Patent Number: 
Section: description

In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. As used here, the terms xe2x80x9cupxe2x80x9d and xe2x80x9cdownxe2x80x9d; xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d; xe2x80x9cupwardlyxe2x80x9d and downwardlyxe2x80x9d; xe2x80x9cupstreamxe2x80x9d and xe2x80x9cdownstreamxe2x80x9d; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate. Referring to the drawings in detail, wherein like numerals denote identical elements throughout the several views, one embodiment of the multi-zone sand-control completion 10 of the present invention is shown in FIGS. 1A-1D disposed in a casing 11. The completion 10 may include a first packer 12, a first gravel-pack extension with closing sleeve 14 below the first packer 12, a first upper safety shear sub 15 below the first closing sleeve 14, a first sand screen 16 below the first upper safety shear sub 15, a first surface controlled flow control device 18 below the first sand screen 16, a first lower safety shear sub 19 below the first surface controlled flow control device 18, a second packer 20 below the first lower safety shear sub 19, a second gravel-pack extension with closing sleeve 22 below the second packer 20, a second upper safety shear sub 23 below the second closing sleeve 22, a second sand screen 24 below the second upper safety shear sub 23, a second surface controlled flow control device 26 below the second sand screen 24, a second lower safety shear sub 27 below the second surface controlled flow control device 26, a third packer 28 below the second lower safety shear sub 27, a third gravel-pack extension with closing sleeve 30 below the third packer 28, a third safety shear sub 31 below the third closing sleeve 30, a third sand screen 32 below the third safety shear sub 31, a third surface controlled flow control device 34 below the third sand screen 32, and a fourth, or sump, packer 36 below the third surface controlled flow control device 34. While one embodiment of the invention illustrated in FIGS. 1A-1D includes three sets of sand-control components for treating three production zones (i.e., 42-46), that should not be taken as a limitation. Instead, the present invention may be used with one or more sets of components. Also, although reference is made to closing sleeves 14, 22, 30, other types of fluid communication control devices may be employed in other embodiments. Such closing sleeves 14, 22, 30 or other fluid communication devices can be actuated between open and closed positions. In addition, some closing sleeves and fluid communication devices can also be set at one or more intermediate positions between the open and closed positions. The completion 10 may further include a control conduit 38 running from the earth""s surface (not shown) to the surface controlled flow control devices 18, 26 and 34 and/or to other xe2x80x9cintelligentxe2x80x9d devices. For purposes of this invention the term xe2x80x9cintelligent devicexe2x80x9d includes any device used in xe2x80x9cintelligentxe2x80x9d or xe2x80x9csmartxe2x80x9d well completions, including but not limited to devices such as temperature sensors, pressure sensors, flow-control devices, flow rate measurement devices, oil/water/gas ratio measurement devices, scale detectors, and the like. Although reference is made to a surface controlled intelligent completion device, it is contemplated that, in other embodiments, control may be provided by a downhole control module (instead of a surface control module). Such a downhole control module may be part of an intelligent completion system. In one embodiment, the control conduit 38 may include a plurality of cables, such as one or more electrical, fiber optic or hydraulic cables for transmitting data, signals, pressurized fluid, power, etc. between the earth""s surface and any intelligent device, such as the surface controlled flow control devices 18, 26 and 34. The packers 12, 20, and 28 may be polished bore retrievable packers, and may be of the xe2x80x9cmultiportxe2x80x9d type (i.e., one that allows for passage of a plurality of control lines therethrough), also known as a xe2x80x9ccontrol line bypassxe2x80x9d packer, and be capable of sealably passing the control conduit 38 therethrough while at the same time maintaining pressure integrity. In another embodiment, instead of providing the completion 10 with a control conduit 38, the surface controlled flow control devices 18, 26, and 34 may be controlled from the earth""s surface via pulse technology or other wireless mechanisms, such as by use of electromagnetic signals and the like. As shown at the top of FIG. 1A, a production