Washpipeless isolation strings and methods for isolation with object holding service tool

An isolation string having an upper packer and an isolation pipe in mechanical communication with the upper packer, the isolation pipe comprises an operable valve and an object activated valve. An object holding service tool is adapted to release an object to activate the object activated valve. A method of running-in an isolation string, comprising an operable valve and an object activated valve, with an object holding service tool having an object held therewith; setting the isolation string in the casing adjacent perforations; pressurizing the object to cause a release from the object holding service tool, whereby the object travels to the object activated valve; closing the object activated valve with the released object; and withdrawing the object holding service tool from the well.

FIELD OF THE INVENTION

The present invention relates to the field of well completion assemblies for use in a well. More particularly, the invention relates to valves used for production zone isolation.

BACKGROUND OF THE INVENTION

Early prior art isolation systems involved intricate positioning of tools which were installed down-hole after the gravel pack. These systems are exemplified by a commercial system which at one time was available from Baker. This system utilized an anchor assembly which was run into the wellbore after the gravel pack. The anchor assembly was released by a shearing action, and subsequently latched into position.

Certain disadvantages have been identified with the systems of the prior art. For example, prior conventional isolation systems have had to be installed after the gravel pack, thus requiring greater time and extra trips to install the isolation assemblies. Also, prior systems have involved the use of fluid loss control pills after gravel pack installation, and have required the use of thru-tubing perforation or mechanical opening of a wireline sliding sleeve to access alternate or primary producing zones. In addition, the installation of prior systems within the wellbore require more time consuming methods with less flexibility and reliability than a system which is installed at the surface.

Later prior art isolation systems provided an isolation sleeve which was installed inside the production screen at the surface and thereafter controlled in the wellbore by means of an inner service string. For example, as shown in U.S. Pat. No. 5,865,251, incorporated herein by reference, illustrates an isolation assembly which comprises a production screen, an isolation pipe mounted to the interior of the production screen, the isolation pipe being sealed with the production screen at proximal and distal ends, and a sleeve movably coupled with the isolation pipe. The isolation pipe defines at least one port and the sleeve defines at least one aperture, so that the sleeve has an open position with the aperture of the sleeve in fluid communication with the port in the isolation pipe. When the sleeve is in the open position, it permits fluid passage between the exterior of the screen and the interior of the isolation pipe. The sleeve also has a closed position with the aperture of the sleeve not in fluid communication with the port of the isolation pipe. When the sleeve is in the closed position, it prevents fluid passage between the exterior of the screen and the interior of the isolation pipe. The isolation system also has a complementary service string and shifting tool useful in combination with the isolation string. The service string has a washpipe that extends from the string to a position below the sleeve of the isolation string, wherein the washpipe has a shifting tool at the end. When the completion operations are finalized, the washpipe is pulled up through the sleeve. As the service string is removed from the wellbore, the shifting tool at the end of the washpipe automatically moves the sleeve to the closed position. This isolates the production zone during the time that the service string is tripped out of the well and the production seal assembly is run into the well.

Prior art systems that do not isolate the formation between tool trips suffer significant fluid losses Those prior art systems that close an isolation valve with a mechanical shifting tool at the end of a washpipe prevent fluid loss. However, the extension of the washpipe through the isolation valve presents a potential failure point. For example, the washpipe may become lodged in the isolation string below the isolation valve due to debris or settled sand particles. Also, the shifting tool may improperly mate with the isolation valve and become lodged therein.

Therefore, a need remains for an isolation system for well control purposes and for wellbore fluid loss control which combines simplicity, reliability, safety and economy, while also affording flexibility in use. A need remains for an isolation system which does not require a washpipe with a shifting tool for isolation valve closure.

BRIEF SUMMARY OF THE INVENTION

The invention includes in one embodiment an isolation string having an upper packer and an isolation pipe in mechanical communication with the upper packer, the isolation pipe comprising an operable valve and an object activated valve, and the isolation string coupled to an object holding service tool adapted to release an object to engage the object activated valve. The present invention also includes in one embodiment a method of running-in an isolation string with an object holding service tool having an object held therewith into the well, the isolation string comprising an operable valve and an object activated valve; setting the isolation string in the casing adjacent perforations; pressurizing the object to cause a release from the object holding service tool, whereby the object travels to the object activated valve; closing the object activated valve with the released object; and withdrawing the object holding service tool from the well.

One aspect includes four separate valves in combination: a Radial Flow Valve (RFV), an Annular Flow Valve (AFV), a Pressure Activated Control Valve (PACV), and an Interventionless Flow Valve (IFV). Generally, the RFV is an annulus to inside diameter pressure actuated valve with a double-pin connection at the bottom, the AFV is an annulus to annulus pressure actuated valve with a double-pin connection at the bottom, the PACV is an outside diameter to inside diameter pressure actuated valve, and the IFV is an outside diameter to inside diameter object actuated valve. A double-pin or double-sub connection is one having concentric inner and outer subs.

The present invention provides a valve system for a well, comprising: an isolation string, comprising an upper packer and an isolation pipe in mechanical communication with the upper packer, wherein the isolation pipe comprises a pressure activated valve, an object activated valve; and an object holding service tool coupled to the object activated valve and adapted to release an object to engage the object activated valve.

The present invention provides a method for isolating a production zone of a well, comprising: running-in an isolation string with an object holding service tool having an object held therewith into the well, the isolation string comprising a pressure activated valve, and an object activated valve; setting the isolation string in the casing adjacent perforations in the casing; pressurizing an area of the object to cause the object to be released from the object holding service tool, whereby the object travels to the object activated valve; at least partially closing the object activated valve with the released object; and withdrawing the object holding service tool from the well.

The present invention provides a valve system for a well, comprising: an isolation string, comprising an upper packer; a pressure activated, double-sub valve comprising first and second concentric subs, wherein the double-sub valve is in mechanical communication with the upper packer; an isolation pipe in mechanical communication with the first sub of the double-sub valve, wherein the isolation pipe comprises an object activated valve; and a production pipe in mechanical communication with the second sub of the double-sub valve; and further comprising an object holding service tool coupled to the object activated valve and comprising a holding barrel having a bore in which an object is slidably and sealingly engaged, the object holding service tool being adapted to slidably release the object with sufficient pressure applied to the object to cause a restraining device holding the object to release the object.

The present invention further provides a method for isolating a production zone of a well, comprising: running-in an isolation string with an object holding service tool having an object held therewith into the well, wherein the isolation string comprises a double-sub valve, and an object activated valve; setting the isolation string in the casing adjacent perforations in the casing; pressurizing an area on the object to cause the object to be released from the object holding service tool, whereby the object travels to the object activated valve; at least partially closing the object activated valve with the released object; and withdrawing the object holding service tool from the isolation string.

The present invention also provides a valve system for a wellbore, comprising: an object; an object holding service tool comprising a holding barrel having a bore in which the object is slidably and sealingly engaged, the object holding service tool being adapted to slidably release the object with sufficient pressure applied to the object to cause a restraining device holding the object to release the object, and an object activated valve, comprising a tube having at least one opening, a sleeve being movably connected to the tube, wherein the sleeve covers the at least one opening in a closed configuration and the sleeve does not cover the at least one opening in an open configuration, and an object seat in mechanical communication with the sleeve, wherein the seat receives an object for manipulating the valve from the open configuration to the closed configuration.

Further, the present invention provides an object holding service tool to actuate a downhole valve in a well, comprising a holding barrel having a bore adapted to slidably and sealingly engage an object held therewith, the object holding service tool being adapted to slidably release the object with sufficient pressure applied to the object to cause a restraining device holding the object to release the object.

The present invention also provides a valve system for a well having multiple zones for isolation, comprising: an isolation string, comprising a lower isolation section having a lower section upper packer and a lower section isolation pipe in mechanical communication with the lower section upper packer, wherein the lower section isolation pipe comprises a pressure activated valve and a lower section object activated valve; the isolation string also having an upper isolation section, comprising an upper section upper packer, a double-sub valve comprising first and second concentric subs, wherein the double-sub valve is in mechanical communication with the upper section upper packer; an upper section isolation pipe in mechanical communication with the first sub of the double-sub valve, wherein the isolation pipe comprises an upper section object activated valve; and a production pipe in mechanical communication with the second sub of the double-sub valve; wherein the upper section isolation pipe and the production pipe sting into the lower section upper packer; and further comprising an object holding service tool, comprising a holding barrel having a bore in which an object is slidably and sealingly engaged, the object holding service tool being adapted to slidably release the object with sufficient pressure applied to the object to cause a restraining device holding the object to release the object, the object holding service tool being coupled to at least one of the isolation sections.

The invention also provides a downhole assembly, comprising an object; an object holding service tool adapted to selectively hold the object; and a means for releasing the object from the object holding service tool.

