US2913052A - Liner set tool - Google Patents

Description

B. G. HARMON 2,913,052

LINERsE'rTooL 2 Sheets-Sheet 1 Nov. 17, 1959 Filed July 5, 1956- NOV. 17, '1959 B, Q HARMQN 2,913,052

' LINER SET Toor.

Filed I uly 5, 1956 2 Sheets-Sheet 2 @g4 535' @Q6 j States Patent 2,913,052 LINER SET TooL lill G. Harmon, Carini, Ill., assignor to Engineered Gronting Service, Evansville, Ind., a partnership Application July s, 1956, serial No. l596,111 4 claims. (c1. y16s- 144) The present invention relates to the general ield of oil well equipment. More specifically the invention contemplates a tool for setting a liner in a well. The invention is particularly useful in setting a liner in an extension of a hole in which the casing has already been set.

Quite often after an oil eld has been drilled in and produced, additional geological information is obtained which makes it desirable to drill deeper, through existing wells, to a secondary oil bearing strata. To complete the well, a secondary casing, known as a liner, must be cemented into the secondary drilling. To deliver the cement into the area between the walls of the secondary drilling and the liner, production or other tubing is usually connected to a shoe at the bottom of the liner.

After the cernenting job has been completed, it then becomes necessary to withdraw the production tubing from the well and drill out the shoe before producing. Several techniques have been developed for separating the production tubing from the shoe. Some involve hooks which are jiggled loose. Others use trick couplers which are backed oi to loosen. Almost invariably these various techniques and mechanisms have operational difficulties when even.the most skilled 'and experienced operators are employed.

l The general object of the present invention is to provide an oil-Well liner tool which is simple to operate and insures a complete release.

A more detailed object of the invention is to furnish a wellliner set tool which is controlled and released by hydraulic pressure and consequently subject to accurate control from the well head.

Still another object of the invention is to provide a well liner settool which is inexpensive to construct from standard shapes and-sizes of materials.

Further objects and advantages of the present invention will become apparent as the following description of. an illustrative embodiment proceeds taken in conjunction with vthe descriptive drawings in which:

Figure l illustratesin partial broken section the assembled setting tool employed with the liner in the bottom of an extension of'an existing oil well.

Fig. 2 is alongitudinal sectional view in enlarged scale of the. lower portion of the liner set tool shown in Fig. l illustrating the iirst phase of its operation.

Fig. 3 shows the same tool as illustrated in Fig. 2 but after the yports have been opened for operation.

Fig. 4 is an enlarged partial section of the lower portion of the liner set tool illustrating the tension sleeve severance at the initial stage of release.

' Fig. 5 is an enlarged partial section of the lower portion of the liner set tool showing the cementing phase taking place.

Fig. 6 is a partial sectional view in reduced scale of the elements shown in Fig. 4 illustrating the iinal ushing operation after the liner has been cemented in place.

Fig. 7`is a transverse sectional view taken through the tension sleeve portion of the liner set tool along section line 7-7 of Fig. 2.

' terminating at the bottom portion 16 of the well.

sa *ce The heart of the present invention is the use of hydraulic pressure to accomplish all phases ofthe liner set tool operation, `and particularlyto accomplish its release. In Vessencethe invention proceeds from the discovery that av tension member, calculated to part at preselected hydraulic pressures,` may be employed to accomplish the release of the tool in setting the liner.

Although the following`v description relates to a secondary drilling operation, and setting a liner after such a drilling, thegmechanism may be employed inrsetting a liner Whenever desired. Accordingly the invention contemplates settingaliner and is not intended to be limited to the specific operation shown in the drawings and described iny detail.

` Referringnow to Fig. 1, it will be seen that the casing 10 of the original well has been` set in cement 11 liush up against the earthenside Wall 1,2 of the drilling. The secondary bore 14eXtends down to the pay zone area 15 When it is appreciated'that the secondary casing or liner 18 may-be Vset at any depth below the surface, it will be appreciated'thatthe problem of orienting and controlling theliner 18 for cementing into the hole 14 is a diicult one.

After the secondary hole 14 has been drilled, a concrete shoe 1,9 is loweredto the bottom of the well cornmunicating to the well head by means of a string of production tubing 2.0. The` invention resides in the structure employed, to coupleand uncouple the shoe 19 with the string of production tubing 20. Y

Referring-howto Figs. 2 and 3, it will be seen thatthe concrete shoe 19 is encased in a sleeve 2x1 having a plu-r rality of lands 22 and grooves 24'which firmly anchor the concrete to the sleeve 21. The upper portion 2S of the sleeve 21 s threaded'and threadedly engages `the lower portion 26 of the liner 18. In this manner the depth to which the liner 18k penetrates the hole 14 will be largely a function of the depth to which the shoe 19 is permitted to descend.