tubing 40 is attached to the first packer 12, and the entire completion 10 is run into the casing 11 in a single trip. In another embodiment, other components may be coupled between the tubing 40 and the first packer 12. For example, such components may include permanent monitoring devices, gas lift mandrels, safety valves, and so forth. As used here, the production tubing 40 is said to be coupled to the first packer 12 even if there are additional components between the production tubing 40 and the packer 12. The completion 10 is lowered into the casing 11 until the first sand screen 16 is disposed adjacent a first production zone or formation 42 (see FIGS. 1A and 1B), in which position the second sand screen 24 will be disposed adjacent a second production zone or formation 44 (see FIG. 1C) and the third sand screen 32 will be disposed adjacent a third production zone or formation 46 (see FIG. 1D). The casing 11 is provided with perforations 48 through which desirable hydrocarbons, and undesirable sand, may flow from the production zones 42-46 into a well annulus 50. The sand screens 16, 24 and 32 are provided with numerous passageways 52 and internal sleeve members 54, 56 and 58, respectively, the function of which will be explained below. When the completion 10 is being run into the casing 11, the surface controlled flow control devices 18, 26 and 34 and the closing sleeves 14, 22 and 30 are closed to allow fluid circulation to the bottom of the completion 10. Once the completion 10 is properly positioned, the packers 12, 20, 28 and 36 can be set in any manner known in the art (e.g., pressuring up the production tubing 40, via the control line 38, or with a service tool (discussed below and illustrated in FIGS. 2A-2C). Next, each of the production zones 42-46 are gravel packed, beginning with the third, or lower, production zone 46. To begin this process, the third closing sleeve 30 must first be opened (recall from above that all closing sleeves 14, 22 and 30 are closed when the completion 10 is being run into the casing 11, in one embodiment). To enable the closing sleeves 14, 22 and 30 to be remotely opened and closed, in an embodiment, each of them may be provided with a closure member 60, which may include an associated opening mechanism with latching profile 64. Each closure member 60 is adapted to be remotely shifted thereby opening and closing numerous flow ports 62 in the closing sleeves 14, 22 and 30. The completion 10 as shown in FIGS. 1A-1D is in the following configuration: the first closing sleeve 14 has its closure member 60 shifted to its closed position, so as to restrict flow through its flow ports 62 (see FIG. 1A); the second closing sleeve 22 has its closure member 60 shifted to its open position, so as to permit flow through its flow ports 62 (see FIG. 1B); and the third closing sleeve 30 has its closure member 60 shifted to its closed position, so as to restrict flow through its flow ports 62 (see FIG. 1C). The manner in which the closure members 60 are shifted between their opened and closed positions, and the manner in which the distinct production zones 42-46 are independently gravel packed, will now be explained with reference to FIGS. 2A-2C. FIGS. 2A-2C illustrate an enlarged view of the components of the completion 10 shown in FIGS. 1B and 1C that are used to gravel pack the second production zone 44. FIGS. 2A-2C also illustrate a service tool 66. As shown at the top of FIG. 2A, the service tool 66 is attached to a thru-tubing service string 67 (e.g., jointed tubing, coiled tubing, etc.) which are together deployed through the production tubing 40 and into the completion 10. The service tool 66 may be similar in structure and operation to service tools of the type that have been traditionally used in deploying sand-control completions, and may include a standard crossover housing 68 and a ball valve 70, except that the service tool 66 is run through the tubing 40 and is not provided with the structure used in previously existing service tools to attach to and set a packer. While the service tool 66 is shown with a ball valve 70, that should not be taken as a limitation; the present invention is intended to cover service tools 66 that lack a ball valve 70. For example, the service tool 66 may be of the type that is manipulated by movement of the service tool 66 relative to one or more of the packers 12, 20, or 28. The completion 10 may also include: a first inner shoulder 72 between the first packer 12 and the first sand screen 16 (see FIG. 1A); a second inner shoulder 74 between the second packer 20 and the second sand screen 24 (see FIG. 1B); and