, or any combination thereof and which is released upon a downward movement or a torque or both. The particular engaging means here illustrated is aspear 14 which is described in Patent No. 1,776,989

issued September 30, 1930 to A. C. Bainbridge et al. for a Collapsible Rotary Spear. As illustrated in FIGURES 1, 2 and 6-C thisparticular spear 14 has anupper body 63 threadedly secured to the lower end of themandrel 12 at thesafety joint 40. Depending from thisupper body 63 is aspear mandrel 65 on which is slidably mounted acage 66 provided withslips 64 expanded by the slip expander 68 near the lower end of thespear mandrel 65. Abowspring 70 provides friction between thecage 66 and the internal wall of afish 43. When thespear 14 is being lowered before engagement with thefish 43 thecage 66 is held (by structure not here shown) against theupper body 63 andspear 14 being inserted into thefish 43 as illustrated in FlGURE 2 the friction of thebowspring 70 against the inner wall of thefish 43 allows thecage 66 to be unlocked on torqueing the spear 14'. Upward movement of themandrel 12 moves theslip expander 68 upwardly relative to thecage 66 which is held stationary by thebowspring 70 expanding the slips 64 -onthe slip expander 68 of thespear mandrel 65 thereby causing the slips '64 to grip thefish 43. Setting down -on themandrel 12 moves thespear mandrel 65 downwardly releasing theslips 64 and reverse torqueing of themandrel 12 locks thecage 66 to theupper body 63 of thespear 14 in position for removal of thespear 14 from thefish 43.

No further description of thisparticular spear 14 is necessary as it is fully illustrated in said Patent No. 1,776,989 issued to A. G. Bainbridge et al. andsuch spear 14 as such does not constitute the present invention.

Referring now to FIGURES 6A and 7 there is illustrated the means by which thespear 14 may be torqued in either direction and stressed or moved longitudinally in either direction. Formed in theenlarged portion 27 of themandrel 12 and below its upper end are a pair of J-slots 76 each provided with a firstvertical slot 78 opened at the lower end of theenlarged portion 27, a transverse slot 89 communicating with the firstvertical slot 78, and a secondvertical slot 32 parallel to the firstvertical slot 78 and communicating with the transverse leg 89 with the secondvertical slot 82 being closed at itslower end 64. Formed in the interior wall of thewashover pipe 16 are a pair of inwardly projectinglugs 36 adapted to be slidably received in the J-slots 76. How- 'of cuttings and other material.

ever, the internal diameter of thewashover pipe 10 between theselugs 86 is less than the external diameter of theenlarged portion 27 of themandrel 10 so that downward movement of theenlarged portion 27 of themandrel 12 past thelugs 86 is permissible only to the extent that thelugs 86 move within the J-slots 76.

In operation, the desired amount of washover pipe 19 below theenlarged diameter portion 26 of themandrel 12 is lowered into the well with the upper end of the last section being held above the surface of the earth. Thespear 14, thesafety joint 40, thedrain sub 38 and the desired length of theextension sub 36 are made up and this part of themandrel 12 is lowered into the washover pipe 113 until the upper end of theextension sub 36 extends slightly above the upper end of thewashover pipe 10 projecting from the well. The J-sub of themandrel 12. is placed in the next section ofwashover pipe 10, il-

lustrated in FIGURE 6-A assection 16, in which theannular ring 28 is located. The shear pins 32 are inserted to releasably secure the J-sub 34 to thesection 16 of the washover pipe 11 Thesection 16 of the washover pipe 151 with the J-sub 34 of themandrel 12 in it is lifted into position over the upper end of theextension sub 36 extending upwardly from the portion of the washover pipe 11) extending from the well and the J-sub 34 is then threadedly secured to theextension sub 36. Thesection 16 of thewashover pipe 10 is then threadedly secured to the upper end of thewashover pipe 10 extending from the well and thewashover pipe 10 lowered into the well with additional sections being added to make up the necessary length ofwashover pipe 10. The upper end of the washover pipe 11 (not shown) is then connected to an operating string of pipe and lowered into the well in the position shown in FIGURE 1.

