In downhole tubular strings, hydraulic pressure may be used to actuate various components. For example, packers may be pressure set, sleeve valves may be provided that are hydraulically moveable to open ports.
Although hydraulically actuable components are useful, difficulties can arise when there is more than one hydraulically actuable component to be separately actuated. In a system including pressure set packers and sleeve valves for tubular ports, difficulties have occurred when attempting to open the sleeve valves after the packers have been set.
Also, difficulties have occurred in strings where it is desired to run in the string with all ports closed by hydraulically actuable sleeve valves and then to open the sleeves at a selected time. If one port opens first, it is difficult to continue to hold pressure to move the sleeves from the remaining ports.
In accordance with a broad aspect of the present invention, there is provided a hydraulically actuable sleeve valve comprising: a tubular segment including a wall defining therein an inner bore; a port through the wall of the tubular segment; a sleeve supported by the tubular segment and installed to be axially moveable relative to the tubular segment from a first position covering the port to a second position and to a third position away from a covering position over the port, the sleeve including a first piston face open to tubing pressure and a second piston face open to annular pressure, such that a pressure differential can be set up between the first piston face and the second piston face to drive the sleeve toward a low pressure side from the first position into the second position with the sleeve continuing to cover the port; and a driver to move the sleeve from the second position into the third position, the driver being unable to move the sleeve until the pressure differential is substantially dissipated.
In accordance with another broad aspect of the present invention there is provided a method for opening a port through the wall of a ported sub, the method comprising: providing a sub with a port through its tubular side wall; providing a hydraulically actuable valve to cover the port, the valve being actuable to move away from a position covering the port to thereby open the port; increasing pressure within the sub to create a pressure differential across the valve to move the valve toward the low pressure side, while the port remains closed by the valve; thereafter, reducing pressure within the sub to reduce the pressure differential; and driving the valve to move it away from a position covering the port.
In accordance with another broad aspect of the present invention there is provided a wellbore tubing string assembly, comprising: a tubing string; and a first plurality of sleeve valves carried along the tubing string, each of the first plurality of sleeve valves capable of holding pressure when a tubing pressure within the tubing string is greater than an annular pressure about the tubing string and the first plurality of sleeve valves being driven to open at substantially the same time as the tubing pressure is substantially equalized with the annular pressure.
In accordance with another broad aspect of the present invention there is provided a method of accessing a hydrocarbon laden formation comprising: providing a plurality of fluid flow regulating mechanisms; constructing a tubing string wherein the plurality of fluid flow regulating mechanisms are grouped into a plurality of areas including a first area including one or more of the plurality of fluid flow regulating mechanisms and a second area including one or more of the plurality of fluid flow regulating mechanisms; placing the tubing string into a wellbore passing into the hydrocarbon laden formation; actuating substantially simultaneously all of the fluid flow regulating mechanisms comprising the first area to access the hydrocarbon laden formation along the first area; and actuating substantially simultaneously all of the fluid flow regulating mechanisms comprising the second area to access the hydrocarbon laden formation along the second area.
In accordance with another broad aspect, there is provided a sleeve valve sub comprising: a tubular segment including a wall defining therein an inner bore; a first port through the wall of the tubular segment; a second port through the wall of the tubular segment; and, a sleeve supported by the tubular segment and installed to be axially moveable relative to the tubular segment from a first position covering the first port to a second position away from a covering position over the first port, the sleeve covering second port in the first position and the second position, the sleeve including an inner facing surface defining a full bore diameter, an inner diameter constriction on the inner diameter of the sleeve having a diameter less than the full bore diameter; an outer facing surface, an indentation on the outer facing surface radially aligned with the inner diameter constriction, the indentation defined by a extension of the outer facing surface protruding inwardly of the full bore diameter, the indentation being positionable over the second port when the sleeve is in the second position such that the second port is openable to fluid flow therethrough by removal of the inner diameter constriction.
It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention.
Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:
The description that follows, and the embodiments described therein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles of various aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention in its various aspects. In the description, similar parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features.
Referring to the Figures, a hydraulically actuable sleeve valve 10 for a downhole tool is shown. Sleeve valve 10 may include a tubular segment 12, a sleeve 14 supported by the tubular segment and a driver, shown generally at reference number 16, to drive the sleeve to move.