a third inner shoulder 76 between the third packer 28 and the third sand screen 32 (see top of FIG. 1D). Movement of the ball valve 70 relative to any of the shoulders 72-76 will open and close the ball valve 70. As shown in FIG. 2B, the service tool 66 may be provided with a shifting and latching member 78 for mating with or engaging: each of the closure members 60 on the closing sleeves 14, 22 and 30; and each of the shoulders 72-76. In an embodiment, the shifting and latching member 78 may be a collet. As the service tool 66 is run through the completion 10, the member 78 is used to shift the closure members 60 between their open and closed positions, to thereby selectively permit and restrict fluid flow through the flow ports 62 of the closing sleeves 14, 22 and 30. It is noted that the closing sleeves 14, 22 and 30 may also be shifted between their open and closed positions by any known intervention tool. The member 78 may also function to releasably engage the service tool 66 with the completion 10 by engagement with any of the shoulders 72-76. Before explaining in detail how the service tool 66 is used within the completion 10, one particular manner in which the latching/shifting member 78 may be used to open and close the closure members 60 will first be explained. In an embodiment, as the service tool 66 is lowered through the well completion 10 the latching/shifting member 78 will contact each closure member 60 and step, or increment, the opening mechanism 64 (e.g., a ratchet mechanism) associated with each closure member 60. These initial downpasses will not, however, shift the closure members 60 to their open positions. After the member 78 passes the closure member 60 on the third closing sleeve 30, the service tool 66 is raised up above the third closure member 60 and then lowered back down over the third closure member 60. This second downpass of the member 78 across the third, or lowermost, closure member 60 will shift the lowermost closure member 60 to its open position. Once the lowermost, or third, production zone 46 has been treated (as more fully explained below), the service tool 66 is raised up again. The member 78 will pass across and close the lowermost closure member 60 as it moves upwardly. The service tool 66 will continue upwardly to treat the second production zone 44, and then the first production zone 42, in the same manner as discussed above with regard to the third closing sleeve 30. In another embodiment, the latching/shifting member 78 is lowered in a collapsed state so that as the service tool 66 is run through the completion 10, the latching/shifting member 78 does not engage the closure member 60 of each closing sleeve. Once the latching/shifting member 78 according to this alternative embodiment is lowered below the lowermost closure member 60, the latching/shifting member 78 can be deployed by some activation stimulus, e.g., increased pressure, applied mechanical force, electrical signaling, etc. The service tool 66 is used in connection with the completion 10 to independently gravel pack or circulate fluids through each of the production zones 42-46. For illustration purposes only, the manner in which the service tool 66 operates will be explained in relation to the second production zone 44, and with reference to FIGS. 2A-2C. For purposes of the following discussion, it is assumed that the third, or lower, production zone 46 has already been treated in the manner about to be described. When the second production zone 44 is being treated, the first closing sleeve 14 and the first surface controlled flow control device 18 are closed, as are the third closing sleeve 30 and the third surface controlled flow control device 34. The shifting/latching member 78 on the service tool 66 (FIG. 2B) is used to shift the closure member 60 on the second closing sleeve 22 (FIG. 2A) to its open position, thereby permitting fluid flow through the flow ports 62 in the second closing sleeve 22. The service tool 66 is then moved downwardly so as to bring the shifting/latching member 78 into engaged relationship with the second shoulder 74, as shown at the top of FIG. 2B. Once the service tool 66 has been so positioned, a gravel pack slurry, represented by arrows 80 in FIG. 2A, is pumped downwardly within the service string 67 and is directed through a radial port 82 in the crossover housing 68 and through the open flow ports 62 in the second closing sleeve 22 into the annulus 50 below the second packer 20. It is noted that the service tool 66 may include one or more annular seals 84 to prevent downward fluid flow into the space between the service tool 66 and