US3059699A

US3059699A - Well packer and well production apparatus

Info

Publication number: US3059699A
Application number: US729172A
Authority: US
Inventors: Cicero C Brown
Original assignee: Brown Oil Tools Inc
Current assignee: Baker Hughes Holdings LLC
Priority date: 1958-04-17
Filing date: 1958-04-17
Publication date: 1962-10-23
Anticipated expiration: 1979-10-23

Description

Oct. 23, 1962 v c. c. BROWN 3,059,699

WELL PACKER AND WELL PRODUCTION APPARATUS Filed April 17, 1958 2 Sheets-Sheet 1 C/cero C. B/own INVENTOR.

BY K

ATTORNEY Oct. 23, 1962 c. c. BROWN WELL PAC'KER AND WELL PRODUCTION APPARATUS Filed April 17, 1958 2 Sheets-Sheet 2 (were C. Bro vv/7 3,059,699 Patented Get. 23, 1962 3,059,699 WELL PAKIKER AND WELL PR'SDUCTHQN AFPARATUS Cicero C. Brown, Brown i] Tools, Inc., R9. Box 19236, Houston, Tex. Fiied Apr. 17, 1953, Ser. No. 729,172 15 Claims. (Cl. 166187) This invention relates to well packers and particularly to a hydraulic pressure-actuated packer and to a well production apparatus employing such packers.

A primary object of this invention is to provide an improved form of well packer which is set by hydraulic pressure and released by rotation of the pipe string on which it is mounted.

A principal object is to provide a form of packer in which the expansion of a resilient packer member is effected by the relative movement of a cylinder and piston elements secured respectively to the packer member and to the operating string in response to fluid pressure supplied from the interior of the operating string to the interior of the cylinder to compress or set the packer.

An additional object is to provide a packer employing a compressible resilient packing element operatively connected to an actuating head comprising a cylinder and a piston enclosed within the cylinder, relatively movable in response to hydraulic pressure introduced between the piston and the cylinder from the interior of an operating pipe string, the piston having port means for passage of hydraulic fluid therethrough from the pipe string, said port means being provided With check valve means for retaining the pressure introduced into the cylinder.

A further object is to provide a production apparatus for wells having a plurality of producing formations at different elevations, the apparatus comprising the combination with a pipe string insertible in the well bore, of a plurality of the packers in accordance with this invention mounted on the pipe string in positions adapted to isolate the producing formations from one another, and a plurality of sleeve valves mounted in the bore of the pipe string between the several packers and opposite the respective producing formations, said sleeve valves being arranged to be selectively opened or closed to permit flow of fluids from selected earth formations through the well string.

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

In the drawing:

FIG. 1 is a view showing a well intersecting a plurality of fluid-producing formations at difierent elevations and having positioned therein production apparatus in accordance with this invention for selectively producing fluids from the several formations.

FIG. 2 is a longitudinal, partly sectional view of a well packer in accordance with this invention, the parts being shown in the unset or inactive position, as when being inserted in a well;

FIG. 3 is a view similar to FIG. 2, showing the parts of the packer in the set position; and

with a section of external threads 12 received in the internally threaded bore of an adapter 13 by which the lower end of mandrel 10 maybe connected into pipe string S. The upper end of adapter 13 forms an upwardly facing shoulder 15 about the lower end of body 10 and is adapted to provide a supporting stop for a collar 16, which, in turn, forms a base or support for a flexible, resilient annular seal element 17. The latter is provided with upper and lower

lead end rings

18 and 19, respectively, lower end ring 19' being interposed between the lower end of seal element 17 and collar 16. Seal element 17 and

end rings

18 and 19 are slidably positioned on body 10 so that when downward compression is applied against upper end ring 18, seal element 17 will be compressed against collar 16 and the resulting compression will expand the seal element radially outwardly, as is well understood in this art, to form a fluidtight seal with the surrounding well wall.

