US2998075A - Subsurface well apparatus - Google Patents

Description

Aug. 29, 1961 E. H. CLARK, JR

SUBSURFACE WELL APPARATUS 2 Sheets-Sheet 1 Filed July 29, 1957 INVENTOR.

BY MM WW/ ATTOAA/A'KS Aug. 29, 1961 E. H. CLARK, JR

SUBSURFACE WELL APPARATUS 2 sheets sheet 2 Filed July 29, 1957 I i rad liaA/fsr H 62 4e14, clz

INVENTOR.

ArroPn/EK? Unitc gillilools, Inc., Los Angeles, Calif., a corporation of orma Filed July 2-9, 1957, Ser. No. 674,965

16 Claims. (Cl. 166-194) The present invention relates to subsurface apparatus, particularly adapted for use within well bores. Various types of subsurface well bore apparatus are hydraulically or mechanically manipulated to produce relative movement between parts of the apparatus, for the purpose of accomplishing desired operations in the weIl bore. The required relative movement between the parts can sometimes be accomplished only with great difficulty, or cannot be achieved at all, since the parts bind upon one another. In many cases this binding can be attributed to the hydrostatic head of fluid in the well bore acting upon one or more parts of the apparatus and pressing or distorting such part against a companion member with tremendous force. If the parts include a hydraulic sealing ring, or the like, the ring might be subjected to a relatively high pressure differential resulting from a hydrostatic head of fluid acting on one side of the ring and the existence of air at substantially atmospheric pressure on its opposite side. deforms the ring and presses it with great force against a companion surface, which it grips tenaciously.

'In some apparatus, a part may bear against the wall of thewell bore, which precludes its movement when desired and appropriate operation of the apparatus. For example, well cementing apparatus to be incorporated in a string of well casing may include an exposed hydraulically shiftable outer sleeve valve, which could bear against the formation wall and thus be rendered immobile.

Accordingly, it is an object of the present invention to provide subsurface well bore apparatus having relatively movable parts, in which the hydrostatic head of fluid in the Well bore is incapable of causing such parts to bind upon one another, or of resisting their relative movement. Another object of the invention is to provide subsurface well bore apparatus incorporating a valve device movable between opened and closed positions, in which the hydrostatic head of fluid in the well bore cannot impose frictional restraint on the valve parts, which would tend to prevent movement between such positions.

A further object of the invention is to provide subsurface well bore apparatus incorporating a valve device movable between open and closed positions, leakage through the valve device being prevented by one or more sealrings, or the like, in which the hydrostatic head of fluid in the well bore cannot cause the seal ring or rings to seize or bind upon a companion sealing surface and thereby prevent appropriate operation of the valve device.

Yet another object of the invention is to provide subsurface well apparatus embodying an external sleeve valve for controlling passage of fluid through a side port in the apparatus, in which the sleeve valve is prevented from bearing against the wall of the well bore, so as to resist shifting of the sleeve valve relative to the port.

Still a further object of the invention is to provide subsurface side ported well apparatus for incorporation in a casing string, or similar conduit string, for use in cementing the casing string in a well bore, in which the ports are finally closed by an external sleeve valve which is fully protected against bearing upon the wall of the well bore, and in which the passage through the apparatus can be completely cleared of obstructions, resulting in an inner wall in the apparatus having substantially the sameinside diameter as the wall of an adjacent casing section.

invention possesses many other advantages, and

The pressure differential States Ptettt has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through the apparatus, with its side ports initially closed;

FIG. 2 is an enlarged fragmentary section similar to FIG. 1, with the side ports of the apparatus in an open condition;

FIG. 3 is a view similar to FIG. 2 illustrating the side ports of the apparatus reclosed;

FIG. 4 is an enlarged fragmentary section of a portion of the apparatus shown in FIG. 1;

FIG. 5 is a cross-section taken along the line 5-5 on FIG. 4.

The invention is illustrated in the drawings by way of example as being applied to a collar apparatus A which is to be connected to adjacent upper and lower casing sections B, C forming part of a casing string extending to the top of a well bore in which the casing string is disposed.

The apparatus will be described particularly with respect to the performance of a cementing operation, although itis tobe understood that in its broader aspects theinvention is not limited to casing cementing equipment.