the completion 10. The fluid continues down the annulus 50 and, as shown in FIGS. 2B and 2C, may be xe2x80x9csqueezedxe2x80x9d into the second formation 44 through the perforations 48, as indicated, for example, by arrow 86. The ball valve 70 or the second surface controlled flow control device 26 are closed during this xe2x80x9csqueezexe2x80x9d operation. It is noted that, since the second surface controlled flow control device 26 can restrict fluid flow by itself, it is not necessary for the service tool 66 to be provided with the ball valve 70 in order to perform a xe2x80x9csqueezingxe2x80x9d operation. It is further noted that the third packer 28 (FIG. 1C) prevents the slurry from migrating downwardly in the casing 11 to the third production zone 46. Next, when it is desired to circulate the slurry to the earth""s surface (not shown), the service tool 66 is stroked relative to the second shoulder 74 to open the ball valve 70, and a signal is sent via the control conduit 38 to open the second surface controlled flow control device 26. Fluid flow is then directed down the service string 67 and into the annulus 50 below the second packer 20 in the same manner as discussed above. But instead of squeezing the fluid into the second formation 44, slurry represented by arrows 88 (FIGS. 2B and 2C) flows through the passageways 52 in the second sand screen 24, into an annular passageway 90 formed between the sand screen 24 and the internal sleeve member 56 (also referred to as being xe2x80x9cinsidexe2x80x9d the sand screen 24) through a flowpath 92 communicating with the annular passageway 90 and flow ports 94 in the second surface controlled flow control device 26, through the open flow ports 94, and into a longitudinal bore 96 of the completion 10. The slurry continues to circulate upwardly into a longitudinal bore 98 of the service tool 66, as represented by arrow 100 in FIG. 2B. The slurry continues past the now-open ball valve 70 and into a longitudinal passageway 102 in the crossover housing 68 of the service tool 66, as represented by arrows 104 in FIG. 2A. With reference to the top of FIG. 2A, slurry flow continues upwardly through the longitudinal passageway 102, out through a discharge port 106 in the crossover housing 68, and upwardly to the earth""s surface through an inner annulus 108 formed between the service string 67 and the completion 10 or the production tubing 40. Upon completion of pumping operations with regard to the second production zone 44, a signal will be sent via the control conduit 38 to the second surface controlled flow control device 26 to close its flow ports 94, and the service tool 66 will be lifted upwardly to treat the first production zone 42. As the service tool 66 is being lifted upwardly, the shifting/latching member 78 (FIG. 2B) will engage and shift the closure member 60 on the second closing sleeve 22 to its closed position so as to restrict fluid flow through the flow ports 62 in the second closing sleeve 22. By closing the second surface controlled flow control device 26 and the second closing sleeve 22, the second production zone 44 is isolated from the first and third production zones 42 and 46. The first production zone 42 is treated in the same manner as described above with regard to the second production zone 44. The service tool 66 will be moved to each subsequent production zone to perform the necessary pumping operations until all zones have been treated. The service tool 66 will then be removed from the casing 11. Production of hydrocarbons may then commence by sending a signal to open one or more of the surface controlled flow control devices 18, 26 or 34. FIGS. 3A-3D illustrate a different embodiment of the completion 10 shown in FIGS. 1A-1D. Similar to the relation between FIGS. 2A-2C and FIGS. 1A-1D, FIGS. 4A-4C illustrate the more detailed view of one set of elements (those adjacent to the second production zone 44) of the completion 10 shown in FIGS. 3A-3D. With respect to all of the figures, like reference numbers correspond to like elements. The main differences between the embodiment illustrated in FIGS. 1A-1D and the embodiment illustrated in FIGS. 3A-3D are that the embodiment of FIGS. 3A-3D includes an additional first sealing element 150, second sealing element 152, and third sealing element 154 as well as a different type of first, second, and third flow control devices 156, 158, and 160. In addition, unlike the embodiment of FIGS. 1A-1D, the embodiment illustrated in FIGS. 3A-3D does not include first, second, or third lower safety shear subs 19, 27, and 31. However, their inclusion in the completion 10 is optional to