Disposed above upper end ring 18 and slidably surrounding mandrel 10 is a cylinder 20 having an enlarged bore 24, the lower end of which is closed by a head 21 which abuts upper end ring 18. Head 21 is provided with a central opening 22 to slidably receive mandrel 10. A packing ring 23, such as a conventional O-ring, is disposed in the wall of opening 22 to form a fluid-tight slidable seal between the cylinder head and the exterior of mandrel 1t). Bore 24 is open at its upper end and adapted to slidably receive a tubular piston 25, having a central bore 27 through which mandrel 10 extends. The upper end of piston 25 projects above the open end of cylinder 20 and is provided with an internally threaded socket 26 for connecting the piston to an adapter 28 by which the piston may be connected into pipe string S. Below socket 26, the bore 27 of piston 25 is provided with a section of left-hand threads 29 which are adapted to mesh with mating threads 30 provided on the exterior of mandrel 10 adjacent its upper end. The section of threads 29 is made substantially longer than the section of threads 30, and below the lower end of threads 29, bore 27 is provided with an upwardly facing shoulder 31 adapted to engage the lowermost thread 30 to limit upward movement of piston 25 relative to mandrel 10' for purposes to be more fully described hereinafter. A threaded shear pin 32 of pre-determined breaking strength, is mounted in the wall of cylinder 20 near its upper end to project into a threaded socket 33 provided in the exterior of piston 25 at a point which permits the shear pin to lock the piston to the cylinder, and thence to the pipe string, when the piston is in a substantially fully inserted position within the cylinder. The connection between cylinder 20 and piston 25 formed by shear pin 32 initially prevents relative longitudinal and rotational movement between cylinder 20, piston 25 and pipe string S, and serves to hold cylinder 20 in non-compressing relation to seal element 17.

A circumferential groove 34 is cut in the exterior of piston 25 near its inner end and is adapted to receive annular sleeve 35, constructed of rubber or similar flexible, resilient material. Sleeve 35 has a length such as to fit freely in groove 34 and has a cylindrical bore 36 of a normal diameter such as to seat tightly against the bottom of groove 34. The bottom of groove 34 is countersunk at 37 to receive a split metal ring 38 adapted to form a support backing for sleeve 35. A port 39 extends radially through the wall of piston 25 to provide fluid communication between the bore of piston 25 and the bottom of groove 34 through aregistering opening 40 provided in ring 38. A radial port 41 is provided through the wall of mandrel 10 positioned to be in registration with port 39 to thereby provide fluid communication between bore 11 of mandrel 10 and groove 34 through the 3 intervening passageway formed by port 39 and opening 40.

Sleeve 35 constitutes a normally closed, outwardly opening check valve adapted to control communication between bore 11 of the mandrel and bore 24 of cylinder 29. Thus, when fluid pressure in bore 11 exceeds that in bore 24, this differential pressure will act to force sleeve 35 outwardly away from the bottom of groove 34 sufiiciently to allow pressure fluid to flow through ports 41-, 39 and 40 and pass around the ends of sleeve 35 to enter bore 24. Conversely, a pressure differential in the op posite direction will compress sleeve 35 tightly against the bottom of groove 34 and prevent back-flow of pressure fluid and thereby serve to trap whatever pressure has been introduced into bore 24.

An annular packing 42, such as a conventional O-ring, is positioned about the exterior of piston 25 slightly above groove 34 to form a slidable fluid-tight seal between the piston and the wall of cylinder 29. A second annular packing 43, such as a conventional O-ring, is positioned in bore 27 at a point below port 39 to form a slidable fluid-tight seal between the piston and the exterior of mandrel 10. It will be seen that when piston 25 and mandrel are in the relative positions shown in FIGS. 2 and 3,

packings

23, 42 and 43, in cooperation with sleeve 35, will act to trap between these packings any fluid pressure which may have been admitted into cylinder 20. The portion of bore 24 of the cylinder extending between the longitudinally spaced

packings

23 and 42 forms a longitudinally extendible pressure chamber into which pressure fluid may be introduced through the conduit means comprising the

ports

39, 40 and 41 for urging the cylinder into axially compressive engagement with seal element 17. An annular packing 44 is provided between adapter 28 and socket 26 to seal between these connection elements.