In yet another embodiment, the invention provides a valve system for a well, comprising an isolation string having an upper packer and an isolation pipe in mechanical communication with the upper packer, wherein the isolation pipe comprises an operable valve and an object activated valve; and further comprising an object holding service tool coupled to the object activated valve and adapted to release an object to engage the object activated valve.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention are illustrated in the Figures, like numeral being used to refer to like and corresponding parts of the various drawings.

The present invention includes various valves, herein “operable valves”, as part of the system or method, which can be themselves embodiments of the present invention. A Radial Flow Valve (RFV) is an annulus to inside diameter pressure actuated valve with a double pin connection at the bottom. An Annular Flow Valve (AFV) is an annulus to annulus pressure actuated valve with a double pin connection at the bottom. A Pressure Activated Control Valve (PACV) is an outside diameter to inside diameter pressure actuated valve. An Interventionless Flow Valve (IFV) is an outside diameter to inside diameter object actuated valve. Other valves such as mechanically operated valves, including those valves with sliding sleeves, can be used with the present invention.

Referring toFIGS. 1A–1Cand2A–2C, detailed drawings of an AFV are shown. InFIGS. 1A–1C, the valve is shown in an open position and inFIGS. 2A–2C, the valve is shown in a closed position. The terms “open” and “uncovered” and “closed” and “cover” and variations thereof are used broadly herein. For example, the terms “open” or “uncovered” position can include at least partially open such as elements are disengaged so that fluid can flow through the valve. Similarly, “closed” or “covered” can include at least partially closed such that elements are engaged so that fluid is restricted or stopped from flowing through the valve.

In the open position, the valve enables fluid communication through the annulus between the interior and exterior tubes of the isolation string. Essentially, these interior and exterior tubes are sections of the base pipe16and the isolation pipe17, wherein a lower annulus65is defined between. The AFV comprises a shoulder52that juts into the annulus between a small diameter sealing land58and a relatively large diameter sealing land59. A moveable joint54is internally concentric to the shoulder52and the sealing lands58and59. Seals56are positioned between the moveable joint54and the sealing lands58and59. The movable joint54has a spanning section62and a closure section64, wherein the outside diameter of the spanning section62is less than the outside diameter of the closure section64.

The AFV is in a closed position, as shown inFIGS. 2A–2C, when the valve is inserted in the well. In the closed position, the closure section64of the movable joint54covers lower ports67. The AFV is held in the closed position by a shear pin55. The shear pin55holds a lock ring53in a fixed position relative to the isolation pipe17. A certain change in fluid pressure differential between an upper annulus66of the AFV and the tubing, usually a pressure increase in the tubing, causes the moveable joint54to shift. In particular, excess tubing pressure is communicated through ports51to operate against annular wall57. Because the small diameter sealing land58is relatively smaller than the large diameter sealing land59, the relatively higher tubing pressure drives the movable joint54in the direction of the lock ring.53. The movable joint54continues to drive against the lock ring53until the force is sufficient to shear the shear pin55. Upon shear, both the lock ring53and the movable joint54move in the direction of the isolation pipe17until the movable joint54is in an open configuration, as shown inFIGS. 1A–1C. When the movable joint54is in the open configuration, the spanning section62of the movable joint54spans the lower ports67. This allows fluid to pass freely through the AFV between the lower annulus65, through lower ports67, through upper ports68, and through the upper annulus66.

The other double-pin valve is the RFV, as shown inFIGS. 3A–5C. Similar to the AFV shown inFIGS. 1A–1Cand2A–2C, the RFV has inner and outer concentric subs. Also, the RFV is pressure activated. InFIGS. 3A–3C, the RFV is shown in an open configuration. InFIGS. 4A–4C, the RFV is shown in a closed, unlocked (sheared) configuration. InFIGS. 5A–5C, the RFV is shown in a closed, locked configuration.

Referring toFIGS. 3A–5C, the a cross-sectional side view of the RFV300is shown. The RFV300comprises a double-wall construction made up of an inner tube301and an outer tube302. At the bottom of the valve there are inner and outer subs303and304, respectively. A fluid flow path is defined by the inner and outer subs303and304to communicated fluid between the subs up to ports305. The RFV300also has a sleeve306which is slidable within the inner tube301of the valve. The lower portion of the sleeve306is formed to slide over the ports305to completely restrict the flow of fluid through the ports305. A pressure chamber307is defined by a portion of the sleeve305and a portion of a mounting ring308. The inner and outer tubes301and302are mounted to the top of the mounting ring308and the inner and outer subs303and304are mounted to the bottom of the mounting ring308. The ports305extend through the mounting ring308. The valve also has a spring-biased lock ring309which engages teeth on the sleeve306.

Typically, the RFV300is run in the well in a closed-locked configuration, as shown inFIGS. 5A–5C. In the closed-locked configuration, the sleeve306covers the ports305. The RFV300is held in the closed-locked configuration by lock ring313. The lock ring313has inner and outer rings which telescope into each other. The lock ring313is secured in an extended position by shear screws314. In the extended position, the shear screws are screwed through both inner and outer rings of the lock ring313. Because the lock ring313is fixed in an extended position, the lock ring313and sleeve306are unable to slide in the direction of the inner sub303. The sleeve306is also secured to the mounting ring308to prevent it from sliding in the opposite direction of the inner sub303. The sleeve306is secured to the mounting ring308by a snap ring318, which is spring biased to expand itself radially outward. However, in the closed-locked configuration, the snap ring318is held in a groove in the outside, lower end of the sleeve306by the lowermost portion of the mounting ring308. At the lowermost portion of the mounting ring308, there is a shoulder319which prevents the snap ring318, and hence the sleeve306, from sliding in a direction away from the inner sub303.

The RFV300may be reconfigured to a closed-unlocked (sheared) configuration, as shown inFIGS. 4A–4C. The RFV300is unlocked by creating a pressure differential between the inner diameter of the sleeve306and the pressure chamber307. Fluid from the inner diameter bleeds through ports315in the sleeve306to work against annular wall316. The sleeve306has a greater outside diameter above the pressure chamber307than it has below the pressure chamber307. Thus, a relatively higher fluid pressure in the inner diameter of the sleeve306compared to the pressure chamber307, drives the sleeve306toward the inner sub303. As the sleeve306slides toward the inner sub303, it bears on the lock ring313. When the downward force becomes great enough, the lock ring313shears the shear screws314to release the inner and outer rings of the lock ring313so they are able to collapse into each other. Upon release, the lock ring313collapses and the sleeve306continues to move downwardly until they come to rest in the closed-unlocked (sheared) configuration shown inFIGS. 4A–4C. As the sleeve306moves downward, the snap ring318is pushed into a larger bore and expands out of the groove in the sleeve306to release the sleeve306from the mounting ring308. In this position, the snap ring318holds the lock ring313in its sheared position. This RFV configuration is closed because the sleeve306is over the ports305to completely restrict the flow of fluid through the ports305. Seals317are positioned above and below the ports305to ensure the integrity of the valve.

The RFV300also has a spring320which works between the lock ring309and a seal sleeve321to bias the sleeve306in the direction away from the inner sub303. As noted above, the lock ring309is secured to the sleeve306by teeth311on the mating surfaces. In the closed-unlocked configuration of the RFV300, the spring320is fully compressed, as shown inFIG. 4A.

FIGS. 3A–3Cillustrate the RFV300in an open configuration. The valve is opened by reducing the pressure differential between the inner diameter of the sleeve306and the pressure chamber307. When this pressure differential is reduced, the spring320pushes the sleeve306away from the ports305in a direction opposite from the inner sub303until the ports305are uncovered and until the lock ring309engages a shoulder312. The valve also has a ratchet lock ring322between the seal sleeve321and the sleeve306. As the sleeve306is pushed by the spring320, the ratchet lock ring322jumps over the teeth on the sleeve306as it moves into the open position. Because of the configuration of the threads on the ratchet lock ring322and sleeve306, the sleeve306is held in the open position by the ratchet lock ring322regardless of subsequent changes in the pressure differential.

Alternately, the RFV300may be opened by engaging the inner diameter profile323in the sleeve306with any one of several commonly available wireline or coiled tubing tools (not shown). Applying a downward force to the sleeve306shears the shear screws314and releases the snap ring318. The spring320then pushes the sleeve306away from the ports305into the open position as described above. The wireline or coiled tubing tool is then released from the inner diameter profile323and removed from the well.

Two additional valves are utilized in different embodiments of the isolation strings of the present invention. The valves are placed in an isolation tube, which may be wire wrapped or placed adjacent a production screen as discussed below. One of the valves is pressure activated while the other is object activated.