Sleeve valve 10 may be intended for use in wellbore tool applications. For example, the sleeve valve may be employed in wellbore treatment applications. Tubular segment 12 may be a wellbore tubular such as of pipe, liner casing, etc. and may be a portion of a tubing string. Tubular segment 12 may include a bore 12a in communication with the inner bore of a tubing string such that pressures may be controlled therein and fluids may be communicated from surface therethrough, such as for wellbore treatment. Tubular segment 12 may be formed in various ways to be incorporated in a tubular string. For example, the tubular segment may be formed integral or connected by various means, such as threading, welding etc., with another portion of the tubular string. For example, ends 12b, 12c of the tubular segment, shown here as blanks, may be formed for engagement in sequence with adjacent tubulars in a string. For example, ends 12b, 12c may be formed as threaded pins or boxes to allow threaded engagement with adjacent tubulars.
Sleeve 14 may be installed to act as a piston in the tubular segment, in other words to be axially moveable relative to the tubular segment at least some movement of which is driven by fluid pressure. Sleeve 14 may be axially moveable through a plurality of positions. For example, as presently illustrated, sleeve 14 may be moveable through a first position (
Sleeve 14 may include a first piston face 18 in communication, for example through ports 19, with the inner bore 12a of the tubular segment such that first piston face 18 is open to tubing pressure. Sleeve 14 may further include a second piston face 20 in communication with the outer surface 12d of the tubular segment. For example, one or more ports 22 may be formed from outer surface 12d of the tubular segment such that second piston face 20 is open to annulus, hydrostatic pressure about the tubular segment. First piston face 18 and second piston face 20 are positioned to act oppositely on the sleeve. Since the first piston face is open to tubing pressure and the second piston face is open to annulus pressure, a pressure differential can be set up between the first piston face and the second piston face to move the sleeve by offsetting or adjusting one or the other of the tubing pressure or annulus pressure. In particular, although hydrostatic pressure may generally be equalized between the tubing inner bore and the annulus, by increasing tubing pressure, as by increasing pressure in bore 12a from surface, pressure acting against first piston face 18 may be greater than the pressure acting against second piston face 20, which may cause sleeve 14 to move toward the low pressure side, which is the side open to face 20, into a selected second position (
One or more releasable setting devices 24 may be provided to releasably hold the sleeve in the first position. Releasable setting devices 24, such as one or more of a shear pin (a plurality of shear pins are shown), a collet, a c-ring, etc. provide that the sleeve may be held in place against inadvertent movement out of any selected position, but may be released to move only when it is desirable to do so. In the illustrated embodiment, releasable setting devices 24 may be installed to maintain the sleeve in its first position but can be released, as shown sheared in
Driver 16 may be provided to move the sleeve into the final position. The driver may be selected to be unable to move the sleeve until releasable setting device 24 is released. Since driver 16 is unable to overcome the holding power of releasable setting devices 24, the driver can only move the sleeve once the releasable setting devices are released. Since driver 16 cannot overcome the holding pressure of releasable setting devices 24 but the differential pressure can overcome the holding force of devices 24, it will be appreciated then that driver 16 may apply a driving force less than the force exerted by the differential pressure such that driver 16 may also be unable to overcome or act against a differential pressure sufficient to overcome devices 24. Driver 16 may take various forms. For example, in one embodiment, driver 16 may include a spring 25 (
In the illustrated embodiment, sleeve 14 moves axially in a first direction when moving from the first position to the second position and reverses to move axially in a direction opposite to the first direction when it moves from the second position to the third position. In the illustrated embodiment, sleeve 14 passes through the first position on its way to the third position. The illustrated sleeve configuration and sequence of movement allows the sleeve to continue to hold pressure in the first position and the second position. When driven by tubing pressure to move from the first position into the second position, the sleeve moves from one overlapping, sealing position over port 28 into a further overlapping, port closed position and not towards opening of the port. As such, as long as tubing pressure is held or increased, the sleeve will remain in a port closed position and the tubing string in which the valve is positioned will be capable of holding pressure. The second position may be considered a closed but activated or passive position, wherein the sleeve has been acted upon, but the valve remains closed. In the presently illustrated embodiment, the pressure differential between faces 18 and 20 caused by pressuring up in bore 12c does not move the sleeve into or even toward a port open position. Pressuring up the tubing string only releases the sleeve for later opening. Only when tubing pressure is dissipated to reduce or remove the pressure differential, can sleeve 14 move into the third, port open position.