Packer P, constructed as above described, is designed to operate in the following manner: When initially installed in pipe string S, the parts of the packer will be in the position illustrated in FIG. 2, in which piston will be inserted in cylinder 20 and secured thereto by means of shear pin 32;

ports

39 and 41 will be in registration and packing '43 will be disposed below the passage formed by the registering ports 39 and '41. When sufiicient fluid pressure is developed in bore 11 of the mandrel, this pressure will be exerted through

ports

41 and 39 against the inner surface 36 of sleeve valve and will force the latter away from opening sufliciently to allow the pressure to enter bore 24 of the cylinder. This pressure will,

as previously noted, be trapped between

packings

23 and 42 and will tend to urge the cylinder and piston apart. When sufficient pressure is thus introduced into bore 24 of the cylinder to exceed the breaking strength of shear pin 32, the latter will part (FIG. 3) and the pressure will then act to force the piston and cylinder apart. Since the piston will be connected to the pipe string, it will be held against movement relative thereto, and the pressure entering bore 24 will force cylinder 20 downwardly, thereby compressing seal element 17 against collar 16 and expanding the packer radially into sealing engagement with the surrounding well wall to seal off the space between pipe string S and a liner L forming the wall of the well. This set position of the packer is illustrated in FIG. 3.

To release the packer, the pipe string will be rotated in the right-hand direction.

Threads

29 and 30 being left-hand threads, the right-hand rotation of the pipe string will cause piston 25 to move upwardly relative to mandrel 10. A slight upward pull may be applied to the pipe string to aid this movement. The upward movement of piston 25 relative to mandrel 10 will move the lower end of the piston upwardly until packing 43 has moved above port 41, whereupon pressure previously trapped between

packings

23 and 42 will escape through port 41 into bore 11 of the mandrel. Release of pressure from the interior of the bore.

of the cylinder will allow seal element 17 to retract by reason of its natural resilience and thereby release its sealing engagement with the wall of the well. Rotation of the operating string may be continued until shoulder 31 comes up against the lowermost thread 3%, whereupon further rotation will act to rotate the cylinder as well as all of the operating string below this packer.

Where additional packers P are mounted on the pipe string below the uppermost packer l, the engagement of shoulder 31 with the thread 39 of the uppermost packer will permit the continued rotation of the pipe string to be transmitted to the next lower packer where this rotation will become effective to release the next lower packer in the same manner as previously described. Thus, any number of packers, such as packer P, may be mounted on the pipe string and may be released in succession by rotation from the top in the manner described.

Referring now to FIG. 1, there is shown an apparatus employing two packers P and P of the construction previously described, in an assembly to be inserted in a well W, having a plurality of fluid producing formations F F and F at different elevations along the well bore. The apparatus is constructed and arranged to permit pro duction of fluids from selected ones of the formations. As illustrated, well W is equipped with the liner L having a series of perforations H H and H opposite the respective formations F F and F Pipe string S has mounted thereon the packers P and P one at a point between formations F and F and the other at a point between formations F and F whereby to isolate each of the formations from the others when the packers have been set as shown. Above packer P and opposite perforations H pipe string S is fitted with a sleeve type valve, designated generally V comprising tubular valve casing C adapted to form a part of pipe string S. Casing C is provided with ports G through the wall thereof to provide communication between the interior of valve casing C and the bore of liner L. A valve sleeve V is longitudinally slidable in the bore of easing C relative to ports G to control the flow of fluid through ports G The specific details and the particular form of valve V do not form a part of this invention, as such sleeve valves are entirely conventional and their construction and operation will be fully understood by those skilled in this art. Valves V and V identical in construction to valve V are positioned in pipe string S, respectively, between packers P and P and below the latter. Thus the valves V V and V are positioned to control communication between the bore of the pipe string and the respective earth formations F F and F At its lower end pipe string S is fitted with a tubular tail piece section T having an annular upwardly facing seat A in the bore thereof to receive a plug Q, which is adapted to be dropped through the bore of pipe string S in order to close the lower end Plug Q carries a set of anchor slips K which anchor the plug against upward displacement from seat A.