The apparatus A includes a tubular member or body 10- having an upper threaded box 11 for threaded attachment to the lower pin end 12 of the adjacent upper casing section B, and a lower threaded pin 13 for threaded attacli-' ment to an adjacent coupling or box 14 of the lower casing section C. The diameter of the inner wall 15 of the tubu-- lar member is preferably equal to or greater than the inside diameter of the upper and lower casing section, so as to constitute an unobstructed continuation thereof The inner tubular member 10 has a plurality of circumferentially spaced side ports 16 extending completely through its wall, these ports being initially closed by a lower inner sleeve valve member 17 disposed across the port and slidable along the inner wall 15 of'the tubular member. The sleeve valve is initially held in closed position across the ports 16 by one or more shear screws 18 threaded into the tubular member and extending into a peripheral groove 19 in the inner sleeve member. Fluid: is prevented from leaking from the interior of the tubularmember 10 through the ports 16 and along the exterior of the lower sleeve valve member 17 by suitable seal rings 23, such as rubber or rubber-like upper and lower 0 rings, disposed in respective upper and lower peripheral grooves. 21 in the lower sleeve and bearing against the inner wall' of the tubular member on opposite sides of the ports (FIG. 1).

The ports 16 are opened upon the imposition'of a sufficient downward force on thelower inner sleeve member 17 to overcome the strength of the shear screws 18', the sleeve being shifted downwardly to a position deter-.- mined by its coming'to rest upon a plurality, such as, twofof cast iron keys or lugs 22 suitably secured to the: tubular member and projecting inwardly of its wall;

These keys or lugs will fit within companion longitudinal grooves 23 in the lower sleeve to with respect tothe tubular member.

The ports "16 in the tubular member can be closed by appropriate shifting of an external or shut-off sleeve 24 slidably mounted in an annular cylinder space 25 formed between the inner tubular member 10 andan' outer;

to the upper portion of the'tubular member '10' and the Patented Aug. 29, 19st prevent its rotation 3 lower end of which is constituted as a head 27 adapted to bear upon the lower tubular member. The inner wall 28 of the outer sleeve 26 is spaced radially from the outer suriace of tubular member lli, to define the annular cylinder space25 in -which the shut-oi? sleeve valve member is slidable. Initially, this shut-oft sleeve member 24 is disposed in an upper .position with respect to the -inner tubular member 10 and the outer sleeve or tubular member 26, being releasably held in such position by one or more shear screws 29 threaded in the lower portion of 'theshut-ofi sleeve and received within I a peripheral groove 30in the tubular member 10. When in such position, the shut-off sleeve has side ports '31 which have substantially the same diameter and are aligned with the ports 16 in the inner tubular member 10, and also with side ports 32 extending completely through the wall of the outer sleeve 26. Accordingly, when the lower inner sleeve member 17 has been shifted downwardly to a port opening position (FIG. 2), fluid can pass from the interior of the tubular member 10 through the ports 16, '31, '32 to the exterior of the apparatils. 7

When the shut-E sleeve'member 24 is disposed in its upper position between the inner tubular member and the outer-sleeve 26, its lower end is spaced a substantial distance 'aboye the lower head 27. The upper end 35 of the shut-off sleeve is then disposed adjacent a plurality of 'circurnferentially spaced side ports 36 extending through the upper portion of the inner tubular member or body 10, butnot extending into or through the outer sleeve 26. When fluid under pressure is allowed topass through the upper ports 36, they will act upon the upper end 35 of the shut-off sleeve member to overcome the shear strength of the screws 29holding the shut-0E sleeve to the body '10, shifting such sleeve downwardly to a position-in which its intermediate portion 37 ,is disposed across the body ,ports -16, closing the latter. Leakage of fluid through theports 16 is then prevented by suitable side seals 38, 39, such as upper and lower rubber or rubber-like '0 rings, disposed in respective upper and lower grooves 40 in the tubular'member on opposite sides of its .ports -16 and bearing against the inner wall or surface 41 of the shut-ofisleeve.

The lowermost position of the shut-off sleeve 24, when closing theports 16, is determined by engagement of its lower end with the lower head 27 of the outer sleeve. Return'movement of the shut-olf sleeve 24 toward a port opening position is prevented by a latch or lock element 42, in the form of asplit ring of triangular crosssection, contained within a groove 43 in the upper portidn'bf the sleeve 24 and having an upper inner corner 44 adapted to engage any one of a plurality of longitudinally arranged circumferential ratchet teeth 45 on the tubular memberiacin'g in a downward direction. The base '46 of the. groo e receiving the lock ring 42 is tapered in a downward and inward direction, so that any tendency of the shut-ofi sleeve 24 to shift upwardly from its port closing .position will cause the tapered base or surface 46 to cam the ring 42 inwardly and insure its engagement with a ratchettooth 45 on the tubular member 10. Actually, the lock or latch'ring 42 has an unrestrained internal diameter slightly less than the outside diameter of the portion of the tubular member along which it moves,so that it inherently-shifts inwardly into engagement with the ratchet teeth 45 when disposed 'therealong;

To insure against leakage of fluid along the exterior of the shut-off sleeve 24 and in through the upper port 36 when the shut-off sleeve is in its port closing position. a-s'ide seal 47 such as a rubber or rubber-like O tin-g. is disposed in an internal groove 48 in the outer sleeve memher 26 above the outer sleeve ports 32, which is adapted to sealingly engage the periphery of the shut-on sleeve portion37.