When thespear 14 is lowered sutficiently to enter the open end of theupstanding fish 43, here shown as a packer lodged incasing 46, torque is placed on thespear 14 by rotating the string of operating pipe which rotates the washover pipe 19, and, through the shear pins 32, themandrel 12, causing rotation of theupper body 63 of thespear 14 with respect to thecage 66 because of the friction of thebowspring 70. This releases thecage 66 of thespear 14 and an upward movement on themandrel 12 by pulling upwardly on thewashover pipe 16 moves themandrel 65 of thespear 14 upwardly setting theslips 64 causing thespear 14 to grip thefish 43. Further upward stress placed on thewashover pipe 10 shears the shear pins 32 placing the assembly in the position illustrated in FIGURE 2. During these lowering and setting operations drill fluid in the washover pipe 11 passes downwardly through thewash passage 42 and jets out the port 44- near thespear 14 clearing it After the shear pins 32 are sheared some of the drilling fluid in the washover pipe above themandrel 12 will pass around the outside of themandrel 12 as the O-ring 30 will no longer be at theannular ring 28 of thewashover pipe 10.

After shearing thepins 32 thewashover pipe 10 is freed from themandrel 12 for washing over operations. Thewashover pipe 10 is then rotated and lowered by the operating string of pipe cutting downwardly around thefish 43 as illustrated in FIGURE 3 until thefish 43 is freed and can be removed. In normal washing over operations it is desired to cut as closely as possible around thefish 43 and thus there is not sufiicient room between thefish 43 and thelugs 86 on the internal walls of thewashover pipe 10 to pass around thefish 43. Thus, a length ofextension sub 36 is chosen so that as thewashover pipe 10 lowers after themandrel 12 has been fixed in thefish 43 thelugs 86 will not reach thefish 43 before it is freed.

Upon thefish 43 being freed it will either fall carrying themandrel 12 with it until thelugs 86 passing upwardly in the firstvertical slot 78 of the J-slot 76 strike the upper end of the first vertical slot '78 or if thefish 43 does not fall thewashover pipe 10 may be raised until this occurs as illustrated in FIGURE 4. Thereafter upon thewashover pipe 10 being pulled upwardly by the operating string thefish 43 is lifted out of the well. If at the time thefish 43 falls or thewashover pipe 10 is raised thelugs 86 should not be in line with the bottom end of the firstvertical slots 78 of the J-slots 76 thelugs 86 will bear against theshoulder 87 at the lower end of theenlarged diameter portion 26 of themandrel 12 and support themandrel 12 as thewashover pipe 10 is removed from the well.

If, as illustrated in FIGURE 5, thefish 43 cannot be dislodged then thewashover pipe 10, themandrel 12, and thespear 14 may be removed from the well by manipulation of thewashover pipe 10 by the string of operating pipe so that thelugs 86 are moved upwardly in the firstvertical slots 78 of the J-slots 76 as is shown in FIGURE 4, rotating thewashover pipe 10 so that thelugs 86 move through thetransverse legs 80, and then moving thewashover pipe 10 downwardly until thelugs 86 are at thelower end 84 of the secondvertical slots 32 as illustrated in FIGURE 5. Further downward movement of thewashover pipe 10 will then force thelugs 86 against the closed lower ends 84 of the secondvertical slots 82 moving themandrel 12 andspear mandrel 65 downwardly so that theslip expander 68 of thespear 14 no longer bears against theslips 64. Torqueing thewashover pipe 10 forces thelugs 86 to bear against the sides of the secondvertical slots 82 transmitting torque through themandrel 12 into theupper body 63 of thespear 14 looking thespear 14 in the retracted position illustrated in FIGURE 6-C so that thespear 14,mandrel 12, andwashover pipe 10 may be removed from the well by pulling upwardly on thewashover pipe 10 causing thelugs 86 to rise to the top of the secondvertical slots 82 and support themandrel 12.