Referring toFIGS. 6A–6D, there is shown a Pressure Activated Control Valve (PACV) in a production tubing assembly110. The production tubing assembly110is mated in a conventional manner and will only be briefly described herein. Assembly110includes isolation pipe140that extends above the assembly and a production screen assembly112with the PACV assembly108controlling fluid flow through the screen assembly. In this illustration, the production screen assembly112is mounted on the exterior of PACV assembly108. PACV assembly108is interconnected with isolation pipe140at the uphole end by threaded connection138and seal136. Similarly on the downhole end169, PACV assembly108is interconnected with isolation tubing extension113by threaded connection122and seal124. In the views shown, the production tubing assembly110is disposed in well casing111and has inner tubing114, with an internal bore115, extending through the inner bore146of the assembly.

Referring now more particularly to PACV assembly108, there is shown outer sleeve upper portion118joined with an outer sleeve lower portion116by threaded connection128. Outer sleeve upper portion118includes a plurality of production openings160for the flow of fluid from the formation when the valve is in an open configuration. For the purpose of clarity in the drawings, these openings have been shown at a 45° inclination. Outer sleeve upper portion118also includes through bores148and150. Disposed within bore150is shear pin151, described further below. The outer sleeve assembly has an outer surface and an internal surface. On the internal surface, the outer sleeve upper portion118defines a shoulder188(seeFIG. 6C) and an area of reduced wall thickness extending to threaded connection128resulting in an increased internal diameter between shoulder188and connection128. Outer sleeve lower portion116further defines internal shoulder189and an area of reduced internal wall thickness extending between shoulder189and threaded connection122. Adjacent threaded connection138, outer sleeve portion118defines an annular groove176adapted to receive a locking ring168.

Referring now more particularly to PACV assembly108, there is shown outer sleeve upper portion118joined with an outer sleeve lower portion116by threaded connection128. For the purpose of clarity in the drawings, these openings have been shown at a 45° inclination. Outer sleeve upper portion118includes a plurality of production openings160for the flow of fluid from the formation when the valve is in an open configuration. Outer sleeve upper portion118also includes through bores148and150. Disposed within bore150is shear pin151, described further below. The outer sleeve assembly has an outer surface and an internal surface. On the internal surface, the outer sleeve upper portion118defines a shoulder188(seeFIG. 6C) and an area of reduced wall thickness extending to threaded connection128resulting in an increased internal diameter between shoulder188and connection128. Outer sleeve lower portion116further defines internal shoulder189and an area of reduced internal wall thickness extending between shoulder189and threaded connection122. Adjacent threaded connection138, outer sleeve portion118defines an annular groove176adapted to receive a locking ring168.

Disposed within the outer sleeves is inner sleeve120. Inner sleeve120includes production openings156which are sized and spaced to correspond to production openings160, respectively, in the outer sleeve when the valve is in an open configuration. Inner sleeve120further includes relief bores154and142. On the outer surface of inner sleeve there is defined a projection defining shoulder186and a further projection152. Further inner sleeve120includes a portion121having a reduced external wall thickness. Portion121extends down hole and slidably engages production pipe extension113. Adjacent uphole end167, inner sleeve120includes an area of reduced external diameter174defining a shoulder172.

In the assembled condition shown inFIGS. 6A–6D, inner sleeve120is disposed within outer sleeves116and118, and sealed thereto at various locations. Specifically, on either side of production openings160, seals132and134seal the inner and outer sleeves. Similarly, on either side of shear pin151, seals126and130seal the inner sleeve and outer sleeve. The outer sleeves and inner sleeve combine to form a first chamber155defined by shoulder188of outer sleeve118and by shoulder186of the inner sleeve. A second chamber143is defined by outer sleeve116and inner sleeve120. A spring member180is disposed within second chamber143and engages production tubing113at end182and inner sleeve120at end184. A lock ring168is disposed within recess176in outer sleeve118and retained in the recess by engagement with the exterior of inner sleeve120. Lock ring168includes a shoulder170that extends into the interior of the assembly and engages a corresponding external shoulder172on inner sleeve120to prevent inner sleeve120from being advanced in the direction of arrow164beyond lock ring168while it is retained in groove176.

The PACV assembly has three configurations as shown inFIGS. 6A–8E. In a first configuration shown inFIGS. 6A–6D, the production openings156, in inner sleeve120are axially spaced from production openings160along longitudinal axis190. Thus, PACV assembly108is closed and restricts flow through screen112into the interior of the production tubing. The inner sleeve is locked in the closed configuration by a combination of lock ring168which prevents movement of inner sleeve120up hole in the direction of arrow164to the open configuration. Movement down hole is prevented by shear pin151extending through bore150in the outer sleeve and engaging an annular recess in the inner sleeve. Therefore, in this position the inner sleeve is in a locked closed configuration.

In a second configuration shown inFIGS. 7A–7D, shear pin151has been severed and inner sleeve120has been axially displaced down hole in relation to the outer sleeve in the direction of arrow166until external shoulder152on the inner sleeve engages end153of outer sleeve116. The production openings of the inner and outer sleeves continue to be axial displaced to prevent fluid flow therethrough. With the inner sleeve axial displaced down hole, lock ring168is disposed adjacent reduced outer diameter portion174of inner sleeve120such that the lock ring may contract to a reduced diameter configuration. In the reduced diameter configuration shown inFIG. 7, lock ring168may pass over recess176in the outer sleeve without engagement therewith. Therefore, in this configuration, inner sleeve is in an unlocked position.

In a third configuration shown inFIGS. 8A–8E, inner sleeve120is axially displaced along longitudinal axis190in the direction of arrow164until production openings156of the inner sleeve are in substantial alignment with production openings160of the outer sleeve. Axial displacement is stopped by the engagement of external shoulder186with internal shoulder188. In this configuration, PACV assembly108is in an open position.

In the operation of a preferred embodiment, at least one PACV is mated with production screen112and, production tubing113and140, to form production assembly110. The production assembly according toFIG. 4with the PACV in the locked-closed configuration, is then inserted into casing111until it is positioned adjacent a production zone (not shown). When access to the production zone is desired, a predetermined pressure differential between the casing annulus144and internal annulus146is established to shift inner sleeve120to the unlocked-closed configuration shown inFIG. 7. It will be understood that the amount of pressure differential required to shift inner sleeve120is a function of the force of spring180, the resistance to movement between the inner and outer sleeves, and the shear point of shear pin151. Thus, once the spring force and resistance to movement have been overcome, the shear pin determines when the valve will shift. Therefore, the shifting pressure of the valve may be set at the surface by inserting shear pins having different strengths.

A pressure differential between the inside and outside of the valve results in a greater amount of pressure being applied on external shoulder186of the inner sleeve than is applied on projection152by the pressure on the outside of the valve. Thus, the internal pressure acts against shoulder186to urge inner sleeve120in the direction of arrow166to sever shear pin151and move projection152into contact with end153of outer sleeve116. It will be understood that relief bore148allows fluid to escape the chamber formed between projection152and end153as it contracts. In a similar fashion, relief bore142allows fluid to escape chamber143as it contracts during the shifting operation. After inner sleeve120has been shifted downhole, lock ring168may contract into the reduced external diameter of inner sleeve positioned adjacent the lock ring. Often, the pressure differential will be maintained for a short period of time at a pressure greater than that expected to cause the down hole shift to ensure that the shift has occurred. This is particularly important where more than one valve according to the present invention is used since once one valve has shifted to an open configuration in a subsequent step, a substantial pressure differential is difficult to establish.

The pressure differential is removed, thereby decreasing the force acting on shoulder186tending to move inner sleeve120down hole. Once this force is reduced or eliminated, spring180urges inner sleeve120into the open configuration shown inFIG. 6. Lock ring168is in a contracted state and no longer engages recess176such the ring now slides along the inner surface of the outer sleeve. In a preferred embodiment spring180has approximately 300 pounds of force in the compressed state inFIG. 7. However, varying amounts of force may be required for different valve configurations. Moreover, alternative sources other than a spring may be used to supply the force for opening. As inner sleeve120moves to the open configuration, relief bore154allows fluid to escape chamber155as it is contracted, while relief bores148and142allow fluid to enter the connected chambers as they expand.

Shown inFIG. 8Eis a cross-sectional, diagrammatic view taken along line A—A ofFIG. 8Cshowing the full assembly.

Although only a single preferred PACV embodiment of the invention has been shown and described in the foregoing description, numerous variations and uses of a PACV according to the present invention are contemplated. As examples of such modification, but without limitation, the valve connections to the production tubing may be reversed such that the inner sleeve moves down hole to the open configuration. In this configuration, use of a spring180may not be required as the weight of the inner sleeve may be sufficient to move the valve to the open configuration. Further, the inner sleeve may be connected to the production tubing and the outer sleeve may be slidable disposed about the inner sleeve. A further contemplated modification is the use of an internal mechanism to engage a shifting tool to allow tools to manipulate the valve if necessary. In such a configuration, locking ring168may be replaced by a moveable lock that could again lock the valve in the closed configuration. Alternatively, spring180may be disengageable to prevent automatic reopening of the valve.