.-Fluid is initially .gprevented from passing through the 4 upper set of ports 36 into the cylinder space 25 for action upon the shut-off sleeve 24 by an upper inner sleeve valve member 49 which is disposed across these ports. Leakage of fluid between the upper sleeve valve member 49 and the inner wall of the tubular member 10 is prevented by upper and lower seal rings 50 such as rubber or rubber like Q rings, disposed in the respective upward "and lower peripheral grooves 51 in the upper sleeve valve members and sealingly engaging the inner tubular member 'or wall '15 on opposite sides of'the upper ports. The upper sleeve "valve member 49 is initially retained in closed position across these ports 36 by one or more shear screws 52 threaded in the tubular member 10 and disposed within a peripheral groove 53 in the upper sleeve valve member.

Fluid is prevented from passing through the upper ports 36 for action upon the valve sleeve 24 until a suflicient downward force has been imposed on the upper inner sleeve member 49 to overcome the shear strength of the screws 52 and shift the upper sleeve valve "member 49 to a downward position. Such shifting will occur after the lowerinner sleeve 17 has been shifted to its lower port opening position, whereupon the upper inner sleeve valve 49 can be shifted to its lowermost position, in which it comes to rest upon the lower sleeve 17, with its upper end disposed below the upper set of ports 36 and withits lower seal ring 50 preferably disposed above the main side ports 1-6 through the tubular member 14]. When the upper inner sleeve member 49 engages the lower inner sleeve member 17, a plurality of lugs or keys 55 extending upwardly from the lower member 17 are received within slots or recesses 56 in the lower end of the upper inner sleeve member 49, to prevent relative rotation between the parts for a'purpose that will be described hereinbelow.

-In the use of the apparatus so far described, the parts are initially disposed in the position illustrated in FIGS. 1 and 4, in which the shear screws 18, 52, 29ers all intact, the shut-01f sleeve 24 being disposed in its upper port opening position, the lower inner sleeve 17 closing the main ports 16 through the tubular member, and the upper inner sleeve 49 being disposed across the upper cylinder ports 36. It is to be noted that the lower inner sleeve member '17 has a generally cylindrical passage 57 therethrough which is smaller in diameter than the generally cylindrical passage 58 through the upper inner sleeve member 49. The upper inner end 17a of the lower inner sleeve 17 is beveled, which is also true of the upper inner end "49a of the upper inner sleeve member. Such beveled ends are vprovided primarily to function as guides for. plugs used in the cementing operation.

The apparatus A is secured to the adjacent casing sections B, C and the casing string is lowered in the well bore to the desired depth. Assuming that the apparatus is to be used in the performance of an upper stage of cementing the well casing in the well bore, the well bore is properly conditioned by pumping fluid through the casing string and upwardly through the annulus between the casing string and the wall of the well bore. A charge of cement slurry is then pumped into the casing string.

and will pass through the passages 53, 57 in the upper and lower inner sleeve members for continued downward movement through the casing string and for discharge therefrom at a lower point, such as from a casing shoe 61 provided with a lower downwardly tapering end 62 and a plurality of circurnterentially spaced longitudinally extending wings 63. This body portion is integral with,-