the user. In the embodiment shown in FIGS. 3A-3D, a first sealing element 150 is disposed intermediate the first sand screen 16 and the first flow control device 156, a second sealing element 152 is disposed intermediate the second sand screen 24 and the second flow control device 158, and a third sealing element 154 is disposed intermediate the third sand screen 32 and the third flow control device 160. First, second, and third sealing elements 150, 152, 154 may comprise packers, such as compression or cup packers, that may be of the xe2x80x9cmultiportxe2x80x9d type (i.e., one that allows for passage of a plurality of control lines therethrough), also known as a xe2x80x9ccontrol line bypassxe2x80x9d packer, and be capable of sealably passing the control conduit 38 therethrough while at the same time maintaining pressure integrity and sealing against casing 11. For those embodiments in which sealing elements 150, 152, and 154 include settable elements (i.e., non-cup packers), first, second, and third sealing elements 150, 152, 154 may be set at the same time as packers 12, 20, 28 and 36 in any manner known in the art (e.g., pressuring up the production tubing 40, via the control line 38, or with a service tool). First sealing element 150 divides the annulus 50 between first packer 12 and second packer 20 into a first upper annular region 170 and a first lower annular region 172. Second sealing element 152 divides the annulus 50 between second packer 20 and third packer 28 into a second upper annular region 174 and a second lower annular region 176. Third sealing element 154 divides the annulus 50 between third packer 28 and fourth packer 36 into a third upper annular region 178 and a third lower annular region 180. A bypass flowpath 182 that provides fluid communication between the annular passageway 90 of each of the first, second, and third sand screens 16, 24, and 32 and its respective lower annular regions 172, 176, and 180, is defined in completion 10. Preferably, a bypass flowpath 182 is defined by each of the first, second, and third sealing elements 150, 152, 154. The first, second, and third lower annular regions 172, 176, and 180 are, in turn, in fluid communication with the flow ports 94 (when open) of the first, second, and third fluid control devices 156, 158, and 160, respectively. FIG. 5 shows a cross-sectional view of the sealing element 150, 152, or 154. A outer layer 202 formed of an elastomer or other compressible material is engageable against the inner wall of the casing 11 to form a seal. The outer layer 202 is carried on a mandrel 206 through which longitudinal channels 214 can be formed for communication with respective channels of the control conduit 38. In addition, bypass conduits 212 are longitudinally formed through the sealing element 150, 152, or 154. The bypass conduits 212 are in communication with the bypass flowpath 182 shown in FIG. 4C. The bypass conduits 212 connect the annular passageway 90 to the bypass flowpath 182. In another embodiment, instead of plural bypass conduits 212, a single bypass conduit 212 may be employed. An inner sleeve 208 of the sealing element 150, 152, 154 defines a longitudinal bore 210 through which fluids may flow. The gravel pack operation of the embodiment of FIGS. 3A-3D/4A-4C is generally the same as the gravel pack operation of the embodiment of FIGS. 1A-1D/2A-2C until it is desired to circulate slurry to the earth""s surface. It is noted, however, that the presence of the first, second, and third sealing elements, 150, 152, 154, (when set) prohibits the passage of gravel pack from each of the upper annular regions, 170, 174, 178, to its respective lower annular region, 172, 176, 180. In the embodiment of FIGS. 3A-3D/4A-4C, when it is desired to circulate the slurry to the earth""s surface (not shown), the service tool 66 is stroked relative to the second shoulder 74 to open the ball valve 70, and a signal is sent via the control conduit 38 to open the second flow control device 158. Fluid flow is then directed down the service string 67 and into the second upper annular region 174 below the second packer 20. But instead of squeezing the fluid into the second formation 44, slurry represented by arrows 88 (FIGS. 4B and 4C) flows through the passageways 52 in the second sand screen 24, into an annular passageway 90 formed between the sand screen 24 and the internal sleeve member 56, through the bypass flowpath 182, into the second lower annular region 176, through the open flow ports 94, and into longitudinal bore 96 of the completion 10. The slurry continues to circulate upwardly into a longitudinal bore 98 of the