Further, use of a PACV is contemplated in many systems. One such system is the ISO system is described in U.S. Pat. No. 5,609,204; the disclosure therein is hereby incorporated by reference. A tool shiftable valve, such as the one described in the above reference patent, may be utilized in conjunction with the production screens to accomplish the gravel packing operation. Such a valve could be closed as the crossover tool string is removed to isolate the formation. The remaining production valves adjacent the production screen may be pressure actuated valves such that inserting a tool string to open the valves is unnecessary.

In some embodiments of the invention, a ball holding service tool is used to drop a drop ball on an IFV or other object activated valve to manipulate the valve. Two different ball holding service tools are illustrated below.

Referring now toFIGS. 9A–11B, side views of a ball holding service tool800are shown. InFIGS. 9A–9B, the ball holding service tool800is shown in a run-in position with a ball808retained. InFIGS. 10A–10B, the ball holding service tool800is shown in a manipulation position with the ball808retained. InFIGS. 11A–11B, the ball holding service tool800is shown in a release position with the ball808being ejected from the tool.

The ball holding service tool800comprises basic components including a support string802, a lock sleeve804, a plunger806, and a drop ball808. The inside section802does not move. As shown inFIGS. 10A–10B, the lock sleeve804is held in a fixed, run-in, position relative to the support string802by a shear pin810. Further, the drop ball808is retained in the ball holding service tool800by lock dogs812. In the run-in position, the lock dogs812are held in a radial inward position by the lock sleeve804, so that the lock dogs812protrude into the interior of the support string802to support the drop ball808. The drop ball is held firmly against the lock dogs812by the plunger806, which is biased in the direction of the drop ball by a spring814.

Mandrel lock dogs805are mounted on the lock sleeve. The mandrel lock dogs805have a locking pin807which projects inward. When the lock sleeve804is in a close fitting bore (seeFIG. 10A), the mandrel lock dogs805are pushed inward which pushes the locking pins807into one of grooves809,811, or813on the support string802. When the locking pins807are in any one of the three grooves809,811, or813on the support string802, no relative movement is possible between the support string802and the lock sleeve804.

As shown inFIGS. 10A–10B, the ball holding service tool800is manipulated by sliding the lock sleeve804relative to the support string802. Of course, the shear pin810must be sheared to release the lock sleeve804. In the position shown, the lock sleeve804has moved relative to the support string802, but it has not moved a sufficient distance to release the lock dogs812. The lock sleeve804has an annular recess groove816with beveled shoulders.

The lock sleeve804is additionally controlled by pin815which extends into groove821in support string802. A laid-out side view of groove821is shown inFIG. 9C, wherein the pin815is shown in three separate positions within groove821. Groove821in support string802is configured so that the lock sleeve804must be reciprocated one or more times before the lock sleeve804can move far enough to align recess groove816with lock dogs812.

As shown inFIGS. 11A–11B, when the recess groove816becomes aligned with the lock dogs812, the lock dogs812are free to move radially outward. With the lock dogs812no longer constrained, the spring-loaded plunger806pushes the drop ball808through the lock dogs812so as to eject the drop ball808from the ball holding service tool800.

Referring now toFIGS. 12A–16E, side views of a second embodiment of a ball holding service tool800are shown with a cross over tool and packer. InFIGS. 12A–12E, the ball holding service tool800is shown in a run-in position with a drop ball808retained. InFIGS. 13A–13E, the ball holding service tool800is shown in a manipulation position with a dog retainer ring820sheared. InFIGS. 14A–14E, the ball holding service tool800is shown in a lock dog812release position. InFIGS. 15A–15E, the ball holding service tool800is shown in a ball retainer ring824shear position. InFIGS. 16A–16E, the ball holding service tool800is shown in a drop ball808release position.

In the run in configuration as shown inFIGS. 12A–12E, the drop ball808is secured firmly in the ball holding services tool800. The drop ball808is a ball with a long tail, wherein the tail is secured by the service tool. The ball holding service tool800has a holding barrel826into which the tail of the drop ball808is inserted. The service tool also has an ejector mandrel827which is spring loaded. In particular, the ejector mandrel827is biased toward the drop ball808by spring828. The drop ball808is held in its loaded position against the spring force by a plurality of balls829. The drop ball808has a groove in its tail, wherein the balls829extend into the groove to hold the drop ball808in the holding barrel826. The balls829are pushed into the groove of the drop ball808by a ball retainer ring824. The ball retainer ring824is secured to the holding barrel826by shear screws830. The ball holding service tool800also has a collet831which is squeezed into the crossover tool and packer. Because the collet831is made of flexible members, its outside diameter gets smaller as it is squeezed into the crossover tool and packer.

From the configuration shown inFIGS. 13A–13E, the ball holding service tool800is pulled further uphole to the position shown inFIGS. 14A–14E. In particular, the ball holding service tool800is brought to a position wherein the collet831is just above a shoulder835of the crossover tool and packer. As the ball holding service tool800is again run into the crossover tool and packer, the collet831remains stationery against the shoulder835so that the push ring833remains stationary relative to the downwardly moving holding barrel826. As shown inFIG. 14C, this relative movement moves the lock dogs812out from under the push ring833. The lock dogs812are biased in an uphole direction by a spring836such that upon being released by the push ring833, the lock dogs812pop out of the groove in the holding barrel826.

From the configuration shown inFIGS. 13A–13E, the ball holding service tool800is pulled further uphole to the position shown inFIGS. 14A–14E. In particular, the ball holding service tool800is brought to a position wherein the collet831is just above a shoulder835of the crossover tool and packer. As the ball holding service tool800is again run into the crossover tool and packer, the collet831remains stationery against the shoulder835so that the push ring833remains stationary relative to the downwardly moving holding barrel826. As shown inFIG. 14C, this relative movement moves the lock dogs812out from under the push ring833. The lock dogs812are biased in an uphole direction by a spring836such that upon being released by the push ring833, the lock dogs812pop out of the groove in the holding mandrel826.

Once the lock dogs812are released, the ball holding service tool800is pulled uphole until the lock dogs812are above the shoulder835of the crossover tool and packer. The ball holding service tool800is then run downhole into the crossover tool and packer, to the position shown inFIGS. 15A–15E. In this position, the lock dogs812engage a smaller shoulder837of the crossover tool and packer. This smaller shoulder837holds the lock dogs812stationery while the crossover tool continues downhole. The lock dogs812work against the ball retaining ring824as shown inFIG. 15E. Shear screws838extend from the ball retaining ring824into the holding barrel826. As the holding barrel826continues downhole, so that the shear screws838are eventually sheared.

The mandrel826continues to move downhole to a position shown inFIGS. 16A–16E. In this position, the ball retainer ring824is moved relative to the holding barrel826such that a portion of the ball retainer ring824having a relatively larger inside diameter is positioned over the balls829. Further, the lock dogs812position themselves radially inward behind a shoulder839to retain the ball retaining ring824in its new position. In this configuration, the balls829are free to move radially outward so that they are no longer in the groove of the tail section of the drop ball808. The energy stored in the spring828is then released to drive the ejector mandrel827into the holding barrel826to expel the drop ball808from the end of the holding barrel826(seeFIG. 16E).

FIGS. 16F–16Hare schematic cross-sectional views of another embodiment of an object holding service tool that incorporates features of the previous ball holding embodiments. The object holding service tool holds and releases the ball to manipulate one or more of valves, nominated herein as an object activated valve (OAV). Such valves include, for example, the IFV described in reference toFIGS. 18A–20C. Other valves that can be actuated by a “dropped” object in a well bore, whether pressurized by fluid or not, are known those with ordinary skill in the art and are included herein.

FIG. 16Fillustrates this embodiment in a closed position with drop ball sealing a flow path in the tool.FIG. 16Gillustrates the embodiment ofFIG. 16Fin a released condition with flow path open. The embodiment can be used advantageously in conjunction with the OAVs in the various well bore procedures and operations, and related systems and methods, described herein. The object holding service tool can be coupled to the various systems and other tools either temporarily or in relative permanence to remain in the wellbore. The term “coupled,” “coupling”, and like terms are used broadly herein and can include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, a functional member with another, directly or indirectly through intervening members. Further, a given system can include more than one or more object holding service tools as may be desired to activate one or more valves.