a valve head portion 64, wh-ich may have a downwardly tapering periphery, there being a side seal ring 65, made of rubber or rubber-like material mounted on the head. The maximum diameter of the head 64, and for that matter, of the entire trip plug, is less than the inside diameter of the upper inner sleeve valve member 49, so that the trip plug can pass therethrough. The body portion 61 of the trip plug 60 will extend into the lower inner sleeve member 17, the head seal 65 coming to rest upon the upper end 17a of the sleeve valve member 17 (FIG. 1). The seal ring 65 makes a positive seal with the lower inner sleeve member 17 preventing fluid from by-passing therearound. Accordingly, pressure can now be-built up in the liquid in the casing string above the trip plug 60 and when this pressure exceeds the shear strength of the shear screws 18 holding the lower inner sleeve member to the tubular body 10, the shear screws 18 are disrupted and the trip plug 60 and lower inner sleeve 17 are shifted downwardly to a position in which the lower inner sleeve comes to rest upon the stops or key members 22, which are in rotational locking engagement therewith. The upper end of the inner sleeve member 17 is then disposed immediately below the side ports 16, which are now in open condition (FIG. 2). Fluid can now be circulated down through the casing string and will pass outwardly through the open side ports 16, 31, 32 through the tubular member 10, shutoff sleeve 24 and outer sleeve 26, flushing any cement slurry above the ports upwardly out through the annulus to the top of the well bore. A suitable charge of cement slurry can now be pumped into the casing string with a shut-oil plug 68 mounted at its upper end. This charge of cement slurry and the shut-01f plug are pumped down the casing string through use of suitable displacement fluid. The shut-off plug 68 may be of any suitable type, including a lower head 69 having a downwardly tapering lower portion 70 and a side seal ring 71 mounted in a peripheral groove in the head. Above the seal 71 is a flange 72 having a lower shoulder 73 that tapers in a direction companion to the beveled or tapered upper end 49a of the upper inner sleeve member. A central stem or body 74 is attached to the head 69 and a rubber or rubber-like sealing member having the longitudinally spaced discs 75 is suitably secured around this stem. These discs or wipers 75 are adapted to sealingly slide along the wall of the well casing, to prevent contamination of the cement slurry by the following displacement The cement slurry will be pumped down through the casing, passing through the upper inner sleeve member 49 and through the ports 16, 31, 32 into the annulus around the casing string, continuing upwardly through the annulus toward the top of the well bore. The shut 01f plug 68 will engage the upper inner sleeve valve member 49, the tapered head 70 being appropriately guided into the passage 58 of the latter, with the flange 72 coming to rest upon the upper taper 49a of the inner sleeve member and with the rubber seal ring 71 engaging the inner cylindrical wall of the upper inner sleeve member 49. When this occurs, fluid cannot pass downwardly through the upper inner sleeve valve member 49. Increasing of the fluid pressure in the casing string above the shut-off plug 68 to an extent suflicient to overcome the shear strength of the screws 52 will disrupt the latter and enable the upper inner sleeve valve member 49 to be shifted downwardly to a position in which it comes into engagement with the upper end of the lower inner sleeve member 17. When in this position, the lower seal ring 50 of the upper member 49 is disposed above the main side ports 16, whereas the upper seal ring 50 on the upper sleeve member 49 will be disposed below the cylinder ports 36, which are now in an open condition.

The pressure of the fluid in the casing string above the upper inner sleeve member 49 and the shut-01f plug 68 can now be increased to a suflicient extent, such fluid pressure deflecting the wiper rings 75 downwardly and passing through the cylinder ports 36 into the cylinder space 25. The fluid acts over the upper area of the shut-01f sleeve 24, and when such pressure exceeds the shear strength of the screws 29, the shut-off sleeve is shifted downwardly to its fullest extent into engagement with the lower head 27, wherein the inner surface 41 of the shut-off sleeve is disposed across the tubular member ports 16 and in sealing engagement with the 0 rings 38, 39 and with its outer periphery in sealing engagement with the seal ring 47. The latch ring 42 can ratchet downwardly along the circular ratchet teeth 45 on the tubular member, but will engage one of the ratchet teeth to prevent return or upward movement in the shut-off sleeve 24 to a port opening position (FIG. 3.)

The ports 16 are now positively closed by the shut-0E sleeve 24, which will prevent cement slurry or any other fluids from passing in either direction through the ports 16 between the interior and exterior of the casing string. A suitable drill bit (not shown) may now be lowered on a drill string through the casing and such drill bit will disintegrate the upper and lower inner sleeves 49, 17 as well as the trip plug 60 and the shut-01f plug 68, such sleeves, plugs and the keys 22 preferably being made of readily drillable material, such as magnesium, cast-iron and rubber, so as to be disintegratable under the rotary action of the drill bit. The keys 22 secured to the tubular member 10 will prevent rotation of the lower inner sleeve 17 and the engagement of the lugs on the latter within the slots 56 in the upper sleeve member 49 will prevent rotation of the latter. Accordingly, the sleeves 49, 17 are preventedfrom rotating, so that the rotary action of the drill bit is eifective to accomplish their disintegration. When the interior of the tubular member 10 has been disintegrated under the action of the drill bit, all that remains is an uninterrupted inner wall of the tubular member which conforms to the inner walls of the upper; and lower casing section B, C secured to the apparatus A.

It is to be noted that the shut-off sleeve 24 is fully pro: tected by the outer sleeve 26 throughout its length. Ac-. cordingly, in the event the apparatus were to lean against the wall of the formation it will be the outer sleeve 26 that will bear upon the latter and not the shut-off sleeve. There is, therefore, no mechanical restriction to move ment of the shut-off sleeve 24 to a port closing position after its shear screws 29 have been disrupted.

The arrangement illustrated in the drawings also insuresthat the various parts are not subjected to distortion by the hydrostatic head of fluid in the well bore. In certain types of devices, 'certainof the parts would trap air sub st-antially at atmospheric pressure therein in confined spaces, as a result of assembly of the apparatus, these parts being subjected on one side to such air under atmospheric pressure only, while another-portion of the particular part'would be subjected to fluid pressure in the well bore, there being a pressure differential acting upon the parts that would tend to 'distort them and prevent proper operation of the apparatus.

