WO2018208493A1

WO2018208493A1 - Temporary barrier for inflow control device

Info

Publication number: WO2018208493A1
Application number: PCT/US2018/028946
Authority: WO
Inventors: Nauman Mhaskar
Original assignee: Weatherford Technology Holdings, Llc
Priority date: 2017-05-12
Filing date: 2018-04-23
Publication date: 2018-11-15
Also published as: US20180328139A1; CA3060642A1; AU2018266280A1; SG11201909901RA; NO20191204A1; BR112019023863A2; GB201914734D0; GB2575928A

Abstract

An apparatus (100) for controlling fluid flow in a borehole includes a basepipe (110) and a flow device (130). The basepipe (110) has a through-bore (112) and defines at least one perforation (115). The throughbore (112) conveys the fluid flow, and the at least one perforation (115) communicates the through-bore (112) outside the basepipe (110). The flow device (130) comprises a barrier (150) disposed at the at least one perforation (115). The barrier (150) at least temporarily prevents fluid communication through the at least one perforation (115). The barrier (150) is resistant to a pressure differential thereacross and is dissolvable over time. The barrier (150) can include at least two elements (170, 172, 174) composed of different materials, and an increase in the pressure differential across can further increase how the barrier (150) prevents the fluid communication through the perforation (115).

Description

Temporary Barrier for Inflow Control Device

-by-

Nauman H. Mhaskar

BACKGROUND OF THE DISCLOSURE

[0001] Reservoir completion systems installed in production, injection, and storage wells often incorporate screens positioned across the reservoir sections to prevent sand and other solids particles over a certain size from entering the reservoir completion.

Conventional sand screen joints are typically assembled by wrapping a filter media around a perforated basepipe so fluids entering the sand screen from the wellbore must first pass through the filter media. Solid particles over a certain size will not pass through the filter media and will be prevented from entering the reservoir completion.

[0002] For example, a reservoir completion system 10 in Fig. 1 has completion screen joints 20 deployed on a completion string 14 in a borehole 12. Typically, these screen joints 20 are used for boreholes passing in an unconsolidated formation, and packers 16 or other isolation elements can be used between the various joints 20 to isolate various zones 30A-30C of the formation. During production, fluid produced from the borehole 12 directs through the screen joints 20 and up the completion string 14 to the surface rig 18. The screen joints 20 keep out fines and other particulates in the produced fluid. In this way, the screen joints 20 can prevent the production of reservoir solids, can in turn mitigate erosion damage to both well and surface components, and can prevent other problems associated with fines and particulate present in the produced fluid.

[0003] In addition to use in an open hole, the screen joints 20 can also be used in cased holes. Additionally, the screen joints 20 can be used for gravel pack operations in which gravel [e.g., sand) is disposed in the annulus of the borehole around the screen joint 20 to support the unconsolidated formation of the open borehole 12.

[0004] Installing the screen joints 20 in the borehole 12 can offer some challenges because fluid can pass through the screen joints 20 during run-in. Additionally, it may be desirable to delay fluid communication through the screen joints 20 at least for a period of time during and after installation. To that end, the subject matter of the present disclosure is directed to solving one or more of these challenges along with other possible problems. SUMMARY OF THE PRESENT DISCLOSURE

[0005] An apparatus according to the present disclosure controls fluid flow in a borehole. The apparatus comprises a basepipe and a flow device. The basepipe has a through-bore conveying the fluid flow and defines at least one perforation communicating the through- bore outside the basepipe. The flow device comprises a barrier disposed at the at least one perforation. The barrier at least temporarily prevents fluid communication through the at least one perforation. The barrier is resistant to a pressure differential thereacross and is dissolvable over time.

[0006] In one arrangement, the barrier comprises at least two elements composed of different materials. In addition or in an alternative arrangement, the barrier increases the at least temporary prevention of the fluid communication in response to an increase in the pressure differential thereacross.

[0007] The flow device can include at least one nozzle disposed relative to the at least one perforation. The at least one nozzle creates a pressure drop in fluid communication therethrough.

[0008] The flow device can include a fixture affixed at the at least one perforation and defining an orifice therethrough. The fixture holds the barrier captive in the at least one perforation. The orifice of the fixture can include a nozzle disposed thereon for creating a pressure drop in fluid communication therethrough. In general, the nozzle can be composed of a tungsten carbide material. For its part, the fixture can thread into a threaded counterbore of the at least one perforation, although other techniques can be used to affix the fixture.

[0009] In one arrangement, the barrier having the at least two elements of different materials comprise a plurality of barrier layers held captive in the at least one perforation with the fixture. The barrier layers at least temporarily prevent fluid communication between the at least one perforation of the basepipe and the orifice of the fixture.

[0010] The barrier layers can include an inner layer of a first dissolvable material encapsulating in an outer layers of a second dissolvable material different from the first dissolvable material. In an alternative, the barrier layers can include an intermediate layer of a first dissolvable material disposed between first and second layers of a second dissolvable material different from the first dissolvable material.

[0011] In another arrangement, the barrier of the flow device can comprises at least two elements composed of different materials. For example, a first of the at least two elements can include a plug composed of a dissolvable metal as one of the different materials. The plug can be affixed (threaded, welded, etc.) at the at least one perforation. A second of the at least two elements can include a washer composed of a dissolvable material as another of the different materials. The washer can be held captive in between the plug and the perforation. In another example, a first of the at least two elements can include a plug composed of a dissolvable metal as one of the different materials, and the plug can be affixed at the at least one perforation. Here, a second of the at least two elements can include a coating composed of a dissolvable material as another of the different materials and coating the plug.