InFIG. 16F, an object holding service tool can be used to retain the drop ball. The tool can be included with a crossover tool, such as shown inFIGS. 12A–16E; wireline and coiled tubing tools; downhole plugs, more particularly shown inFIG. 16H; mechanical sleeves that can be used to manually actuate the release of the drop ball, or other tools that can temporarily retain a drop ball.

The object holding service tool850generally includes a holding barrel826. The holding barrel826can be engaged with the tool, formed integrally therewith, or otherwise coupled to the tool. The holding barrel826includes an internal bore852that can be slidably and sealingly engaged with the drop ball808. However, in this embodiment, the drop ball808is releasably engaged with the holding barrel826by one or more shear screws834, such as shown inFIGS. 16F–16H, one or more split rings834a, such as shown inFIG. 161, or other restraining devices. Further, the holding barrel826includes one or more seal grooves840,842. One or more corresponding seals844,846disposed in the seal grooves840,842act to sealingly engage the drop ball808, such as in a tail section808a, with the holding barrel826. Alternatively, the grooves could be formed in the drop ball808. Further, the holding barrel can remain fixedly position relative to other parts of the object holding service tool850or move relative to the tool for other purposes. The release of the drop ball is generally independent of the position of the holding barrel826relative to other portions of the tool in this embodiment. Further, object holding service tool and the releasable drop ball can restrict bidirectional flow upstream and downstream in contrast to some flow restrictions in the field.

The drop ball808can be inserted into the holding barrel826of the object holding service tool850in an initial “run in” condition. The flow path854through the central bore of the tool is restricted by the drop ball808. Various operations can be performed using the tools and procedures described herein. When a portion of the operations uses the central flow path854and the drop ball808is to be released, the central flow path is pressurized to a pressure that creates a force on an area856or other areas of the drop ball sufficient to shear or otherwise cause the one or more restraining devices restraining the drop ball to release the drop ball. The drop ball808is released and is forced to another location, generally downstream, by the pressure. The drop ball can engage an OAV described herein to close, open, or otherwise affect the valve.

The object holding service tool850can include a tool, such as a plug, that can temporarily hold a drop ball, such as shown inFIG. 16Hand described above. The plug can comprise a packer plug, such as an equalizing packer plug having single or dual valves for equalizing, the basis of which are known in the art. The tool can include the holding barrel826separate or formed integrally therewith. In some embodiments, the holding barrel826can be a portion of the material forming the plug with the internal bore852formed therein.

The plug can be placed in position at a selected location such as an internal bore of a packer. At an appropriate time, the central flow path854can be pressurized to exert pressure on the drop ball808and force the drop ball out of the sealed engagement with the internal bore852. The drop ball can then be used to engage an OAV.

FIG. 16Jillustrates a cross sectional view of a drop ball808and a holding barrel826in an alternative embodiment during a fracturing operation. A circulating valve860is coupled to the holding barrel826on one end of the holding barrel and a seal spacer862is coupled to the holding barrel on the other end. An assembly, such as a packer864, is generally disposed external to the holding barrel826and seal spacer862at different stages of the operation. The packer includes a seal bore866that acts as a sealing surface to various assemblies that are manipulated in the well at different stages of operations. The circulating valve860includes a port868that allows fluid, such as fracturing carrier fluid, to flow from the flow path892out through a circulating port872into the annulus874above the packer.

The seal spacer862includes a seal876. The seal876allows sealing of the holding barrel and related assemblies at different states of operation. When sealed, fluid in an upstream portion of the well can build to a sufficient pressure to sever a shear screw holding the drop ball, as described below.

The drop ball808is coupled to the holding barrel826with a shear screw834or other restraining device. A port880is formed in the holding barrel to allow fluid communication between a flow path890and the outside surface of the drop ball808. The drop ball can include at least two cross sectional areas, a small portion882and a large portion884. A first seal886is disposed on the small portion882between the drop ball and the holding barrel and a second seal888is disposed on the large portion884in like fashion on the distal side of the shear screw834from the first seal.

In the fracturing operation, the crossover tool is positioned in the packer864so that seals (not shown) in the crossover tool seal in the seal bore866of the packer upstream of the circulating port868. The circulating port is open and allows fluid to flow therethrough from the flow path892into the bore870. The holding barrel826and seal spacer862are disposed below the seal bore866of the packer and does not effectuate a seal therewith. Thus, fracturing return fluid flows above the holding barrel826and seal876of the seal spacer in the flow path892and around to the downstream portion of the drop ball, so that the pressures upstream and downstream from the holding barrel and drop ball are balanced.

Pressure in the bore870upstream of the drop ball808is substantially equivalent to the pressure in the bore below the drop ball during the fracturing operation. Further, the drop ball808is restrained in position in the holding barrel826using the shear screw834. Thus, the combination of the equivalent pressures and location of seals offers a safety feature to restrict inadvertent deployment of the drop ball caused by unequal pressures.

FIG. 16Killustrates the embodiment ofFIG. 16Jin a reversing stage of operations. Similar elements are similarly labeled. The reversing process is generally performed to flush out extraneous proppant left from the fracturing operation by reversing the flow path of fluid upstream of the formation. Generally, the crossover tool is pulled up in the well to disengage the packer seal bore866which closes the circulating valve860and fluid flows down the annulus874, into the fracturing port (not shown), and upward through the tooling to the well surface. The seal876downstream of the holding barrel for the drop ball808is still positioned below the seal bore866of the packer864. The pressure in the annulus874is isolated by seals or can be generally substantially equal to the pressure in the bore870adownstream of the drop ball seal888. Since seal876is not engaged in a seal bore, pressure is partially balanced around the drop ball808. Thus, no pressure in the annulus874acts on the large portion884of the drop ball to cause the holding barrel826to release the drop ball. This aspect allows the drop ball to be controlled during the reversing process.

However, if an operator desired to cause the drop ball to release in the reversing stage, the operator could pressurize the bore to a pressure sufficient to exert a force upstream of the seal886on the small portion882of the drop ball that is exposed to the pressurized fluid. The pressure will be generally need to be higher with the small portion882compared to the large portion884of the drop ball808. The force severs the shear screw834and the drop ball is released to a downstream location.

FIG. 16Lillustrates a cross sectional schematic view of the embodiment ofFIGS. 16J,16K in a low pressure launch position. Similar elements are similarly labeled. The holding barrel826can be moved toward the packer864relative toFIG. 16K, so that the seal876sealingly engages the seal bore866. Fluid can flow in the bores870,870aand in various internal flow paths such as flow path890and892of the packer864. The fluid is restricted from flowing past the seal876with the engagement of the seal bore866and can be pressurized upstream from the seal. The fluid external to the holding barrel826and internal to the seal bore866in the flow path890can enter port880and flow to the large portion884of the drop ball808. The seal888downstream of port880restricts further fluid flow and allows the pressurized fluid to exert a force on the large portion884. Also, pressure in the flow path890is free to enter the cross over tool into bore870and act on the seal886which assists the seal888. Sufficient force severs the shear screw834and allows the holding barrel826to release the drop ball808.

Another valve used in various embodiments of the present invention is the IFV. Three different embodiments of the IFV are illustrated herein.

Referring toFIGS. 17A–17C, side views of a first embodiment of the IFV are shown, wherein the IFV1000is shown in two different configurations on each side of the center line. Above the center line, the valve is shown in an open configuration and below the line, the valve is shown in a closed configuration. The IFV1000comprises basic components including: a string1002, a sliding sleeve1004, and a basket1007.

The string1002comprises several pipe sections made-up to form a single pipe string. The string1002also has a string port section1012which allows fluid to flow between the outside diameter and the inside diameter. The sliding sleeve1004is positioned concentrically within the string1002. The sliding sleeve1004has seal section1016and a sleeve port section1017. The basket1007has holes1021in its lower end to allow fluid to flow between the inside diameter of the sliding sleeve1004above the basket1007and the inside diameter of the sliding sleeve1004below the basket1007. The basket1007also has a seat upon which a drop ball808may land.

In the open configuration (shown above the centerline), the sleeve port section1017is positioned adjacent the string port section1012. The sliding sleeve1004is held in this position by shear screws1013which extend between the sliding sleeve1004and the string1002. Also, in the open configuration of the IFV, the basket1007is held within the sliding sleeve1004by lock dogs1009which extend from the sliding sleeve1004into a retaining groove1011in the basket1007. The lock dogs1009are held radially inward by the inside diameter of the string1002.