As an example, if fluid were prevented from passing up: wardly along the shut-off sleeve 24, the inner and outer- 0 rings 38, 47 would seal thereagainst when the shut-off sleeve was in its upper position. In view of upper and lower 0 rings 50- on the upper inner sleeve valve member 49, air at atmospheric pressure would be trapped in any spaces above the inner and outer 0 rings 38, 47 and between the upper and lower seal rings 50. As the casing string is lowered through the drilling mud or other fluid in the well bore, the hydrostatic head of fluid would progressively increase, such hydrostatic head of fluid act ing upon'the lower end area of the shut-off sleeve 24 and tending to force it in an upward direction. This action would not only eventually disrupt the shear screws 29 holding the shut-off sleeve to the tubular member 10 when a suflicient depth in thewell bore was reached, but would also shift the shut-01f sleeve 24 upwardly and possibly:

7 .l its upper end against the tubular member or body 19.

Again, if the shut-off sleeve 24 were not protected by the outer sleeve 26, but was fully exposed to the external fluid pressure, air at atmospheric pressure might be trapped within the shut-off sleeve, the hydrostatic pres: sure then acting over the entire outer surface of the shutoff sleeve, tending to collapse and bind it inwardly upon the tubular member or body 10. Such inward collapsing could very well also bind or break the lock ring 42 on the body and prevent downward shifting of the shutoff sleeve 24. r

In addition, the trapping of air at atmospheric pressure around the upper inner sleeve valve member 49 and between its seal rings 50 would mean that each seal ring is subjected to a very high pressure differential as aresult of filling the casing string with fluid. There would be fluid under a'substantial pressure acting on the upper seal ring 50 tending to urge it downwardly and on the lower seal ring 50' tending to urge it upwardly. Such pressure differential is very often of such greatimagnitude that the seal rings 50' bind against the inner wall 15 of the tubular member 10, preventingthe upper inner sleeve valve -member from being released and shifted downwardly, despite the application of relatively high unit pressures to the liquid in the casing above the :apparatus A when the shut-E plug 68 seats within the upper inner sleeve 49. 1 i "By virtue of the present invention, theabilityof-the hydrostatic heads of fluid, whether internally or exterpally of the casing-string,-'to bind or lock the partsagainst movement is prevented. Instead, the parts are'freely movable when the restraining elements purposely incorporatedin the apparatus, such as the shear screws, are disrupted.

"It 'is to'be'noted that the seal rings "20' on the inner lower sleeve member 17 are not subjected to the pressure-dilferential oifered by hydrostatic'heads, since they are both simultaneously subject to the hydrostatic head of fluid externally of the casing string :and internally thereof, there being communication through the open 'ports 16 with the annulus around the casingfstring.

The space between the seal rings 50 of the upper inner sleevevalve member 49, and these seai rings themselves, are also made subject to the hydrostatic flow of fluid'in theannulus surrounding the casing string by permitting such fluid to pass through the ports 32 in the outer sleeve 26,upward ly' along the shut-elf sleeve'24, and through the cylinder ports 36 to the periphery of the upper inner sleeve 49 between the seal rings 50. For that matter, an extended peripheral groove 7 8 can be formed on the upper inner sleeve 49 adjacent the ports 36, insuring that thefluid can pass downwardly and upwardly along the sleeve 49 to its respective upper and lower seal rin'gsSll.

The fluid can passinthe manner just described'by providing elongateslots sl) through the shut-oil sleeve,

these slots preferably-extending from a region adjacent the lower external seal ring 39 on the tubular member 10, when the shear screws 29 are intact, to a'location above the inner and outer seal rings 38, 4 7 on the" body 10 and outer sleeve 26. Above these last -mentioned 0 rings, the tubular member 10 and outer sleeve 26 are both relieved, as by cutting an elongate circumferential groove" 82 in the exterior of the tubular member, these grooves being relatively shallow and terminating below the upper end of the shut-oifsleeve 24. In fact,-the distance be tween the upper end of the shut-oil sleeve 24 and the upper ends of the grooves 81, 82 is preferably greater: than the;d istance between the upper ends of the slots 80 and the inner and outer seal rings 38, 47, for a purpose that will bedescribed hereinbelow. The upper ends of the slots-80 extend above the lower ends of the internal and -external grooves V 81, :82 so that there is a'fluid' passage through the outer sleeve ports 32 and. along the slots'80, -the--fluid being capable of passing upwardly through the grooves 81, 82 to their upperends where the can pass through one or more radial holes 83 ex; tend-ing'through-the sleeve to its inner surface, the holes 83 extending into the lower end of the lock ring groove 43, continuing on through this groove and up through longitudinal slots 84 extending between the upper end 9f the groove 42 and the upper terminus of the sleeve 24. Such fluid can pass into the cylinder space 25 above shut-ofi sleeve 24, through the cylinder ports 36 into the space between the upper and lower seal rings 50 on the upper inner sleeve valve member 49.