To couple the shoe 19 with the production tubing 20, a threaded ring 28` is secured in the upper portion 25 of the shoe sleeve 21. The internal portion 29 of the threaded ring 28 is threaded toreceive the tension sleeve 30. The tension sleeve 30is`thread'ed at its lower end 31 for a'threaded engagement with Athe ring 28 thereby coupling the tension sleeve 30with the shoe 19. At its upper end 32 the tension sleeve is similarly threaded to fit a standard sleeve.typethreadedcoupling 34.

Itrwill be appreciated that if the tension sleeve 30 is severed at its narrow neck portion 35, the entireupper assembly including the production tubing 20 may be withdrawn from the inner portion of the liner 18 leaving the shoe 19 andits related elements in place.

A by-pass valve assemblyy 36 is provided with the lower threaded portion 38. to threadedly engage the coupling sleeve 34. 'I'he valve assembly 36 contains a hollow sliding sleeve 39 which is secured in place by meansof shear pins 40 in such amanner that the by-pass sub-'ports 41 are covered.- The sleeve Avalve39.hasfa pair of -0rings 42 at its upper andlowerr portion to'` seal o circulation around itsperiphery. The .fOrings 42-hold the sliding Asleevein place. until the ball 51 is droppedand the pressure raised within thestring to open the bypass sub-ports 41 as Willbe described hereinafter. Y Y

The upper portion of the valve assembly 36 is .threaded internally .toreceivean externally' threaded coupler 45 which in turn is connectedto afsingle-acting packer as'- sembly.46. Thesinglelacting packer cup 48serves :to preventdhe owof` uidp. upwardly through the annulus 4 9 dehned by the inner wal1of--the liner- 1'8 and-the'l outer portion ofthe valve assemblyY 36."

The remaining details of construction will be more fully f y n 2,913,052

, 3 e appreciated as the sequential operation of the tool is set forth. As pointed out above, the liner tool illustrated is employed in a secondary hole 14 drilled through a completed well havinga casing 10 cemented in place. The entire liner assembly is then lowered down the well'supported by the production tubing 20 and-lowered to a predetermined locationto a secondary drilling 14.` In the event that the operation renders it undesirable to lower the shoe 19 directly on to the bottom of the well 16, a liner hanging tool 50 is .employed to fix the liner 18 to the existing casing 10 at a predetermined location. The advantageous use of the present tool will become quite apparent when it is appreciated that the liner hanging tool 50 is released by twisting the liner 18. Such liner hangers are known in the art (see my copending application Serial No. 614,100), and anyhanger tool which locks the casing 10 and liner 18 to each other will suiice. The entire operation of cementing the liner in place, by employing the unique tool of the invention, isV accomplished without any subsequentl twist of the liner 18 after the liner set tool 50 has been engaged.

After the liner 18 has been oriented to its appropriate depth in the secondary drilling 14, the by-pass valve actuating ball 51 is dropped down the tubing Z0 until it sits on theupper shoulderSZ of the sliding valve 39. At this point the pressure of the tiuid within the tubing is raised to place a suiiicient load on the sliding valve to shear the sliding valve support pins 40. This action drops the lower shoulder 52 of the sliding valve 39 on to the internal shoulder 54 of the valve assembly 36 as best illustrated in Fig. 3. This opens the by-pass ports 41 to permit the uid passing down through the tubing to pass outwardly into the annulus 49 defined by the liner set tool periphery and the internal wall 18. The shear pins 40, or their remains, then are forced into the bottom of the hole by the force of gravity augmented by the iiuid ow.

After the operator has assured himself that the tubing is sound by pressure testing at a predetermined testing pressure, the pressure is then raised to approximate the predetermined parting pressure. This pressure exerts a tensile force on the narrow neck 35 of the tension sleeve 30 because the fluid passing through the by-pass ports 41 bears downwardly on the threaded ring 28 and upwardly on the packer element 48. The neck 35 of the tension sleeve 30 is so proportioned that it will separate as shown in Fig. 4. In order to insure that a complete severance at the neck 3S is achieved, a stinger 55 extends from the bottom of the valve assembly 36 and traverses the narrow neck portion 35 of the tension sleeve 30. The stinger 55 also serves to add rigidity to the assembly. A pair of -rings 56 at the bottom of the stinger 55 prevent any uid from passing downwardly into the shoe 19 until after complete severance has been accomplished. Y

Although the cementing operation could be performed prior to severing the tension sleeve 30, most operators prefer to release the liner prior to pumping the cement down the hole to cement the liner in place. Accordingly the operator will raise the string of tubing 20 in order to remove the stringer 55 from the lower portion of the tension sleeve 30 and then pump a slurry of cement down the vtubing Z0. The cement then flows 'down through the hollow central portion S7 of the shoe 19 and passes outwardly through the lateral by-pass ports 58.and downwardly through the lower annulus 59 of the shoe 19. When the total predetermined charge of cement is in place around the liner, the ow of uid may be reversed by pumping the fluid past the single acting packer 48 and down through the annulus 49 on the outside of the string of equipment. The fluid then ows, as shown in Fig. 6, up through the central portion of the stinger 55 and the tubing 20. It will be noted that the check valve 61 in the shoe 19 serves to prevent any excessive pressure on the outside of the shoe 19 from backing cement uid up through the liner 18 as the flushing operation takes place.