In the event thespear 14 cannot be released from thefish 43 then themandrel 12 above thesafety joint 40 and thewashover pipe 10 may be removed from the well by releasing thesafety joint 40. An upward strain on thewashover pipe 10 and consequently themandrel 12 through thelugs 86 will shear the shear pins 62 of the safety joint 40 which shear pins 62 require a greater stress to shear than the shear pins 32 in thewashover pipe 10 so that the shear pins 62 in the safety joint 40 will not inadvertently shear ahead of the shear pins 32. Once the shear pins 62 are sheared and thewashover pipe 10 manipulated until thelugs 86 are in the secondvertical slots 82 of the J-slots 76, downward movement of thewashover pipe 10 will force themandrel 12 downwardly through the action of thelugs 86 at thelower end 34 of the secondvertical slots 82 until thetransverse leg 56 of the J-slot 53 in thesafety joint 40 is aligned with thelug 60 whereupon rotation of themandrel 12 by thewashover pipe 10 will move the first vertical .slot 5'4 of the J-slot 53 of safety joint 40 in line with thelug 60 so that upward movement of themandrel 12 by pulling upwardly on thewashover pipe 10 will clear thelug 60 from thepin member 46 of thesafety joint 40 and allow thepin member 46 to be pulled upwardly with themandrel 12 leaving thebox member 52 of the safety joint 40 in the hole.

Referring now to FIGURES 9 and 10* there is illustrated a modification in which themandrel 12a includes at its upper end a catcher assembly adapted to releasably secure themandrel 12a to thewashover pipe 10 when thefish 43 is freed without the necessity of raising the mandrel to the position illustrated in FIGURE 4. Other than the inclusion of this catcher assembly in the upper end of the mandrel 12-a the form of apparatus is identical to that illustrated in FIGURES 1 through 8.

In this modification the mandrel 12-a includes an elongated slip expander stem threadedly secured at 101 in axial alignment to astem sub 102 which is in turn threadedly secured at 103 to the enlarged diameter portion 26-01 of themandrel 12a. At its upper end theslip expander stem 100 is provided with anaxial cylinder 104 normally open at its upper end to the interior of thewashover pipe 10 as illustrated in FIGURE 10. The fluid passageway 42-11 extending through themandrel 12a communicates with the lower end of thecylinder 104 through theenlarged counterbored portion 106. Slidably mounted in thecylinder 104 is a preferably cup shapedpiston 108 made integral with the lower end of which is ahollow piston rod 110 slidably received in the counterboredportion 106 of thefluid passageway 42a. At the upper end of thecylinder 104 the mandrel 12-a is internally threaded at to hold the externally threaded pistondepressing plug 107, shown in dotted lines, while the apparatus is being assembled as will be later explained. During use of the apparatus theplug 107 is removed. Downward movement of thispiston 100 is limited by contact of thelower surface 112 of thepiston 108 with thelower end 114 of thecylinder 104. Aport 116 is provided at the lower end of thecylinder 104 for escape of fluid below thepiston 108.

The upper end of theslip expander stern 100 has an external diameter loosely fitting the interior of thewashover pipe 10. Below the cylinder 1% the remainder ofslip expander stem 100 is provided with a reduced diamgage thewashover pipe 10 and each is provided on its underneath surface with a taperedportion 134 complementary to and adapted to ride over theslip expander 122. As thus constructed theslips 128 are retracted in the position illustrated in FIGURE 9 when not in contact with theslip expander 122 and do not engage thewashover pipe 10 until theslip assembly 124 is moved upwardly causing theslipheads 130 to ride over the slip expander r122 moving theslipheads 130 outwardly into engagement with thewashover pipe 10 as illustrated in FIGURE 10. Theslip assembly 124 andslip expander 122 are of conventional construction and no further description of them is necessary.

Provided through the wall of theslip expander stem 100 arelongitudinal slots 136 in each of which is vertically movable apin 138 securing theslip assembly 124 to the piston rod whereby vertical movement of the piston 1G8 andpiston rod 110 is imparted to theslip assem bly 124.

The upper end of the stem sub 192 forms an upwardly facingshoulder 14% and the lower end of thecollar 126 forms a downwardly facingshoulder 142 between which shoulders and around the slip expander stem 1% is acompression coil spring 144 urging theslip assembly 124 upwardly toward theslip expander 122 thus tending to set theslips 128 as illustrated in FIGURE 1-0.