The apparatus illustrated in FIG. 1 is employed in the following manner: Packers P and P and valves V V and V will all be installed in the relative positions as illustrated in FIG. 1 and the apparatus will then be lowered into the well and into liner L to a point at which the packers and the valves will be in the positions relative to the several producing formations as illustrated.

' When the apparatus is first introduced into the well, plug Q will not be in place, so that when the apparatus has been lowered to the desired position in the liner, fluid circulation may be set up through the bore of the pipe string and thence upwardly outside the pipe string through the bore of the liner to the surface to thereby wash the well preparatory to putting it into production. Thereafter, plug Q will be lowered through the bore of the pipe string to rest upon seat A in order to close off the lower end of the bore of the pipe string. Valves V V and V may all be in their closed positions during the washing opera tion. After the plug is in place, hydraulic fluid, such as water or oil, will be pumped into the bore of pipe string S and its pressure built up to such a point as will set packers P and P in the manner previously described, and thereby seal off the bore of liner L between the perforations communicating with formations F F and F as illustrated. When this has occurred, the pressure trapped in cylinders 24 of the respective packers will remain therein and continue to hold packers P and P in their expanded or sealing positions until subsequently released. After all the packers are set, a valve-actuating tool D, of suitable and generally conventional construction, adapted to move the valve sleeves longitudinally in the valve casings, will be run into the well on a Wire line B and manipulated in a suitable and generally conventional manner to move one of the valve sleeves to the valve-opening position. The particular sleeve valve which thus may be opened may be any one of the several valves and will ordinarily be the lowermost valve in the string. Upon opening the valve, actuating tool D will be Withdrawn from the well and fluids from the related earth formation thus placed into communication with the pipe string will flow into the pipe string and thence to the surface. Production of fluid from the selected formation may thus be continued until that formation is exhausted, the other valves being kept closed in the meantime and the packers being maintained in the expanded position by the pressure fluid which had been trapped in their respective cylinders. To initiate production from .another formation, tool D may be run back into the well and manipulated to close the previously-opened valve and to then open another of the valves in the string to thereby place its corresponding formation in production.

Thus, the apparatus heretofore described may be used to successively produce a number of fluid-producing formations until all have been exhausted. It will be understood, of course, that, conditions permitting, more than one earth formation may be produced at the same time.

When production from all of the several formations has been exhausted, the apparatus may be removed from the well simply by rotating pipe string S to retract pistons 25 in their respective cylinders 20, in the manner previously described, to thereby successively release the several packers from their sealing engagement with liner L. When all of the packers have been thus released, the entire string may be withdrawn from the Well.

Instead of employing-a tail pipe T having an open bore which may then be closed by means of plug Q, the lower end of the pipe string may be closed by a permanent closure and the apparatus assembly may be run into the well with one or more of the sleeve valves in the open position so that washing of the well may be conducted the operating pipe string, and that the invention further provides a simple apparatus employing a plurality of the described packers'in combination with relatively simple sleeve valves to provide a means for selectively producing formation fluids from a plurality of earth formations with-.

out requiring the removal of the pipe string or any part thereof when necessary or desirable to switch production from one formation to another.

:It will be understood that various modifications and variations may be made in the details of the illustrative.

embodiments within the scope of the appended claims, but

without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is: l. A hydraulic pressure-actuated Well packer, comprising, a tubular mandrel adapted for connection into a well...