The IFV1000is closed by dropping a drop ball808into the valve. The drop ball808lands on the seat1022in the basket1007. The drop ball808mates with the seat1022to restrict fluid flow from the inside diameter above the valve, down through the basket1007. As fluid pressure increases in the inside diameter above the drop ball808, a downward force is exerted on the basket1007. This downward force is transferred from the basket1007to the sliding sleeve1004through the lock dogs1009. The downward force on the sliding sleeve1004becomes great enough to shear the shear screws1013to release the sliding sleeve1004from the string1002. Upon shear of the shear screws1013, the sliding sleeve1004and basket1007travel together down the string1002to close the valve. In particular, the seal section1016becomes positioned over the string port section1012to completely restrict the flow of fluid through the string port section1012. Seals1023are located above and below the string port section1012to insure the integrity of the valve.

The sliding sleeve1004continues its downward movement until the lock dogs1009engage a release groove1010and the sliding sleeve1004bottoms out on shoulder1024. The sliding sleeve1004is held in the closed position by a ring1025(seeFIG. 17A) which is positioned within a groove1026in the string1002. Because the leading end of the sliding sleeve1004is tapered to sting into the ring1025. The sliding sleeve1004is pushed into the ring1025until the ring snaps into a groove1027in the sliding sleeve1004. The ring1025is retained in both grooves1026and1027to prevent the sliding sleeve1004from moving back into the open position.

When the lock dogs1009engage the release groove1010of the string1002, the lock dogs1009are released to move radially outward. The lock dogs1009move radially outward from a position protruding into the basket1007, through the sliding sleeve1004, and to a position protruding into the release groove1010. This radial movement of the lock dogs1009releases the basket1007from the sliding sleeve1004to allow both the basket1007and drop ball808to fall freely out the bottom of the IFV.

Referring toFIGS. 18A–19C, side views of a second embodiment of an IFV are shown, wherein the valve is in an open configuration inFIGS. 19A–19Cand a closed configuration inFIGS. 18A–18C. The IFV1000comprises basic components including: a string1002and a sliding sleeve1004. The string1002comprises several pipe sections made-up to form a single pipe string. The string1002has a slip bore1006immediately adjacent a release groove1010, wherein the slip bore1006and the release groove1010are separated by a shoulder1008. Thus, the internal radius of the slip bore1006is smaller than the internal radius of the release groove1010such that the difference is the height of the shoulder1008. The string1002also has a string port section1012having a plurality of lengthwise ports evenly spaced around the string1002.

The sliding sleeve1004of the IFV1000is positioned coaxially within the string1002. The sliding sleeve1004is basically comprised of a plurality of cantilever fingers1014, a middle seal section1016, a sleeve port section1017, and an end seal section1018. The cantilever fingers1014extend from one end of the middle seal section1016and are evenly spaced from each other. Each cantilever finger1014has a spreader tip1015at its distal end. In the open configuration, shown inFIGS. 19A–19C, the spreader tips1015rest on the slip bore1006of the string1002, and in the closed position, the spreader tips1015rest in the release groove1010of the string1002. When the spreader tips1015rest on the slip bore1006, the spreader tips define a relatively smaller diameter sufficient to form a seat for catching a drop ball808. The middle seal section1016has a cylindrical outer surface for mating with annular seals1019and1020, which are fixed to the string1002above and below the string port section1012, respectively. In the open position, the middle seal section1016mates only with the annular seal1019, but in the closed position, the middle seal section1016mates with both annular seal1019and1020. Further, in the closed position, the middle seal section1016spans the string port section1012(seeFIGS. 18A and 18B). The sleeve port section1017has a plurality of lengthwise ports evenly spaced around the sliding sleeve1004. When the IFV1000is in an open configuration, the sleeve port section1017is adjacent the string port section1012. The end seal section1018has a cylindrical outer surface for mating with annular seal1020when the valve is in an open configuration. To hold the IFV1000in the open position, shear pins1013(seeFIG. 19B) are fastened between the spreader tips1015and the slip bore1006.

The IFV1000is reconfigured from the open configuration to the closed configuration by dropping a drop ball808from a ball holding service tool800onto the seat defined by the spreader tips1015of the IFV1000. The outside diameter of the drop ball808is larger than the inside diameter of a circle defined by the interior of the spreader tips1015, when the spreader tips1015are seated in the slip bore1006. Thus, when the drop ball808falls on the spreader tips1015, the ball is supported by the spreader tips1015and does not pass therethrough. The weight of the drop ball and fluid pressure behind the drop ball808combine to produce sufficient force to the spreader tips1015to shear the shear pins1013. Fluid pressure behind the drop ball808then pushes the sliding sleeve1004until the middle seal section1016mates with both annular seals,1019and1020, and spans the string port section1012. At this position, the spreader tips1015clear the shoulder1008and snap into the release groove1010(seeFIG. 18B). Because the internal radius of the slip bore1006is smaller than the internal radius of the release groove1010, the inside diameter of a circle defined by the interior of the spreader tips1015becomes larger as the spreader tips snap into the release groove1010. The cantilever fingers1014are prestressed to bias the spreader tips1015radially outward. The circle defined by the interior of the spreader tips1015becomes large enough to release the drop ball808so that the drop ball808passes through the IFV1000and down into the rat hole of the well (seeFIG. 18A). The IFV1000becomes locked in the closed configuration because the shoulder1008prevents the spreader tips1015from reversing direction once they have snapped into the release groove1010.

An alternate embodiment of an IFV1000is shown inFIGS. 20A–20C. This embodiment is very similar to that illustrated above. InFIGS. 20A–20C, the configuration illustrated above the center line is an open configuration and that illustrated below the center line is a closed configuration. As before, this IFV1000has a string port section1012in a string1002. However, in this embodiment, the sliding sleeve1004is basically comprised of a plurality of cantilever fingers1014and a seal section1016. The cantilever fingers1014extend from one end of the seal section1016and are evenly spaced from each other. Each cantilever finger1014has a spreader tip1015at its distal end. In the open configuration, shown above the center line, the spreader tips1015rest on the slip bore1006of a tube held within the string1002. To hold the IFV1000in the open position, shear screws1013(seeFIG. 20B) are fastened between the spreader tips1015and the tube defining the slip bore1006. In the open position, the seal section1016and annular seals1019and1020are positioned above the string port section1012.

In the closed position, the spreader tips1015rest in the release groove1010of the string1002. When the spreader tips1015rest on the slip bore1006, the spreader tips define a relatively smaller diameter sufficient to form a seat for catching a drop ball808. The seal section1016has a cylindrical outer surface with annular seals1019and1020fixed to the sliding sleeve1004at each end of the seal section1016. In the closed position, the seal section1016spans the string port section1012and annular seal1019and1020contact the string1002on either side to ensure the integrity of the closed valve. The sleeve port section1017has a plurality of lengthwise ports evenly spaced around the sliding sleeve1004.

To manipulate the IFV from the open configuration to the closed configuration, a drop ball808is used as described with reference to the IFV embodiment illustrated inFIGS. 19A–19C.

FIGS. 20D–20Fillustrate a cross sectional schematic of a drop ball808engagement and actuation of a valve1005. The upper portion of these figures illustrates a drop ball in engagement with an open valve having a sliding sleeve1004with a collet assembly1028. The lower portion illustrates a closed valve after the drop ball has actuated the valve through movement of the sliding sleeve1004.

The valve1005can be coupled downstream of a holding barrel with a drop ball, described above. The valve can be, but is not limited to, a sliding sleeve valve, such as the IFV1000described inFIGS. 18A–20B. The holding barrel826can be, but is not limited to, the holding barrels described inFIGS. 12A–16N. The valve can include a slip bore1006and a port section1012. The slip bore1006can be formed in the inner surfaces of the valve for slidably engaging internal structures of the valve. The port section1012can allow fluid to flow between an internal bore870aof the valve and an external annulus874formed between the valve and well casing.

The valve1005includes a sliding sleeve1004disposed inward of the slip bore1006. The sliding sleeve generally includes a seal section1016, a sleeve port section1017coupled to the seal section, and an end seal section1018coupled to the sleeve port section. The valve also includes a collet assembly1028coupled to the sliding sleeve1004and flexibly and outwardly engaged with the internal surfaces of the slip bore1006. Generally, the collet assembly1028includes cantilever fingers1014biased outwardly. The cantilever fingers1014include spreader tips1015used to catch and release the drop ball808. The collet assembly1028is restrained with the valve by a shear screw1013or other restraining device.

Fluid flow through the sliding sleeve1004can be controlled by selective engagement with seals1019a,1019bdisposed between an outer surface of the sliding sleeve1004and internal surfaces of the valve1005. The seals1019a,1019bcan be longitudinally separated by a piston1030coupled to the sliding sleeve1004. The piston1030allows a force to be generated by applying a pressurized fluid over an area formed by an inner seal surface1038of the valve1005minus an area formed by an outer seal surface1040of the sliding sleeve1004. A relief port1036formed in the valve allows fluid trapped between inner surfaces of the valve and outer surfaces of the sliding sleeve to escape upon actuation and closure of the valve.