While the above-described sleeve movement may provide certain benefits, of course other directions, traveling distances and sequences of movement may be employed depending on the configuration of the sleeve, piston chambers, releasable setting devices, driver, etc. In the illustrated embodiment, the first direction, when moving from the first position to the second position, may be towards surface and the reverse direction may be downhole.
Sleeve 14 may be installed in various ways on or in the tubular segment and may take various forms, while being axially moveable along a length of the tubular segment. For example, as illustrated, sleeve 14 may be installed in an annular opening 27 defined between an inner wall 29a and an outer wall 29b of the tubular segment. In the illustrated embodiment, piston face 18 is positioned at an end of the sleeve in annular opening 27, with pressure communication through ports 19 passing through inner wall 29a. Also in this illustrated embodiment, chamber 26 is defined between sleeve 14 and inner wall 29a. Also shown in this embodiment but again variable as desired, an opposite end of sleeve 14 extends out from annular opening 27 to have a surface in direct communication with inner bore 12a. Sleeve 14 may include one or more stepped portions 31 to adjust its inner diameter and thickness. Stepped portions 31, if desired, may alternately be selected to provide for piston face sizing and force selection. In the illustrated embodiment, for example, stepped portion 31 provides another piston face on the sleeve in communication with inner bore 12a, and therefore tubing pressure, through ports 33. The piston face of portion 31 acts with face 20 to counteract forces generated at piston face 18. In the illustrated embodiment, ports 33 also act to avoid a pressure lock condition at stepped portion 31. The face area provided by stepped portion 31 may be considered when calculating the total piston face area of the sleeve and the overall pressure effect thereon. For example, faces 18, 20 and 31 must all be considered with respect to pressure differentials acting across the sleeve and the effect of applied or inherent pressure conditions, such as applied tubing pressure, hydrostatic pressure acting as driver 16. Faces 18, 20 and 31 may all be considered to obtain a sleeve across which pressure differentials can be readily achieved.
In operation, sleeve 14 may be axially moved relative to tubular segment 12 between the three positions. For example, as shown in
As such, a pressure increase within the tubular segment causes a pressure differential that releases the sleeve and renders the sleeve into a condition such that it can be acted upon by a driving force to move the sleeve to a further position. Pressuring up is only required to release the sleeve and not to move the sleeve into a port open position. In fact, since any pressure differential where the tubing pressure is greater than the annular pressure holds the sleeve in a port-closed, pressure holding position, the sleeve can only be acted upon by the driving force once the tubing pressure generated differential is dissipated. The sleeve may, therefore, be actuated by pressure cycling wherein a pressure increase within the tubular segment causes a pressure differential that releases the sleeve and renders the sleeve in a condition such that it can be acted upon by a driver, such as existing hydrostatic pressure, to move the sleeve to a further position.
The sleeve valve of the present invention may be useful in various applications where it is desired to move a sleeve through a plurality of positions, where it is desired to actuate a sleeve to open after increasing tubing pressure, where it is desired to open a port in a tubing string hydraulically but where the fluid pressure must be held in the tubing string for other purposes prior to opening the ports to equalize pressure and/or where it is desired to open a plurality of sleeve valves in the tubing string hydraulically at substantially the same time without a risk of certain of the valves failing to open due to pressure equalization through certain others of the valves that opened first. In the illustrated embodiment, for example, sleeve 14 in both the first and second positions is positioned to cover port 28 and seal it against fluid flow therethrough. However, in the third position, sleeve 14 has moved away from port and leaves it open, at least to some degree, for fluid flow therethrough. Although a tubing pressure increase releases the sleeve to move into the second position, the valve can still hold pressure in the second position and, in fact, tubing pressure creating a pressure differential across the sleeve actually holds the sleeve in a port closed position. Only when pressure is released after a pressure up condition, can the sleeve move to the port open position. Seals 30 may be provided to assist with the sealing properties of sleeve 14 relative to port 28. Such port 28 may open to an annular string component, such as a packer to be inflated, or may open bore 12a to the annular area about the tubular segment, such as may be required for wellbore treatment or production. In one embodiment, for example, the sleeve may be moved to open port 28 through the tubular segment such that fluids from the annulus, such as produced fluids can pass into bore 12a. Alternately, the port may be intended to allow fluids from bore 12a to pass into the annulus.