6 pipe string, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, a tubular piston member disposed about the upper end of the mandrel and slidably extending into the cylinder, means for connecting the upper end of the piston member to the pipe string, thread connection means connecting the piston member to the mandrel for effecting relative longitudinal movement therebetween in response to relative rotation therebetween, longitudinally spaced seal means positioned respectively between the cylinder and the mandrel and between the cylinder and the piston member to define a pressure chamber in the cylinder between the seal means, conduit means extending through the mandrel and piston member for introducing pressure fluid from the interior of the mandrel into said chamber to urge said cylinder into axially compressive engagement with said seal element to expand the seal element, check valve means in the piston member controlling the conduit means to prevent back-flow of pressure fluid from the chamber, said piston member being movable by rotation of the pipe string relative to the mandrel to open said conduit to permit back-flow of said pressure fluid whereby to retract said seal element, and releasable connector means initially securing said cylinder to said piston member in non-compressing position relative to .oneof said abutment members being fixed to the mandrel and the other abutment member being movable longitudinally relative to the mandrel, said other abutment member comprising a cylinder surrounding the mandrel, conduit means for conducting pressure fluid from the interior of the mandrel into the cylinder to actuate the latter and set the packing element, and control means in the cylinder cooperating with the conduit means to normally retain .said pressure fluid in the cylinder when in one position whereby to maintain the packing element in set position,

said control means including means forming a rotative connection between the mandrel and the pipe string whereby relative rotation between the well pipe string and the mandrel will move the control means to another posi- .tion relieving the fluid pressure on the cylinder and thereby unsetting the packing element.

3. A well packer, comprising, a tubular mandrel releasably connected to a well pipe string to form a part thereof, an annular flexible packing element surrounding the mandrel, a pair of abutment members mounted on the mandrel confining opposite ends of the packing element, one of said abutment members being fixed to the mandrel and the other abutment member being movable longitudinally relative to the mandrel, said other abutment member comprising a cylinder surrounding the mandrel, conduit means for conducting pressure fluid from the interior of the mandrel into the cylinder to actuate the latter and set the packing element, control means in the cylinder cooperating with the conduit means to normally retain said pressure fluid in the cylinder when in one position whereby to maintain the packing element in set position, said control means including a sleeve valve carried by the pipe string and having a screw connection to the mandrel operable by relative rotation between the well pipe string and the mandrel to move the control means to another positon relieving the fluid pressure on the cylinder and thereby unset the packing element.

4. A well packer, comprising, a tubular mandrel releasably connected to a Well pipe string to form a part thereof, an annular flexible packing element surrounding the mandrel, a pair of abutment members mounted on the mandrel confining opposite ends of the packing element, one of said abutment members being fixed to the mandrel and the other abutment member being movable longitudinally relative to the mandrel, said other abutment member comprising a cylinder surrounding the mandrel, conduit means for conducting pressure fluid from the interior of the mandrel into the cylinder to actuate the latter and set the packing element, and check valve means carried by the pipe string cooperating with the conduit means to retain said pressure fluid in the cylinder when in one position whereby to maintain the packing element in set position, said check valve means having a threaded connection to the mandrel whereby relative rotation between the well pipe string and the mandrel will move the check valve means to another position to relieve the fluid pressure on the cylinder and thereby unset the packing element.

5. A well packer, comprising, a tubular mandrel connectible to a well pipe string to form a part thereof, an annular flexible packing element surrounding the mandrel, a pair of abutment members mounted on the mandrel confining opposite ends of the packing element, one

of said abutment members being fixed to the mandrel and the other abutment member being movable longitudinally relative to the mandrel, said other abutment member comprising a cylinder surrounding the mandrel, conduit means for conducting pressure fluid from the interior of the mandrel into the cylinder to actuate the latter to expand and set the packing element, and means in the cylinder cooperating with the mandrel to normally maintain the cylinder in actuated position relative to the packing element whereby to maintain the packing element in set position, said last-mentioned means including threaded means connecting the pipe string to the mandrel operable by relative rotation between the well pipe string and the mandrel to release the cylinder for movement to a position to permit unsetting of the packing element.

6. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder surrounding the mandrel and slidable longitudinally thereof into axially compressive engagement with the seal element in response to hydraulic pressure introduced into the cylinder from the bore of the mandrel to expand said seal element, port means through the wall of the mandrel providing fluid pressure communication between the bore of the mandrel and the interior of the cylinder, means forming a rotative connection between the pipe string and the mandrel, valve means carried by the pipe string normally controlling the port means operable to retain the hydraulic pressure in the cylinder and movable relative to the port means by rotation of the pipe string relative to the mandrel to release the hydraulic pressure from the cylinder to permit contraction of said seal element.

7. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, conduit means through the Wall of the mandrel for introducing hydraulic pressure fluid from the bore of the mandrel into the interior of said cylinder to urge the cylinder into said compressive engagement with the seal element to expand the seal element, means forming a rotative connection between the pipe string and the mandrel, valve means carried by the pipe string controlling said conduit means to normally retain the hydraulic pressure in said n (It cylinder and movable relative to the conduit means by rotation of the pipe string relative to the mandrel to release the hydraulic pressure from the cylinder to permit contraction of said seal element.

8. A hydraulic pressure-actuated well packer, com prising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement With the seal element, conduit means through the wall of the mandrel for introducing hydraulic pressure fluid from the bore of the mandrel into the interior of said cylinder to urge said cylinder into said compressive engagement with the seal element to expand the seal element, means forming a rotative connection between the pipe string and the mandrel, valve means carried by the last-mentioned means controlling said conduit means to normally retain hydraulic pressure in said cylinder and movable relative to the conduit means by rotation of the pipe string relative to the mandrel to release said hydraulic pressure from the cylinder to permit contraction of said seal element, and releasable means initially securing said cylinder relative to the mandrel in non-compressive position relative to said seal element.

9. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, conduit means through the wall of the mandrel for introducing hydraulic pressure fluid from the bore of the mandrel into the interior of said cylinder to urge said cylinder into said compressive engagement with the seal element to expand the seal element, means arranged in the conduit means and operatively connected to the pipe string to retain said pressure fluid in said cylinder and to prevent back-flow of pressure fluid through said conduit means including means forming a rotative connection between the pipe string and the mandrel, said back-flow preventing means being movable relative to the conduit means by rotation of the pipe string relative to the mandrel to a position adapted to release the pressure fluid from said cylinder to permit retraction of the seal element.

10. A hydraulic pressure-actuated Well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, conduit means through the wall of the mandrel for introducing hydraulic pressure fluid from the bore of the mandrel into the interior of said cylinder to urge said cylinder into said compressive engagement with the seal element to expand the seal element, means forming a rotative connection between the pipe string and the mandrel including means arranged to control the conduit means to prevent back-flow of pressure fluid through said conduit means, the back-flow preventing means being movable relative to the conduit means by rotation of the pipe string relative to the mandrel to a position adapted to release said pressure fluid from the cylinder to permit retraction of the seal element, and releasable means initially securing said cylinder relative to said mandrel in non-compressing position relative to said seal element, said last-mentioned means being releasable by predetermined fluid pressure in said cylinder.

11. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, longitudinally spaced seal means positioned between the cylinder and the mandrel to define a pressure chamber therebetween, conduit means extending through the wall of the mandrel into communication with the interior of said chamber for introducing pressure fluid from the interior of the mandrel into said chamber to urge said cylinder into said axially compressive engagement with said seal element, means forming a rotative connection between the pipe string and the mandrel, and check valve means carried by said pipe string within the cylinder controlling said conduit means to retain said pressure fluid in said cylinder and to prevent back-flow of pressure fluid through said conduit means, said check valve means being movable relative to the conduit means by rotation of the pipe string relative to the mandrel to a position adapted to release the pressure fluid from the cylinder.

12. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a Well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, a tubular cylinder surrounding said mandrel and slidable longitudinally thereof into and out of axially compressive engagement with the seal element, longitudinally spaced seal means positioned between the cylinder and the mandrel to define a pressure chamber therebetween, conduit means extending through the wall of the mandrel into communication with the interior of said chamber for introducing pressure fluid from the interior of the mandrel into said chamber to urge said cylinder into said axially compressive engagement with said seal element, means forming a rotative connection between the pipe string and the mandrel, check valve means on the pipe string within the cylinder controlling said conduit means to retain said pressure fluid in said cylinder and to prevent back-flow of pressure fluid therethrough, releasable means initially securing said cylinder relative to the mandrel in noncompressing position relative to the seal element, said releasable means comprising a shear pin breakable upon attainment of a predetermined pressure in said chamber, said check valve means being movable relative to the conduit means by rotation of the pipe string relative to the mandrel to a position adapted to release the pressure fluid from the cylinder to permit retraction of said seal element.

13. Production apparatus for wells intersecting a plurality of vertically spaced-apart fluid-producing earth formations, comprising in combination with a pipe string closed at its lower end and disposed in the well to extend through the several formations, a plurality of hydraulic pressure expansible packers mounted on the pipe string at points between the several said earth formations, each of said packers including a packer body with a resilient seal element expandible by hydraulic pressure and conduit means for supplying and hydraulic pressure from the bore of the pipe string to actuate said seal elements to seal off the well bore between the several earth formations, port means in the pipe string at levels to provide fiuid communication between the pipe string and the several sealedoff portions of the well bore, and separate sleeve valve means mounted in the pipe string to control the respective port means and selectively operable to place said pipe string in fluid communication with selected ones of said earth formations, each of said packers including cooperating relatively rotative means connecting the pipe string to the packer body operable by rotative of the pipe string relative to the packer to permit retraction of the seal elements from their sealing engagement with the well wall, said last-mentioned means having means limiting said relative rotations thereby transmit said rotations successively to the several packers.

14. A hydraulic pressure-actuated well packer, comprising, a tubular mandrel connectible into a well pipe string to form a part thereof, an annular resilient seal element disposed about the mandrel and arranged thereon to be radially expandible by axial compression, means including a tubular cylinder slidable longitudinally of the mandrel into axially compressive engagement with the seal element in response to hydraulic pressure introduced into the cylinder from the bore of the mandrel to expand said seal element, conduit means providing hydraulic pressure communication between said mandrel and said cylinder, and valve means carried by the pipe string and movable thereby relative to the mandrel for controlling said conduit means, said valve means being operable when in one position to admit and retain the hydraulic pressure in the cylinder and when moved to a second position to release and hydraulic pressure to thereby permit retraction of said seal element.

15. Production apparatus for wells intersecting a plurality of verically spaced-apart fluid-producing earth formations, comprising in combination with a pipe string extending into the well through the sever-a1 earth formations and closed at its lower end, a plurality of hydraulic pressure-actuated packers including packer bodies mounted on the pipe string at levels positioned to seal with the surrounding well wall to isolate the several earth formations from each other, ports in the pipe string positioned to place the several isolated earth formations in separate fluid communication with the interior of the pipe strings, separate sleeve valve means mounted in the pipe string and selectively operable to open and close selected ones of said ports, each of said packers including a resilient seal element radially expandible by hydraulic pressure to seal with the well wall, conduit means for supplying said hydraulic pressure from the bore of said pipe string to actuate said seal elements, and release means on each of the packer bodies operable by limited rotation of the pipe string relative to the packer bodies to permit retraction of said seal elements from their sealing engagement with the well wall, each of said re lease means including a rotatable connection between the pipe string and the packer, said rotatable connection including stop means limiting the extent of relative rotation between the pipe string and each packer body whereby to successively transmit rotations of the pipe string to the several packer bodies.

References Cited in the file of this patent UNITED STATES PATENTS 2, 120,050 Ragan et al June 21, 1938 2,164,195 Waltermire June 27, 1939 2,177,601 Smith Oct. 24, 1939 2,537,066 Lewis Jan. 9, 1951 2,790,501 Garrett et al Apr. 30, 1957 2,804,830 Garrett et a1 Sept. 3, 1957 2,854,081 Kriegel Sept. 30, 1958 2,946,388 Evans July 26, 1960