A lock ring1032is disposed internal to the valve and can be used to restrict reverse movement of the sliding sleeve1004. The lock ring1032can engage external surfaces of a portion1034of the sliding sleeve1004. For example, the reverse movement can be restricted by grooves1035in the external surfaces of the portion1034engaging corresponding internal surfaces1033on the lock ring.

The port section1012includes ports1012a. Generally, ports1012ain the port section1012allow fluid flow between the bore870aand the annulus874when aligned with corresponding ports1017ain the sleeve port section1017of the sliding sleeve1004.

A seal1020is disposed downstream of the port section1012between the outer surfaces of the sliding sleeve1004and the inner surfaces of the valve. The seal1020is used to seal the sliding sleeve1004as it traverses in the valve. A shifting profile1042is coupled to the sliding sleeve and forms a projection for a mechanical engagement with a tool (not shown) to assist in actuating the valve, if the valve is not shifted through the drop ball, as described below.

In operation, the drop ball808is released from the holding barrel described in various figures above, and travels downstream to the valve1005. The drop ball sealingly engages the collet assembly1028at the spreader tips1015and allows pressurized fluid upstream of the drop ball to create a force on the collet assembly in combination with any inertia from the drop ball released from the holding barrel. A sufficient force severs the shear screw1013to allow the sliding sleeve1004to move longitudinally downstream. As the sliding sleeve1004moves downstream, the lock ring1032engages the portion1034of the sliding sleeve to restrict reverse travel. Fluid, trapped in the space between the outer surface of the sliding sleeve1004and the inner surfaces of the valve, is allowed to exit through the relief port1036. The sleeve port section1017of the sliding sleeve1004becomes offset with the port section1012in the valve and flow is restricted.

With sufficient travel, the collet assembly1028enters a portion of the valve assembly having a larger internal dimension, such as a release groove1010. Further, the pressurized fluid is allowed to flow into the area1044upstream of the piston1030. The piston1030is forced to move downstream to further assist in moving the sliding sleeve1004so that the valve1005closes. The collet assembly1028is allowed to spread outwardly and release the drop ball808to a downstream portion of the well, so as to not further restrict flow in the valve1005.

As shown in the lower portion ofFIGS. 20D–20F, after the valve is actuated to a closed position, the sleeve port section1017is disposed at least partially downstream of the seal1020. The seal1019bis disposed upstream of the port section1012of the valve. The sliding sleeve1004forms an inner wall to the valve in the vicinity of the port sections1012,1017. Thus, fluid flow is restricted between the bore870aand the annulus874of the well and the valve is “closed”. The engagement between the lock ring1032and the sliding sleeve1004assists in maintaining the closed position.

In multi-zone wells, the above assemblies can be assembled to the completion string of the well in the various production zones. A similar procedure could be followed for each zone that is to be closed. For example and without limitation, a lower zone could be closed and then an upper zone closed by a second system of the drop ball and valve.

Referring toFIG. 21, a side view is shown of a fixed isolation string with a PACV and an IFV. The isolation string1100has a packer1101at its top for securing and sealing the top of the isolation string1100in a well casing. It also has a packer1102at its bottom for sealing the bottom of the isolation string1100. The string further comprises cross-over ports1103for use during a gravel pack operation. A portion of a production tube is shown stung into the isolation string1100for seating in a seal bore1104. A double-pin sub1105is made-up to the string below the seal bore1104. A screen pipe1106and an isolation pipe1107are made-up to the bottom of the double-pin sub1105. The bottom of the screen pipe1106is made up to the packer1102. Further, the isolation pipe1107is stung into and landed in a seal bore of the packer1102to seal the bottom of the isolation pipe1107. The screen pipe1106has a production screen1108around a perforated base pipe section1109. The isolation pipe1107has two valves: a PACV1110and an IFV1111.

The isolation system illustrated inFIG. 21may be used to complete a well. The isolation string1100is run-in the well on a cross-over service tool and set in the casing with the production screen1108adjacent perforations in the casing. When the isolation string1100is run-in the well, the PACV1110is closed and the IFV1111is open. A gravel pack operation is performed by circulating a slurry through cross-over ports1103to deposit the gravel pack in the annulus between the production screen1108and the casing, while the filtered suspension fluid is circulated through the open IFV1111. When the gravel pack operation is complete a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1111to close the valve and isolate the gravel packed production zone. The service tool is then released from the isolation string1100and withdrawn from the well. A production string is then run-in the well and stung into the isolation string1100. Pressure differential between the inner bore and the annulus is then used to open the PACV1110to bring the well into production.

Referring toFIG. 22, a side view is shown of a screen wrapped isolation string with a PACV and an IFV. The isolation string1200has a packer1201at its top for securing and sealing the top of the isolation string1200in a well casing. It also has a packer1202at its bottom for sealing the bottom of the isolation string1200. The string further comprises cross-over ports1203for use during a gravel pack operation. A portion of a production tube is shown stung into the isolation string1200for seating in a seal bore1204. A safety shear sub1205is made-up to the string below the seal bore1204. A blank pipe1206is made-up to the bottom of the safety shear sub1205. The bottom of the blank pipe1206is made up to the packer1202. The blank pipe1206has two valves: a PACV1210and an IFV1211. A wire wrap production screen1208is wrapped around the blank pipe1206, the PACV1210, and the IFV1211.

The isolation system illustrated inFIG. 22may be used to complete a well. The isolation string1200is run-in the well on a cross-over service tool and set in the casing with the production screen1108adjacent perforations in the casing. The cross-over service tool is not shown inFIG. 22, but it has a ball drop service tool800as shown inFIGS. 9A–16E. When the isolation string1200is run-in the well, the PACV1210is closed and the IFV1211is open. A gravel pack operation is performed by circulating a slurry through cross-over ports1203to deposit the gravel pack in the annulus between the production screen1208and the casing, while the filtered suspension fluid is circulated through the open IFV1211. When the gravel pack operation is complete a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1211to close the valve and isolate the gravel packed production zone. The service tool is then released from the isolation string1200and withdrawn from the well. A production string is then run-in the well and stung into the isolation string1200. Pressure differential between the inner bore and the annulus is then used to open the PACV1210to bring the well into production.

Referring toFIG. 23, a side view is shown of a lower zone isolation string with a RFV and an IFV. The isolation string1300has a packer1301at its top for securing and sealing the top of the isolation string1300in a well casing. It also has a packer1302at its bottom for sealing the bottom of the isolation string1300. The string further comprises cross-over ports1303for use during a gravel pack operation. A portion of a production tube is shown stung into the isolation string1300for seating in a seal bore1304. A safety shear sub1305is made-up to the string below the seal bore1304. A RFV1312is made up to the bottom of the safety shear sub1305and is pressure activated to open and allow fluids to flow radially from an annulus below the RFV1312. Both a screen pipe1306and an isolation pipe1307are made-up to the bottom of the RFV1312. The bottom of the screen pipe1306is made up to the packer1302. Further, the isolation pipe1307is stung into and landed in a seal bore of the packer1302to seal the bottom of the isolation pipe1307. The screen pipe1306has a production screen1308around a perforated base pipe section1309. The isolation pipe1307has an IFV1311.

The isolation system illustrated inFIG. 23may be used to complete a well. The isolation string1300is run-in the well on a cross-over service tool and set in the casing with the production screen1308adjacent perforations in the casing. The cross-over service tool is not shown inFIG. 23, but it has a ball drop service tool800as shown inFIGS. 9A–16E. When the isolation string1300is run-in the well, the RFV1312is closed and the IFV1311is open. A gravel pack operation is performed by circulating a slurry through cross-over ports1303to deposit the gravel pack in the annulus between the production screen1308and the casing, while the filtered suspension fluid is circulated through the open IFV1311. When the gravel pack operation is complete, a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1311to close the valve and isolate the gravel packed production zone. The service tool is then released from the isolation string1300and withdrawn from the well. A production string is then run-in the well and stung into the RFV1312. Pressure differential between the inner bore and the annulus is then used to open the RFV1312to bring the well into production.