The longitudinal slots 80, which are purposely made relatively narrow, might under some circumstances be come plugged with the drilling mud, thereby preventing the fluid under pressure from by passing around the shut-off sleeve 24 into the cylinder space 25 thereabove and the ports 36. Such plugging action is eliminated by cutting shallow helical grooves or threads 86 in the internal and external walls of the shut-off sleeve 24 in the region of its slotsSl) to the'upper ends of the latter and also from the upper holes 83 through the shut ofi sleege to its upper end. These grooves or threads 86 maybe -shaped with the outer ends 87 of the thread portions flattened so that they lie upon cylindrical surfaces, in order that the sleeve 24 can slide appropriately upon the companion surfaces of the tubular member 10 and the outer sleeve 26. To minimize frictional resistanceitp sleeve-262st its lower end-opening intothe annularspace 25a into which theshut-ofli sleeve 24 will move to port closing position.

The hydrostatic head. of fluid will now not only pass through therelatively narrow slots in the shu' qdfi sleeve 24, through the grooves 81, 82, the holes :83,- lock ring groove 43 and the narrow slots-84 in the uppermostportion of the shut-off sleevefbutit can also now pass in helical fashion through the thread er -helical grooves 86 formed in the inner and 'outer surfaces of the shut-ofi sleeve. Assurance is thus had that there is ample passage area for the drilling mud, or other fluid, to flow' upwardly along the internal and externalsurfaee of the shut-off sleeve 24 into the cylinder space 25 and the .ports 36 above its upper end, to insure equalizing of the fluid pressure attributed to the hydrostatic headof fluid externally of the casing string on the shut-,ofi sleeve 24, as wellas imposing such external hydrostatic head of fluid uponthe .sealrings 50 mounted in the upper inner sleeve member 49. Accordingly, when the casing string-is filled with fiuid, the pressure imposedonthe sleeve .49 by thehydrostatic head of fluid internally of the-casingstring and externally thereof is balanced acrosseach sealring 50. The upper seal .ring 50 is then only subject ot the pressure differential caused by subjecting the liquid thereabove to pressure, necessary to shear the screws'52. Suchpressure may be of the order of 500 to- 1,000 psi, which is insufficient to cause a binding action of .thegseal ring 50 against the inner wall of the tubular member 10. Accordingly, the upper inner sleeve 49 willbe released through disruption of its shear screws 52 at the predetermined pressure, and not at an inordinately high pressure.

After the upperinner sleeve valve member 49 has been shifteddownwardly to open the ports 36,-fiuid under pressure may' be pumped through the ports 36 at a suflicient rate tobujld up a back pressure acting on the upper end of-the -shut-off sleeve 24 to disrupt its shear screws 29 and move the sleeve downwardly to-a position closing the ports 16. Howeve n before thataction occurs, some of such fiuid will pass downwardly along the inner and outer surfaces ofthe shut-off sleeve '24 and may adversely affect the seal rings 358, 47. To preclude passing around the shut-off sleeve 24, while upward move. ment of fluid along both the inner and outer surfaces of the shut-off sleeve is permitted.

As illustrated in the drawings, a combination seal ring and check valve device 95 is mounted in the annular cylinder space 25 above the shut-off sleeve 24. This check valve element may be constituted as a rubber or rubber-like O ring adapted to seal against the adjacent periphery of the tubular member or body and also against the inner wall of the outer sleeve 26. It is adapted to occupy an uppermost position in engagement with the tubular member head 10a, in which position it is disposed at least partially above the lowermost ends of the cylinder ports 36, but only to a slight extent. In fact, it is preferred if pressure acting upwardly on the seal ring 95 be required to deform it slightly into the ports 36, in order that fluid may pass around this seal ring and into the ports 36 for action upon the seal rings 50 mounted on the upper inner sleeve valve member 49. However, when the fluid pressure is imposed in the opposite direction, as from the interior of the tubing string, after the upper inner sleeve 49 has been shifted downwardly to port opening position, the O ring seal 95 is shifted downwardly in the cylinder into engagement with the upper end of the shut-01f sleeve valve member 24. Not only does it engage the shut-ofi valve sleeve member, but it also sealingly engages the periphery of the tubular member 10 and the inner wall of the outer sleeve 26. Accordingly, pressure can now be imposed on the seal ring 95 and the upper end of the shut off sleeve 24 to shear the sleeve screws 29 and shift the shut-off sleeve 24 downwardly to its fullest extent onto a port closing position. In moving downwardly with the sleeve, the upper seal ring 95 will eventually reach the undercut or shallow groove portions 81, 82, wherein its sealing effectiveness will be lost. However, before this occurs, the inner and outer surfaces of the shut-off sleeve portion 37 above the slots 80, which do not have the grooves 86, willhave moved into sealing engagement with the inner and outer seal rings 38, 47, so that fluid is prevented from by-passing down around the shut-off sleeve 24.