In operation of the modified form of device illustrated in FIGURES 9 and 10 the J-sub 34 and all parts of the mandrel 12-4: below it and thespear 14 are secured to gether and into the washover pipe as previously described. The slip expander stem 10! is then secured to thestem sub 102 and the stem sub 1&2 is then threadedly secured to the enlarged diameter portion 26-;1 which is near the upper end of thesection 16 of the washover pipe v10 so that the slip heads 13% are above thesection 16 of thewashover pipe 10. Because thecoil spring 144 will be holding the slip assembly 1214- in an upward position expanding theslips 126 the next section of thewashover pipe 10 will not pass over the slipheads 130. The pistondepressing plug 107 is engaged in thethreads 105 at the top of the cylinder 1% and screwed downwardly depressing thepiston 108 and retracting theslips 128. Ashort section 22 ofwashover pipe 10 is lowered over the upper end of the mandrel 12-a and made up to thesection 16. Thedepressing plug 107 is then removed freeing the piston 1G8 causing theslips 128 to set. Thewashover pipe 10 is lowered into the well with additional sections being added to makeup the necessary length. The upper end of the washover pipe (not shown) is then connected to an operating string of pipe and lowered into the well.

Thereafter, during all lowering and manipulation of the apparatus, pressure is applied from pumps at the surface through drilling fluid against the upper end of the mandrel 12-a. A portion of this fluid circulates through thehollow piston rod 110 and longitudinal passage 42-01 in themandrel 12a and a portion of the fluid pressure acts upon thepiston 108 moving the piston i108 and piston rod 1-10 downwardly, overcoming the compression of thespring 144, moving the slip assembly 124- downwardly from theslip expander 122, and retracting theslips 128 so that relative movement between the mandrel 12-1: and thewashover pipe 10 may occur as previously described in the operation of the form of the device illustrated in FIGURES 1 through 8. Upon the fish "43 being .freed as previously described it can be withdrawn from the hole without lifting thewashover pipe 10 relative to it and thus exposing it. This is done by reducing the pump pressure on the fluid in thewashover pipe 10 which will reduce the force of thepiston 10%, and hence theslip assembly 124, on thecoil spring 144 allowing the coil spring 14-4, to urge the slip assembly 124i upwardly setting the slips and engaging the mandrel 12-0! with thewashover pipe 10. Thereafter merely lifting thewashover pipe 10 will remove the mandrel 12-41, thespear 14, and thefish 43.

In the event that thefish 43 is not fireed or in the event that thefish 43 is not freed and also thespear 14 cannot be released from thefish 43 then the application of fluid pressure and setting down on thewashover pipe 10 will retract theslips 128 and allow the device to bemanipulated as described with reference to FIGURES 1 through 8.

While it is preferable to useshear pins 32 with the modified mandrel 12-11 these shear pins may be omitted. If this is done theslips 128 are allowed to set and releasably secure the mandrel 12-a to thewashover pipe 10 during lowering of the apparatus into the well and the securing of thespear 14 to thefish 43. This is done by keeping the drilling fluid pressure on the piston 10S below that necessary to compress thespring 144. When thespear 14 is engaged in thefish 43 the slips 1-28 are released by increasing the pump pressure and setting a 5% down on the washover pipe allowing the washover operations to take place'as previously described.

The present invention, therefore, is well suited to carry out the objects and attain the advantages mentioned as well as others inherent therein. Changes in details and rearrangements of parts will suggest themselves to those skilled in the art and accordingly, it is desired to be limited only by the spirit of the invention as defined by the scope or" the appended claims.

What is claimed is:

l. In an apparatus for recovery of objects lodged in a well the improvement comprising, an elongated washover pipe adapted to be moved in a well, an elongated mandrel in said washover pipe, engaging means connected to the lower end of the mandrel adapted to engage the object in the well, said mandrel including an enlarged diameter portion, releasable connecting means releasably securing the mandrel in the washover pipe, a first J-slot in the enlarged diameter portion of the mandrel below its upper end, a lug on the inner wall of the washover pipe adapted to be slidably received in said first J-slot, a second J-slot in the mandrel below the enlarged diameter portion of said mandrel, and a lug connected to said engaging means and adapted to be slidably received in said second .l-slot, and shearable means releasably securing the engaging means to the mandrel.