4 The ball valve 61 sits in the seat portion 62 of the check valve ring 64 in the bottom of the shoe assembly 19.

After the hole has been flushed to clean out the excess cement, the string of production pipe along the associated valve assembly 36 is removed from the well and the cement foundation 60 is allowed to set. Thereafter the shoe 19 is drilled out with an ordinary drilling tool and the production operation completed. It will be appreciated that in order to facilitate this final drilling out of the shoe 19, the shoe should be formed of a material which can be readily drilled such as concrete, plastic, aluminum and the like, and the various ttings within the shoe of soft materials such as brass and the like.

As pointed out above by using the set tool described, no rotation of the liner 18 takes place after it is lowered into the well. In addition, severance of the tension sleeve permits a clean and positive removal of the string of tubing and associated valve mechanism. The liner hanger 50 may be employed in the event that it is not desired to lower the shoe to the bottom of the hole. On the other hand, the shoe may be lowered to the bottom of the yhole supporting the liner and associated equipment until it is removed. Further, in view of the hydraulic pressures at various levels, various critical operations can be positively determined by the employment of pressure gauges at the well head.

Although particular embodiments of the invention have been shown and described in full here, there is no intention to thereby limit the invention to the details of such embodiments. On the contrary, the intention is to cover all modifications, alternative embodiments, usages and equivalents of the liner set tool as fall within the spirit and scope of the invention, specification, and appended claims.

I claim as my invention:

1. For use on a string of well tubing and associated liner, a liner set tool comprising, in combination, a support, means on the support for attachment to the liner at the lower end of the liner, a tension sleeve, means on the lower end of the string 0f tubing for slidable sealed engagement with the tension sleeve, means onthe support for attaching the tension sleeve within the liner thereby defining a tubing-liner annulus closed at its lower end, said tubing having a port therein, valve means on the tubing adjacent the port for selectively diverting the fluid pressure within the tubing to the tubing-liner annulus, and a packer element within the tubing-liner annulus and above the valve means oriented so that when the pressure is diverted into the tubing-liner annulus the packer element prevents upward flowrof the fluid thereby tensioning the tension sleeve to its parting load.

2. A liner set tool for setting a liner having a hollow central bore through which a string of tubing may be extended comprising, in combination, a liner support coupled to the liner at the lower end thereof, a tubular tension sleeve secured to the lower end of the string of tubing and to the liner support and defining anannulus between its outer surface and the inner surface of the liner, a tubular extension of the string of tubing, said extension having sealing means for a sliding sealed relationship with the tubular tension sleeve, a packer element sealing the annulus defined by the outer portion of the string of tubing and inner bore of the liner against an upward uid flow, said tubing having port means therein below said packer element, and valve means slidable on the string of tubing adjacent said port means for opening the same thereby selectively diverting fluid pressure from within the tubing to the annulus defined by the liner and tubing in that portion below the packer element and above the support, the valve means being located below the packer element, the tension sleeve being structurally reduced so that increase in the pressure of the fluid diverted by the valve means will cause the tensionV sleeve to part at the reduced portion thereby pmlitting the tubing to be withdrawn from the well.

3. A liner set tool of the character defined in claim 2 above, in which the valve means is characterized by an inner sliding sleeve within said tubing having an annular shoulder at its upper end, the port means being constituted as by-pass ports, shear pins positioning the sleeve to cover the ports, the shoulder in the sleeve being proportioned to engage a ball dropped down the tubing thereby permitting hydraulic pressure to shear the pins and open the by-pass ports.

4. A liner set tool for setting a liner having a hollow central bore through which a string of tubing is extended comprising, in combination, a liner shoe having a central conduit, means on the shoe for lockingly engaging the liner, a tension sleeve secured to the shoe, means coupling the tension sleeve with the string of tubing, a packer element sealing the annulus defined by the outer portion of the string of tubing and inner bore of the liner, said tubing having a port therein below said packer element, valve means on the string of ltubing adjacent said port for selectively diverting uid pressure from within the tubing to the annulus dened by the liner and tubing, a hollow stinger extending downwardly from the valve means into the tension sleeve, the tension sleeve being structurally reduced so that increase in the pressure of the fluid diverted by the valve means will cause the tension sleeve to part at the reduced portion thereby permitting the tubing to be withdrawn from the well leaving only the shoe and liner.

References Cited in the le of this patent UNITED STATES PATENTS 1,842,107 Lytle Jan. 19, 1932 2,315,931 Burt et al. Apr. 6, 1943 2,436,525 ODonnell Feb. 24, 1948 2,621,742 Brown Dec. 16, 1952 2,653,666 Baker Sept. 29, 1953

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