service tool 66, as represented by arrow 100 in FIG. 4B. The slurry continues past the now-open ball valve 70 and into a longitudinal passageway 102 in the crossover housing 68 of the service tool 66, as represented by arrows 104 in FIG. 4A. With reference to the top of FIG. 4A, slurry flow continues upwardly through the longitudinal passageway 102, out through the discharge port 106 in the crossover housing 68, and upwardly to the earth""s surface through an inner annulus 108 formed between the service string 67 and the completion 10 or the production tubing 40. Upon completion of pumping operations with regard to the second production zone 44, a signal will be sent via the control conduit 38 to the second flow control device 158 to close its flow ports 94, and the service tool 66 will be lifted upwardly to treat the first production zone 42. The remainder of the operation of the embodiment of FIGS. 3A-3D/4A-4C is the same as that of the embodiment of FIGS. 1A-1D/2A-2C. The majority of prior art flow control devices direct flow to and from the annulus and inner bore of a tubing string. The embodiment of completion 10 illustrated in FIGS. 3A-3D/4A-4C enables the use of such prior art flow control devices primarily by including the first, second, and third sealing elements, 150, 152, 154, and the bypass flowpath 182, which provides fluid communication between the annular passageway 90 of each of the first, second, and third sand screens 16, 24, and 32 and the first, second, and third lower annular regions 172, 176, and 180, respectively. On the other hand, in the embodiment of completion 10 illustrated in FIGS. 1A-1D/2A-2C, a flowpath 92 directly communicates the annular passageway 90 of each of the first, second, and third sand screens, 16, 24, 32, with the flow ports of each of the flow control devices, 18, 26, 34, without first passing the flow through any part of the annulus 50. Thus, since the flow does not pass from the annulus to the inner bore in the embodiment of FIGS. 1A-1D/2A-2C, the prior art flow control devices could not be used with the embodiment of completion 10 illustrated in FIGS. 1A-1D/2A-2C, without first changing the design of such flow control devices. To produce hydrocarbons using the device of FIGS. 4A-4C, the service tool 66 is first removed. Since the production tubing 40 is in place, appropriate downhole and surface valves may be actuated and pumps (if any) may be activated to start the production. The hydrocarbons flow from the formation 44 through the perforations, gravel pack, and sand screen into the annular passageway 90. The hydrocarbons flow down the annular passageway through the one or more bypass conduits 212 to corresponding one or more bypass flowpaths 182. The hydrocarbons then flow through the annular region 176 and through the flow control device 158 to the longitudinal bore 96 of the completion 10. In light of the above description, it should now be readily apparent that the present invention positively addresses the need for a multiple-zone sand control completion system, and does so without the spacing drawback suffered by other systems. As noted above, other systems require a minimum spacing distance between adjacent production zones or sand screens, since they rely upon external annular seals of a service tool to isolate production zones from each other. With the present invention, however, the production zones are isolated internally from each other by the flow control devices and closure members. As such, the present invention provides a multiple-zone sand control completion system that avoids the spacing drawback suffered by other systems. In addition, this flexibility in spacing allows for the insertion, if desired, of additional tubing string in between any of the completion components. It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials or embodiments shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art. For example, the various embodiments of the completion 10 of the present invention are shown disposed within a vertical, cased well bore. This should not be taken as a limitation. Instead, the invention is equally application to open hole and/or horizontal well bores. Also, in addition to using the present invention for gravel packing purposes, it may also be used for many other purposes, such as for cleaning, stimulating and fracturing, to name a few. Further, while the present invention has been explained in relation to three production zones, that should not be taken as a limitation. Instead, the present invention may be used to treat any number of formations. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.