2. In an apparatus for recovering lodged objects in a well having an elongated washover pipe adapted to be moved in a well, an elongated mandrel in said washover pipe, said mandrel including an enlarged diameter portion, and engaging means connected to the lower end of the mandrel adapted to engage the object in the well, said engaging means having upwardly directed slips so constructed and arranged so as to engage said object while under an upwards stress, the improvement comprising, a first J-slot in the enlarged diameter portion of the mandrel below its upper end, a first lug on the inner wall of the washover pipe adapted to be slidably received in said J-slot, first shearable means releasably securing the mandrel in the washover pipe, a second J-slot in the mandrel below the enlarged diameter portion, a second lug connected to the engaging means and adapted to be slidably received in said second J-slot, and a second shearable means releasably securing the engaging means to the mandrel, said second shearable means having a higher shearing strength than said first shearable means.

3. In an apparatus for recovery of objects in a well bore, said apparatus including a washover pipe, a mandrel movable in the washover pipe, and engaging means connected to the lower end of the mandrel adapted to engage the object in the well, the improvement comprising, an open ended cylinder at the upper end of the mandrel, a piston slidably mounted in the cylinder, a slip assembly slidably secured to the mandrel, said slip assembly including slips, said mandrel including a vertical slot adjacent the slip assembly, said 'mandrel being tapered adjacent its upper end to form a slip expander adapted to expand the slips into engagement with the washover pipe upon relative movement of the slips towards the slip expander and to release the slips upon relative movement of the slips away from the slip expander, spring means urging the slip assembly toward the slip expander, a rigid connection secured between the piston and the slip assembly through the vertical slot whereby on appli cation of fluid pressure on the piston the slip assembly is moved in one direction retracting the slips.

4. In an apparatus for recovery of objects in a well bore said apparatus including a washover pipe, a mandrel movable in the washover pipe, and en aging means con nected to the lower end of the mandrel adapted to engage the object in the welLthe improvement comprising, an open ended cylinder at the upper end of the mandrel, a piston slidably mounted in the cylinder, a slip assembly slidably secured to the mandrel, said slip assembly ineluding slips, said mandrel including an opening in communication with said open ended cylinder and including a vertical slot adjacent the slip assembly, said mandrel being tapered adjacent its upper end to form a slip expander adapted to expand the slips into engagement with the washover pipe upon relative movement of the slips towards the slip expander and to release the slips upon relative movement of the slips away from the slip expander, spring means urging the slip assembly toward the slip expander, a piston rod secured to the piston and slidably movable in the mandrel opening, and a pin connecting the piston rod to the slip assembly through the vertical slot whereby application of fluid pressure to the piston moves the piston and slip assembly in a direction retracting the slips.

5. The improvement ofclaim 4 including a fluid passageway in the mandrel communicating with a fluid passageway in the piston and piston rod.

6. An apparatus for recovery of objects lodged in the well bore the improvement comprising, an elongated washover pipe adapted to be moved in the well, an elongated mandrel in said washover pipe, said mandrel including an enlarged diameter portion, shearable means securing the mandrel in the washover pipe, at least one J-slot in the enlarged diameter portion of the mandrel below its upper end, said J-slot including a first vertical slot open at the lower end of the enlarged diameter portion, a transverse slot communicating with the first vertical slot, and a second vertical slot communicating with the transverse slot and enclosed at its lower end, an open ended cylinder at the upper end of the mandrel, a piston slidably received in the cylinder, a slip assembly slidably secured to the mandrel, said slip assembly including slips, said mandrel being tapered adjacent its upper end to form a slip expander and adapted to expand the slips into engagement with the washover pipe upon relative movement of the slips toward the slip expander and to release the slips upon relative movement of the slips away from the slip expander, spring means urging the slip assembly toward the slip expander, said mandrel including an opening in communication with the open ended cylinder and including a vertical slot through the mandrel adjacent the slip assembly, a piston rod secured to the piston slidably received in the mandrel opening, a pin connecting the piston rod to the slip assembly through the vertical slot, and engaging means secured to the lower end of the mandrel adapted to engage the object in the Well.