In the illustrated embodiment, for example, a plurality of ports 28 pass through the wall of tubular segment 12 for passage of fluids between bore 12a and outer surface 12d and, in particular, the annulus about the string. In the illustrated embodiment ports 28 each include a nozzle insert 35 for jetting fluids radially outwardly therethrough. Nozzle insert 35 may include a convergent type orifice, having a fluid opening that narrows from a wide diameter to a smaller diameter in the direction of the flow, which is outwardly from bore 12a to outer surface 12d. As such, nozzle insert 35 may be useful to generate a fluid jet with a high exit velocity passing through the port in which the insert is positioned. Alternately or in addition, ports 28 may have installed therein a choking device for regulating the rate or volume of flow therethrough, such as may be useful in limited entry systems. Port configurations may be selected and employed, as desired. For example, the ports may operate with or include screening devices. In another embodiment, the ports may communicate with inflow control device (ICD) channels such as those acting to create a pressure drop for incoming production fluids.
As illustrated, valve 10 may include one or more locks, as desired. For example, a lock may be provided to resist sleeve 14 of the valve from moving from the first position directly to the third position and/or a lock may be provided to resist the sleeve from moving from the third position back to the second position. In the illustrated embodiment, for example, an inwardly biased c-ring 32 is installed to act between a shoulder 34 on tubular member 12 and a shoulder 36 on sleeve 14. By acting between the shoulders, they cannot approach each other and, therefore, sleeve 14 cannot move from the first position directly toward the third position, even when shear pins 24 are no longer holding the sleeve. C-ring 32 does not resist movement of the sleeve from the first position to the second position. However, the c-ring may be held by another shoulder 38 on tubular member 12 against movement with the sleeve, such that when sleeve 14 moves from the first position to the second position the sleeve moves past the c-ring. Sleeve 14 includes a gland 40 that is positioned to pass under the c-ring as the sleeve moves and, when this occurs, c-ring 32, being biased inwardly, can drop into the gland. Gland 40 may be sized to accommodate the c-ring no more than flush with the outer diameter of the sleeve such that after dropping into gland 40, c-ring 32 may be carried with the sleeve without catching again on parts beyond the gland. As such, after c-ring 32 drops into the gland, it does not inhibit further movement of the sleeve.
Another lock may be provided, for example, in the illustrated embodiment to resist movement of the sleeve from the third position back to the second position. The lock may also employ a device such as a c-ring 42 with a biasing force to expand from a gland 44 in sleeve 14 to land against a shoulder 46 on tubular member 12, when the sleeve carries the c-ring to a position where it can expand. The gland for c-ring 42 and the shoulder may be positioned such that they align when the sleeve moves substantially into the third position. When c-ring 42 expands, it acts between one side of gland 44 and shoulder 46 to prevent the sleeve from moving from the third position back toward the second position.
The tool may be formed in various ways. As will be appreciated, it is common to form wellbore components in tubular, cylindrical form and oftentimes, of threadedly or weldedly connected subcomponents. For example, tubular segment in the illustrated embodiment is formed of a plurality of parts connected at threaded intervals. The threaded intervals may be selected to hold pressure, to form useful shoulders, etc., as desired.
It may be desirable in some applications to provide the sleeve valve with a port-recloseable function. For example, in some applications it may be useful to open ports 28 to permit fluid flow therethrough and then later close the ports to shut in the well. This reclosure may be useful for wellbore treatment (i.e. soaking), for back flow or production control, etc. As such sleeve 14 may be moveable from the third position to a position overlying and blocking flow through ports. Alternately, in another embodiment with reference to
The valve of
Seals 203, 209 are positioned to create a chamber 212 in communication with the outer surface of the housing through ports. As such, a piston face 210 is formed on the inner tube that can be affected by pressure differentials between the inner diameter of the housing and the annulus.
When the inner tube 213 is installed, it traps the spring 206 between a shoulder 207 on the inner tube and upset shoulder 205 on the housing and radially between itself and the housing. As the inner tube is pushed into place, it compresses the spring 206. The spring is compressed and the inner tube is pushed into the outer tube until a slot in the piston becomes lined up with the shear screw holes in the outer housing. Once this alignment is achieved, shear screws 208 are installed locking the inner tube in position.