With the check valve arrangement 95, fluid is still permitted to, pass through the outer sleeve ports 32 and upwardly along the interiors and exteriors of the shut-off sleeve 24, this fluid passing into the cylinder space 25 above the upper sleeve and shifting the check valve ring 95 upwardly against the head 10a, whereupon the pressure will distort it sufliciently to pass around it and into the ports 36, the fluid then being capable of movement into the peripheral groove 78 in the inner upper sleeve valve member 49, and of acting upon the upper and lower seal rings 50. However, when the shut-off sleeve 24 is to be shifted downwardly, following opening of the circulation ports 36, the fluid pressure shifts the ring 95 downwardly upon the upper end of the shut-off sleeve 24 into sealing engagement with the periphery of the tubular member 10 and the inner wall of the outer sleeve 26, so that the full fluid pressure is imposed on the sleeve 24 to disrupt the screws 29 and shift it to its port closing position (FIG. 3).

It is, accordingly, apparent that an apparatus has been provided in which the shut-off sleeve 24 is fully protected from engagement with the wall of the formation. It cannot, therefore, be distorted by such formation wall. Any bearing force against the formation is taken by the outer sleeve 26, which can be made of an ample wall thickness to resist deformation. In addition, by-pass passages are provided to equalize the hydrostatic pressures externally of the casing string and acting upon the shutoff sleeve, and also upon all of the seal rings in the device that would otherwise be subjected to hydrostatic pressure difierentials resulting from the entrapping of air at substantially atmospheric pressures on one side of particular seal rings. Not only would the seal rings be deformed by the pressure differential to such an extent as to resist movement of the parts, but the parts themselves "might be subjected to collapsing forces that would bind them, metal-to-metal, upon one another, causing great difliculty in shifting the parts, and at times freezing them to the point of immobility under any pressures or forces that might be safely imposed upon the equipment.

The inventor claims:

1. In apparatus of the character described: a tubular member having a first side port and adapted to form part of a conduit string positionable in a well bore; an outer sleeve secured to said member and spaced laterally outwardly thereof to define an annular cylinder space therewith; a shut-off sleeve valve member in said cylinder space disposed initially in an upper position to allow fluid passage through said side port; means providing a slid able seal between said sleeve valve member and tubular member; means providing a slidable seal between said sleevevalve member and the outer sleeve; said tubular member having a second side port opening into the interior of said member and said cylinder space; a-lower sleeve valve member slidable in said tubular member and disposed initially across said first port to close the same; an upper sleeve valve member above said lower sleeve valve member slidable in said tubular member and disposed initially across said second port to close the same; said lower member being shiftable downwardly in said tubular member to open said first port; said upper member being shiftable downwardly in said tubular member to open said second port to enable fluid under pressure to pass from the interior of the tubular member into said cylinder space to shift said shut-off sleeve valve member downwardly of said tubular member to a position closing. said first port.

2. In apparatus of the character described: a tubular member having a first side port and adapted to form part of a conduit string positionable in a well bore; an outer sleeve secured to said member and spaced laterally out-- ward thereof to define an annular cylinder space therewith; said sleeve having a side port; a shut-off sleeve. valve member in said cylinder space having a side port and disposed initially in an upper position with its sideport in substantial alignment with said tubular memberand sleeve ports; means providing a slidable seal between said sleeve valve member and tubular member;

means providing a slidable seal between said sleeve valve.

member and the outer sleeve; said tubular member having a second side port opening into its interior and said cyl-, inder space above said shut-01f sleeve valve member; a lower sleeve valve member slidable in said tubular mem-.

ber and disposed initially across said first port to close the same; an upper sleeve valve member above said.-

lower. sleeve valve member slidable in said tubular member and disposed initially across said second port to closev the same; said lower member being shiftable downwardly in said tubular member to open said first port; said upper member being shiftable downwardly in said tubular mem-- ber to open said second port and enable fluid under pres sure to pass from the interior of said tubular member into said cylinder spaceto shift said shut-off sleeve valve mem ber downwardly of said tubular member to a position closing said first port.