Referring toFIG. 24, a side view is shown of a dual-zone, selective isolation string with AFV, a RFV, and two IFV. The isolation string1400has a top packer1401at its top for securing and sealing the top of the isolation string1400in a well casing. It also has a bottom packer1402at its bottom for sealing the bottom of the isolation string1400. Further, the string has a middle packer1413for sealing the annulus between upper and lower zones. The string further comprises cross-over ports1403aand1403bfor use during gravel pack operations. A safety shear sub1405ais made-up to the string below a seal bore1404a. An AFV1414is made up to the bottom of the safety shear sub1405aand is pressure activated to open and allow fluids to flow from an annulus below the valve1414to an annulus above. A portion of a production tube is shown stung into the AFV1414. Both a screen pipe1406aand an isolation pipe1407aare made-up to the bottom of the AFV1414. The bottom of the screen pipe1406ais stung into and landed out in a seal bore1404bbelow the middle packer1413. Further, the isolation pipe1407ais stung into and landed in a seal bore of a RFV1412to seal the bottom of the isolation pipe1407a. The screen pipe1406ahas a production screen1408aaround a perforated base pipe section1409a. The isolation pipe1407ahas a IFV1411a. A safety shear sub1405bis made-up to the string below the seal bore1404b. The RFV1412is made up to the bottom of the safety shear sub1405band is pressure activated to open and allow fluids to flow radially from an annulus below the valve1412to the inner bore of the valve. Both a screen pipe1406band an isolation pipe1407bare made-up to the bottom of the RFV1412. The bottom of the screen pipe1406bis stung into and landed out in the lower packer1402. Further, the isolation pipe1407bis stung into and landed in a seal bore of the lower packer1402to seal the bottom of the isolation pipe1407b. The screen pipe1406bhas a production screen1408baround a perforated base pipe section1409b. The isolation pipe1407bhas a IFV1411b.

The isolation system illustrated inFIG. 24may be used to complete two production zones in a well. The isolation string1400is run-in the well on a cross-over service tool in two separate trips. The lower section1400bof the isolation string1400is run-in the well and set in the casing with the production screen1408badjacent perforations for the lower zone in the casing. The cross-over service tool is not shown inFIG. 24, but it has a ball drop service tool800as shown inFIGS. 9A–16E. When the upper section1400aof the isolation string1400is run-in the well, the RFV1412is closed and the IFV1411bis open. A gravel pack operation is performed by circulating a slurry through cross-over ports1403bto deposit the gravel pack in the annulus between the production screen1408band the casing, while the filtered suspension fluid is circulated through the open IFV1411b. When the gravel pack operation is complete, a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1411bto close the valve and isolate the gravel packed lower production zone. The service tool is then released from the lower section1400bof the isolation string1400and withdrawn from the well.

In a second trip into the well, the upper section1400aof the isolation string1400is run-in the well and set in the casing with the production screen1408aadjacent perforations for the upper zone in the casing. The distal end of the upper section1400ais stung into the lower section1400b. In particular, the screen pipe1406ais stung into the middle packer1413and the isolation pipe1407ais stung into the RFV1412. The cross-over service tool is not shown inFIG. 24, but it has a ball drop service tool800as shown inFIGS. 9A–16E. Of course, before running into the well for this second trip, the ball drop service tool800is charged with a second drop ball808. When the upper section1400aof the isolation string1400is run-in the well, the AFV1414is closed and the IFV1411ais open. A gravel pack operation is performed by circulating a slurry through cross-over ports1403ato deposit the gravel pack in the annulus between the production screen1408aand the casing, while the filtered suspension fluid is circulated through the open IFV1411a. When the gravel pack operation is complete, a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1411ato close the valve and isolate the gravel packed production zone. The service tool is then released from the upper section1400aof the isolation string1400and withdrawn from the well.

A production string is then run-in the well and stung into the AFV1414. Pressure differential between the inner bore and the annulus is then used to open the AFV1414and RFV1412to bring the well into production. The upper zone production flows through the annulus on the outside of the production string to the surface. The lower zone production flows through the inner bore of the production string to the surface.

Referring toFIG. 25, a side view is shown of a dual-zone, selective isolation string with an AFV and an IFV for the upper zone, and an IFV and a PACV for the lower zone. The isolation string1500has a top packer1501at its top for securing and sealing the top of the isolation string1500in a well casing. It also has a bottom packer1502at its bottom for sealing the bottom of the isolation string1500. Further, the string has a middle packer1513for sealing the annulus between upper and lower zones. The string further comprises cross-over ports1503aand1503bfor use during gravel pack operations. A safety shear sub1505ais made-up to the string below a seal bore1504a. An AFV1514is made up to the bottom of the safety shear sub1505aand is pressure activated to open and allow fluids to flow from an annulus below the valve1514to an annulus above. A portion of a production tube is shown stung into the AFV1514. Both a screen pipe1506aand an isolation pipe1507are made-up to the bottom of the AFV1514. The bottom of the screen pipe1507is stung into and landed out in a seal bore1504bbelow the middle packer1513. Further, the isolation pipe1507is stung into and landed in a seal bore of the screen pipe1506ato seal the bottom of the isolation pipe1507. The screen pipe1506ahas a production screen1508aaround a perforated base pipe section1509. The isolation pipe1507has an IFV1511a. A safety shear sub1505bis made-up to the string below the seal bore1504b. A blank screen pipe1506is made-up to the bottom of the safety shear sub1505b. The bottom of the blank screen pipe1506is made up to the lower packer1502. The blank screen pipe1506has two valves: a PACV1510and an IFV1511b. A wire wrap production screen1508bis wrapped around the blank screen pipe1506b, the PACV1510, and the IFV1511b.

The isolation system illustrated inFIG. 25may be used to complete a well. The isolation string1500is run into the well in two separate trips. The lower section1500bof the isolation string1500is run-in the well and set in the casing with the production screen1508badjacent perforations for the lower zone in the casing. The lower section1500bof the isolation string1500is run-in the well on a cross-over service tool and set in the casing with the production screen1508badjacent the lower zone perforations in the casing. The cross-over service tool is not shown inFIG. 25, but it has a ball drop service tool800as shown inFIGS. 9A–16E. When the lower section1500bis run-in the well, the PACV1510is closed and the IFV1511bis open. A gravel pack operation is performed by circulating a slurry through cross-over ports1503bto deposit the gravel pack in the annulus between the production screen1508band the casing, while the filtered suspension fluid is circulated through the open IFV1511b. When the gravel pack operation is complete a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1511bto close the valve and isolate the gravel packed lower production zone. The service tool is then released from the lower section1500bof the isolation string1500and withdrawn from the well.

In a second trip into the well, the upper section1500aof the isolation string1500is run-in the well and set in the casing with the production screen1508aadjacent perforations for the upper zone in the casing. The distal end of the upper section1500ais stung into the lower section1500b. In particular, the screen pipe1506ais stung into the middle packer1513and the isolation pipe1507is already stung into the distal end of the isolation pipe1507. The cross-over service tool is not shown inFIG. 25, but it has a ball drop service tool800as shown inFIGS. 9A–16E. Of course, before running into the well for this second trip, the ball drop service tool800is charged with a second drop ball808. When the upper section1500aof the isolation string1500is run-in the well, the AFV1514is closed and the IFV1511ais open. A gravel pack operation is performed by circulating a slurry through cross-over ports1503ato deposit the gravel pack in the annulus between the production screen1508aand the casing, while the filtered suspension fluid is circulated through the open IFV1511a. When the gravel pack operation is complete, a drop ball808is dropped from the service tool having a ball holding service tool800(seeFIGS. 9A–16E). The drop ball808operates on the IFV1511ato close the valve and isolate the gravel packed upper production zone. The service tool is then released from the upper section1500aof the isolation string1500and withdrawn from the well.

A production string is then run-in the well and stung into the AFV1514of the isolation string1500. Pressure differential between the inner bore and the annulus is then used to open the AFV1514and the PACV1510to bring the well into production. Production from the upper zone flows through the annulus around the production pipe and production from the lower zone flows through the inner bore of the production pipe.

Many of the components described herein are generally available from industry sources as known to persons of skill in the art. For example, packers, cross-over ports, double-pin subs, screen pipe, isolation pipe, production screens, and other components which are generally known to persons of skill in the art may be used in the various embodiments of the present invention.

While the foregoing is directed to various embodiments of the present invention, other and further embodiments can be devised without departing from the basic scope thereof Further, the various methods and embodiments of the invention can be included in combination with each other to produce variations of the disclosed methods and embodiments. Discussion of singular elements can include plural elements and vice-versa. Further, the use of any numeric quantities herein, particularly regarding the claims, such as “a” or “the”, includes at least such quantity and can be more. The use of a term in a singular tense is not limiting of the number of items. Any directions shown or described such as “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and other directions and orientations are described herein for clarity in reference to the figures and are not to be limiting of the actual device or system or use of the device or system. The device or system can be used in a number of directions and orientations.

The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions. Additionally, any headings herein are for the convenience of the reader and are not intended to limit the scope of the invention.

Further, any references mentioned in the application for this patent as well as all references listed in any information disclosure originally filed with the application are hereby incorporated by reference in their entirety to the extent such may be deemed essential to support the enabling of the invention. However, to the extent statements might be considered inconsistent with the patenting of the invention, such statements are expressly not meant to be considered as made by the Applicants.