As the inner tube of a sleeve valve in generally positioned in an annular groove to avoid restriction of the inner diameter, it is noted that a gap 215 remains between the top of the inner tube and any shoulder 214 forming the upper end of the annular groove. This gap is required to allow movement of the inner tube within the housing. In particular, pressure applied internally will act against piston face 210 and force the inner tube to move upward (away from the end on which piston face 210 is formed). This upward movement will load into the shear pins. Once the force from the internal pressure is increased to a predetermined amount, it will shear the pins 208 allowing the inner tube to move upward until the upper end of the inner tube contacts the shoulder 214 on the housing. When the piston is forced against the housing shoulder, the valve is positioned in the activated and closed position.
The valve will remain in the activated and closed position as long as the internal pressure is sufficient to keep the spring compressed. The pressure differential across face 210 prevents the sleeve from moving down. The tubing pressure can be maintained for an indefinite period of time. Once the pressure differential between the tubing inner diameter and the chamber 212 (which is annular pressure) is dissipated such that the force of spring can overcome the holding force across face 210, the inner tube will be driven down to open the ports.
As the spring expands, it pushes against the shoulders 205 and 207 and moves the inner tube down so that the upper seals 203 move below the port 204 in the outer housing. The valve is then fully open, and fluids from inside the tubing string can be pumped into the annulus, or can be produced from the annulus into the tubing.
The valve can also contain a locking device to keep it in the open position or it can contain the ability to close the piston by forcing it back into the closed position. It may also contain a separate closing sleeve to allow a sleeve to move across the port 204, if required.
While the sleeve is held by tubing pressure against shoulder 214, pressure can be held in the tubing string. At this time tubing or casing pressure operations can be conducted, if desired, such as setting hydraulically actuated packers, such as hydraulically compressible or inflatable packers. Once pressure operations are conducted and completed, the pressure between the tubing and annulus can be adjusted towards equalization, which will allow the driver to open the ports closed by the inner tube.
Several of these valves can be run in a tubing string, and can be moved to the activated but closed and the open positions substantially simultaneously.
The pressures on either side of piston face 210 can be adjusted toward equalization by releasing pressure on the tubing at surface, or by opening a hydraulic opened sleeve or pump-out plug downhole. For example, once a single valve is opened, allowing the pressure to equalize inside and outside of the tubing, all the valves in the tubing string that have been activated will be moved to the open position by the driver, which in this case is spring 206. In one embodiment, for example, a plurality of sleeves as shown in
These tools can be run in series with other similar devices to selectively open several valves at the same time. In addition, several series of these tools can be run, with each series having a different activation pressure.
As shown in
An indexing J keyway may be installed between the sleeve and the tubular segment to hold the sleeve against opening the ports until a selected number of pressure cycles have been applied to the tubing string, after which the keyway releases the sleeve such that the driver can act to drive the sleeve to the third, port open position. An indexing J keyway may be employed to allow some selected sleeves to open while others remain closed and only to be opened after a selected number of further pressure cycles. The selected sleeves may be positioned together in the well or may be spaced apart.
For example, referring to the drawings and particularly to
The illustrated apparatus 120 comprises the plurality of fracing mechanisms 121, 122 each of which includes at least one port 142 through which fluid flow may occur. A plurality of packers 124 are positioned with one or more fracing mechanisms 121, 122 therebetween along at least a portion of the length of the apparatus 120. In some cases, only one fracing mechanism is positioned between adjacent packers, such as in Area I, while in other cases there may be more than one fracing mechanism between each set of adjacent packers, as shown in Area VIII. Although the packers 124 are generically illustrated in
By way of example, the apparatus 120 in the illustration is divided into eight areas designated as Areas I-VIII (Areas III through VII are omitted in the drawings for clarity). In this example, as illustrated, each area comprises four fracing mechanisms 121 or 122 which are designated in
Referring first to
All of the fracing mechanisms in a single area can be opened at the same time. In other words, fracing mechanisms 121 A, B, C and D that reside in Area I (the area nearest the lower end of the well) all open at the same time which occurs after pressurization takes place after ball 126 seats. The fracing mechanisms 122 A, B, C and D, etc. of Areas II, III, etc. remain closed during the opening of fracing mechanisms 121 of Area I and possibly even during any fracing therethrough. Once the Area I mechanisms are open, and if desired the frac is complete, another ball 126a is dropped that lands in a ball receiving mechanism 128a above the top fracing mechanism 121D in Area I. This ball provides two functions; first, it seats and seals off the open fracing mechanisms 121 in Area I; and second, it allows pressure to be applied to the fracing mechanisms 122 that are located above Area I. This next pressurization opens all of the fracing ports in Area II (which is located adjacent to and up-hole from Area I in the string). At the same time, the fracing mechanisms in Area III and higher remain closed. After completing a frac in Area II, another ball is dropped that seats above the fracing mechanisms in Area II and below the fracing mechanisms in Area III, the string is pressured up to open the mechanisms of Area III, and so on.