3. In apparatus of the character described: a tubular. member having a side port and adapted to form part of a conduit string positionable in a well bore; a shiftable sleeve valve member on the exterior of said tubular valve member along said tubular member to port closing position; and fluid conducting means providing an equalizing passage for fluid from the exterior ofsaid sleeve valve member to its interior, whereby fluidv pressure externally of said sleeve valve member acts simultaneously on its inner and outer surfaces, along their entire areas.

allow fluid passage through said first port; said tubular member having a second side port opening into the interior of said member and said cylinder space; an inner sleeve valve member slidable in said tubular member and disposed initially across said second port to close the same; said inner member being shiftable downwardly in said tubular member to open said second port to enable fluid under pressure to pass from the interior of said tubular member into said cylinder space to shift said shut-ofl sleeve valve member downwardly of said tubular member to a position closing said port; means providing an equalizing passage for fluid from the exterior of said outer sleeve along the entire inner and outer surfaces of said shut-oft sleeve valve member to said second port, whereby fluid pressure externally of said shut-off sleeve valve member acts simultaneously on said surfaces and also on the exterior of said inner valve member; and seal means engageable with said shut-ofi sleeve valve member to close said equalizing passage in response to fluid pressure within said tubular member and second port.

11. In apparatus of the character described: a tubular member having a first side port and adapted to form part of a conduit string positionable in a well bore; an outer sleeve secured to said member and spaced laterally outwardly thereof to define an annular cylinder space therewith; said tubular member having a second side port opening into the interior of said member and said cylinder space; a shut-off sleeve valve member in said cylinder space disposed initially in an upper position to allow fluid passage through said first port; an inner sleeve valve member slidable in said tubular member and initially disposed across its second port to close the same; seal means above and below said second port for effecting a slidable seal between said inner valve member and tubular member; said inner member being shiftable downwardly in said tubular member to open said second port to enable fluid under pressure to pass from the interior of said tubular member and into said cylinder space to shift said shut-ofl sleeve valve member downwardly of said tubular member to a position closing said first port; and means providing an equalizing passage for fluid from the exterior of said outer sleeve along the entire inner and outer surfaces of said shut-oif sleeve valve member to said second port, whereby fluid pressure externally of said shut-off sleeve valve member acts simultaneously on said surfaces and also on the exterior of said inner valve member and on said seal means; and seal means en-gageable with said shut-ofi sleeve valve member to close said equalizing passage in response to fluid pressure within said tubular member and second port.

12. In apparatus of the character described: a tubular member having an inner passage and adapted to be disposed in a well bore; means slidable on said member; said member having an opening establishing fluid communication between said passage and said means to hydraulically operate said means; and fluid conducting means providing an equalizing passage for fluid from the exterior of said slidable means to its interior, whereby fluid pressure externally of said slidable means acts simultaneously on its inner and outer surfaces along their entire areas to equalize the pressure thereon.

13. In apparatus of the character described: a tubular member having an inner passage and adapted to be disposed in a well bore; means slidable on said member; said member having an opening establishing fluid communication between said passage and said means to hydraulically operate said means; fluid conducting means providing an equalizing passage for fluid from the exterior of said slidable means to its interior, whereby fluid pressure externally of said slidable means acts simultaneously on its inner and outer surfaces along their entire areas to equalize the pressure thereon; and means closing said equalizing passage in response to fluid pressure within said member passage and opening.

14. In apparatus of the character described: a first member adapted to be disposed in a well bore; an annular member mounted for relative sliding along said first memher and subject to the pressure of fluid in the well bore externally of said apparatus; said annular member having a close working fit with said first member; one of said members having a groove confronting said other member which establishes fluid communication between the interior and exterior of said annular member, whereby the pressure externally of said apparatus acts simultaneously on the interior and exterior of said annular member to equalize the pressure thereon.

15. In apparatus of the character described: a first member adapted to be disposed in a well bore; an annular member mounted for relative sliding along said first member and subject to the pressure of fluid in the Well bore externally of said apparatus; said annular member having a close working fit with said first member; said annular member having a helical groove confronting said first member which establishes fluid communication between the interior and exterior of said annular member, whereby the pressure externally of said apparatus acts simultaneously on the interior and exterior of said annular member to equalize the pressure thereon.

16. In apparatus of the character described: a first member adapted to be disposed in a well bore; an annular member slidably mounted along the exterior of said first member and subject to the pressure of fluid in the well bore externally of said annular member; said annular member having a close working fit with said first member; said annular member having a helical groove on its inner surface confronting said first member, which groove establishes fluid communication between the interior and exterior of said annular member, whereby the pressure externally thereof acts simultaneously on the interior and exterior of said annular member to equalize the pressure thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,429,912 Baker Oct. 28, 1947 2,502,886 Ragan Apr. 4, 1950 2,630,999 Lee Mar. 10, 1953 2,633,916 Baker Apr. 7, 1953

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