7. The invention of claim 6 including :a fluid passageway extending longitudinally through the mandrel, the piston rod, and the .piston communicating with the washover pipe at the upper end of the mandrel and approximate the lower end of the mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,327,503 Coberly Aug. 24, 1943 2,650,664 Sorensen Sept. 1, 1953 2,762,438 Naylor Sept. 11, 1956 2,804,151 Le Bus Aug. 27, 1957 2,804,927 Hall Sept. 3, 1957 2,817,555 Le Bus Dec. 24, 1957 2,832,423 Hall Apr. 29, 1958 2,869,644 Brown Jan. 20, 1959

Claims (2)

1. IN AN APPARATUS FOR RECOVERY OF OBJECTS LODGED IN A WELL THE IMPROVEMENT COMPRISING, AN ELONGATED WASHOVER PIPE ADAPTED TO BE MOVED IN A WELL, AN ELONGATED MANDREL IN SAID WASHOVER PIPE, ENGAGING MEANS CONNECTED TO THE LOWER END OF THE MANDREL ADAPTED TO ENGAGED THE OBJECT IN THE WELL, SAID MANDREL INCLUDING AN ENLARGED DIAMETER PORTION, RELEASABLE CONNECTING MEANS RELEASABLY SECURING THE MANDREL IN THE WASHOVER PIPE, A FIRST J-SLOT IN THE ENLARGED DIAMETER PORTION OF THE MANDREL BELOW ITS UPPER END, A LUG ON THE INNER WALL OF THE WASHOVER PIPE ADAPTED TO BE SLIDABLY RECEIVED IN SAID FIRST J-SLOT, A SECOND J-SLOT IN THE MANDREL BELOW THE ENLARGED DIAMETER PORTION OF SAID MANDREL, AND A LUG CONNECTED TO SAID ENGAGING MEANS AND ADAPTED TO BE SLIDABLY RECEIVED IN SAID SECOND J-SLOT, AND SHEARABLE MEANS RELEASABLY SECURING THE ENGAGING MEANS TO THE MANDREL.

3. IN AN APPARATUS FOR RECOVERY OF OBJECTS IN A WELL BORE, SAID APPARATUS INCLUDING A WASHOVER PIPE, A MANDREL MOVABLE IN THE WASHOVER PIPE, AND ENGAGING MEANS CONNECTED TO THE LOWER END OF THE MANDREL ADAPTED TO ENGAGE THE OBJECT IN THE WELL, THE IMPROVEMENT COMPRISING, AN OPEN ENDED CYLINDER AT THE UPPER END OF THE MANDREL, A PISTON SLIDABLY MOUNTED IN THE CYLINDER, A SLIP ASSEMBLY SLIDABLY SECURED TO THE MANDREL, SAID SLIP ASSEMBLY INCLUDING SLIPS, SAID MANDREL INCLUDING A VERTICAL SLOT ADJACENT THE SLIP ASSEMBLY, SAID MANDREL BEING TAPERED ADJACENT ITS UPPER END TO FORM A SLIP EXPANDER ADAPTED TO EXPAND THE SLIPS INTO ENGAGEMENT WITH THE WASHOVER PIPE UPON RELATIVE MOVEMENT OF THE SLIPS TOWARDS THE SLIP EXPANDER AND TO RELEASE THE SLIPS UPON RELATIVE MOVEMENT OF THE SLIPS AWAY FROM THE SLIP EXPANDER, SPRING MEANS URGING THE SLIP ASSEMBLY TOWARD THE SLIP EXPANDER, A RIGID CONNECTION SECURED BETWEEN THE PISTON AND THE SLIP ASSEMBLY THROUGH THE VERTICAL SLOT WHEREBY ON APPLICATION OF FLUID PRESSURE ON THE PISTON THE SLIP ASSEMBLY IS MOVED IN ONE DIRECTION RETRACTING THE SLIPS.

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