The fracing mechanisms 121 of Area I may be as described above in
Referring to
Those skilled in the art will understand that the pattern of the slots can be continued by wrapping the slot around the extension of the piston to the extent necessary to open all of the facing ports 142 comprising particular applications of the invention.
Those skilled in the art will also realize and appreciate that although the present invention has been described above and illustrated in the drawings as comprising eight areas other configurations can also be used depending upon the requirements of particular applications of the invention. For example, the number of areas comprising the invention can be equal to, greater than, or less than eight.
In the embodiments of
In one embodiment, for example the sub can include an isolator that isolates tubing pressure from the pressure actuated components of the sleeve until it is desired to open the sleeve to tubing pressure. For example, the tool of
The isolation sleeve includes seals 470a that isolate tubing pressure from the piston face of sleeve 440, when the sleeve is in the position closing access. However, sleeve 470 includes an access port 472 that can be moved into alignment with the tubing pressure fluid access channel to the piston face of sleeve 440 to allow tubing pressure communication to the piston face. If the sleeve overlies fluid treatment/production ports 442, the sleeve, when positioned to permit communication to the fluid access channel (
Isolation sleeve 470 may be moved, by any of various methods and/or mechanisms, along the tubular body from the position closing access to the piston face to the position allowing access to the piston face. For example, sleeve 470 may be moved using actuation by a downhole tool from surface, electrically or remotely by mechanical means unattached to surface. For example, in the illustrated embodiment, sleeve 470 may be moved by landing a ball 474 or other plugging device such as may include a dart, plug, etc., in a sleeve shifting seat 476 (
To better understand the operation of isolation sleeve 470 and sleeve 440, the operation of sleeve is discussed below.
As shown in the illustrated embodiment, for example, the sleeve valve sub may include tubular body 412 with ports 442 extending to provide fluid treatment/production communication between the inner bore 412a of the tubular body and its outer surface 412c. Ports 442 may be closed (
Annulus pressure is communicated to face 420 through unsealed interfaces such as the space 451 between the sleeve and set screws 424 or through other non pressure holding interfaces in sleeve that are open to face 420.
Sleeve 440 can be moved along the tubular body by creating a pressure differential between faces 449 and 420, for example by pressuring up the tubing string to increase the pressure against face 449, while that tubing pressure is sealed from communication to the annulus about the tool and, thereby, to face 420. Set screws 424 in glands 424a or other releasable setting devices retain the sleeve in a selected position on the tubular body, for example, in the run in position (
Driver, herein shown in the form of spring 416 (but alternately may be in the form of an atmospheric chamber, a pressurized chamber, an elastomeric insert, etc.), can be installed to act between the sleeve and tubular body to drive the sleeve once it is initially released to move (by application of a pressure differential). Spring 416 is a compression spring (biased against compression) which acts, when it is free to do so (
Movement of the illustrated sleeve 440 to open ports 442 proceeds as follows, first a pressure differential may be set up across faces 449, 420 with the pressure acting against face 449 exceeding that acting against face 420 (
In view of the foregoing, it can be now more fully appreciated that isolation sleeve 470 may be positioned to close or positioned to allow access of tubing pressure to the fluid channel arising through ports 442, according to the position of access ports 472 on the sleeve. When access ports 472 are in a position preventing fluid access to ports 442, any pressure fluctuations in the tubing string inner diameter through inner bore 412a are isolated from sleeve 440. However, when access ports 472 are at least to some degree open to ports 442, sleeve 440 may be acted upon by fluid pressure to retract the sleeve from ports 442 to open the ports to fluid flow, for formation treatment or production, through ports 472 and 442.
In some embodiments, it may be useful for the ball to continue past its seat after the sleeve has been moved. In such embodiments, yieldable seats or balls may be employed which allow a pressure differential to be set up to move the sleeve, but when the sleeve is stopped against further movement, such as by stopping against shoulder 478, the ball can pass through the seat. For example, the illustrated embodiment includes seat 476 that is yieldable. The ball 474 is capable of passing through the seat after the sleeve has shouldered into a stopped position. Thus, while the ball is seated in
An isolator may be employed to open access to one sleeve at a time. If the isolator is a sleeve for example, the ball may land in the sleeve, move the sleeve and seal off fluid flow past the sleeve. If there is more than one isolator sleeve in a tubing string, the seats 476 of the sleeves may be differently sized such that different sized balls will seal in each of the two or more sleeves. In such an embodiment, the sleeve with the smallest ball is positioned below sleeves with larger seats in order to ensure that the ball capable of seating and sealing therein can pass through the seats above. In particular, where there are a plurality of sleeves with ball seats, each one that is to be actuated independently of the others and is progressively closer to surface, has a seat formed larger than the one below it in order to ensure that the balls can pass through any seats above that ball's intended seat.
In some embodiments, a plurality of isolators may be employed that are actuated by a common function. For example, if it is desired to segment the well, such as for example as shown in
All of the fracing mechanisms in a single area can be opened at the same time. In other words, fracing mechanisms 121 A, B, C and D that reside in Area I (the area nearest the lower end of the well) all can be opened at the same time which occurs after pressurization takes place after ball 126 seats. The fracing mechanisms 122 A, B, C and D, etc. of Areas II, III, etc. remain closed during the opening of fracing mechanisms 121 of Area I and possibly even during any fracing therethrough. Once the Area I mechanisms are open, and if desired the frac is complete, it may be desired to open mechanisms 122 A, B, C and D, etc. of Areas II. To do so, we will assume here that each of the mechanisms include a sleeve-type isolator that isolates the pressure cycling, port opening sleeve from the tubing pressure such as for example shown in
The fracing mechanisms 121 of Area I may be as described above in
The embodiment of
Seals 488 may be positioned on sleeve 470 to provide seals against fluid leakage between the sleeve and body 412 between ports 482 and inner bore 412a.
Even if the sub does not include an isolation sleeve, a sleeve may be employed that is operable, as noted above to open production ports. For example, a production port may be positioned through the tubular body of the tool of
Sleeve 470 may be configured to be recloseable over ports 442 and/or 482. In particular, sleeve 470 may be moveable to overlie one or both of ports 442, 482. For example, in the illustrated embodiment, sleeve may include a profiled neck 496 formed for engagement by a pulling tool, such that the sleeve can be engaged by a tool and pulled up to reclose the ports. The position of the ports through the tubular body and seals on sleeve may be selected to permit closure and fluid sealing. If it is desired to later open the ports again, the isolator sleeve can be moved, as by use of a manipulator tool, back into a port-open position.
If desired, an inflow control device may be positioned to act on fluids passing through one or more of ports 442, 482. In one embodiment, an inflow control device, generally indicated as 482a, such as a screen or a choke, such as an ICD, can be provided to act on fluids passing through the production ports 482 and the sub can be configured such that flow from outer surface 412c to inner bore 412a can only be through production ports and the inflow control device installed therein.
If there are a plurality of sleeves along a length of a tubing string, the chokes may be selected to achieve a production profile. In particular, some chokes may allow greater flow than others to control the rate of production along a plurality of segments in the well.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are know or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”.
This application is a divisional application of U.S. application Ser. No. 12/914,731 filed Oct. 28, 2010 which is presently pending. U.S. application Ser. No. 12/914,731 is a continuation-in-part of PCT application no. PCT/CA2009/000599, filed Apr. 29, 2009, which is a continuation-in-part of U.S. application Ser. No. 12/405,185, filed Mar. 16, 2009. U.S. application Ser. No. 12/914,731 and this application claim priority to US provisional application Ser. No. 61/287,150, filed Dec. 16, 2009 and also claim priority through the above-noted PCT application to US provisional application Ser. No. 61/048,797, filed Apr. 29, 2008.
Number | Date | Country | |
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61048797 | Apr 2008 | US | |
61287150 | Dec 2009 | US |
Number | Date | Country | |
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Parent | 12914731 | Oct 2010 | US |
Child | 14273989 | US |
Number | Date | Country | |
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Parent | PCT/CA2009/000599 | Apr 2009 | US |
Child | 12914731 | US | |
Parent | 12405185 | Mar 2009 | US |
Child | PCT/CA2009/000599 | US |