[0012] In general, the fixture can be composed of a steel material. The first dissolvable material can be composed of a dissolvable metallic material, and the second dissolvable material can be composed of a dissolvable gasket material. Using such different metallic and gasket materials for the layers can allow the at least two elements of the barrier to increase the at least temporary prevention of the fluid communication in response to an increase in the pressure differential thereacross.

[0013] The apparatus can include a filter disposed on the basepipe adjacent the flow device. The filter filters the fluid flow from the borehole to the at least one perforation. For example, the filter and the basepipe can define a gap therebetween communicating the fluid flow with the flow device. A housing of the flow device in fluid communication with the gap can communicating the gap with the at least one perforation. The housing can include at least one nozzle creating a pressure drop in the fluid flow from the gap to the at least one perforation. The flow device can event include at least one inflow valve permitting communication of the fluid flow in an inflow direction from the gap to the at least one perforation and preventing communication of the fluid flow in an outflow direction from the at least one perforation to the gap.

[0014] In another arrangement, the barrier can include a sleeve disposed inside the throughbore of the basepipe adjacent the at least one perforation. At least one seal can seal between the sleeve and the throughbore on both sides of the at least one perforation. In this arrangement, the sleeve can be composed of a dissolvable metallic material, while the at least one seal can be composed of a dissolvable gasket material. A nozzle can be affixed at least partially in the at least one perforation. The at least one seal can also be a plurality of ridges defined on an exterior of the sleeve that engage an inside surface of the throughbore. [0015] As one example, the apparatus can be a joint for a completion string having the basepipe with the throughbore for conveying the production fluid to the surface. To prevent sand and other fines from passing through openings in the basepipe to the throughbore, a filter or screen can be disposed on the basepipe for screening fluid produced from the surrounding borehole, although a filter or screen may not be always used. Disposed on the basepipe, the flow device having the housing defines a housing chamber in fluid communication with screened fluid from the screen. During production, fluid passes through the screen, enters the housing chamber, and eventually passes into the basepipe's bore through the pipe's perforations.

[0016] To prevent the flow of the fluid at least temporarily through the screen joint during run-in and for a time thereafter, the flow device disposed on the joint includes barriers as discussed herein disposed at the perforations of the basepipe.

[0017] To control the flow of the fluid and create a desired pressure drop for even-flow along the screen joint, the flow device disposed on the joint controls fluid communication from the housing's chamber to the openings in the basepipe. In one implementation, the flow device includes one or more nozzles.

[0018] According to the present disclosure, a method is used for controlling fluid flow from a borehole. A basepipe is run into the borehole. The basepipe has a throughbore for conveying the fluid flow and defines at least one perforation for communicating the throughbore outside the basepipe. At least one barrier disposed at the at least one perforation at least temporarily prevents fluid communication through the at least one perforation. The at least one barrier is resistant to pressure and is dissolvable over time. Eventually, after dissolution of the at least one barrier, fluid communication is allowed through at least one nozzle disposed at the at least one perforation.

[0019] The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Fig. 1 illustrates a completion system having screen joints according to the prior art deployed in a borehole.

[0021] Fig. 2A illustrates, in partial cross-section, a screen assembly having a screen disposed on a basepipe in conjunction with an inflow control device having a temporary barrier according to the present disclosure. [0022] Fig. 2B illustrates, in detailed cross-section, a screen assembly having another inflow control device with a temporary barrier according to the present disclosure.

[0023] Fig. 2C illustrates, in detailed cross-section, a screen assembly having yet another inflow control device with a temporary barrier according to the present disclosure.

[0024] Fig. 2D illustrates, in cross-section, a basepipe having injection ports with temporary barriers of the present disclosure.

[0025] Figs. 3A-3B illustrate a cross-sectional views of a first temporary barrier of the present disclosure.

[0026] Fig. 4A illustrates a cross-sectional view of a second temporary barrier of the present disclosure.

[0027] Fig. 4B illustrates a cross-sectional view of a third temporary barrier of the present disclosure.

[0028] Fig. 4C illustrates a cross-sectional view of a fourth temporary barrier of the present disclosure.

[0029] Figs. 4D-4E illustrate cross-sectional views of alternative elements for the temporary barriers of the present disclosure.

[0030] Figs. 5A-5B illustrate cross-sectional views of a fifth temporary barriers of the present disclosure.

[0031] Fig. 5C illustrate a cross-sectional views of a sixth temporary barriers of the present disclosure.

[0032] Figs. 6A-6C illustrate cross-sectional views of seventh, eighth and ninth temporary barriers of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0033] As shown in Fig. 2A, an apparatus 100 for controlling fluid flow in a borehole includes a basepipe 110 and a flow device 130. The basepipe 110 has a throughbore 112 and defines at least one perforation 115. The throughbore 112 conveys the fluid flow, and the at least one perforation 115 communicates the throughbore 112 outside the basepipe 110.

[0034] The apparatus 100 can be a screen assembly, as illustrated in partial cross-section in Fig. 2A, and can have a screen 120 disposed on the basepipe 110. As is typical, the screen 120 includes wire 122 wrapped about rods or ribs 124 disposed longitudinally along the length of the basepipe 110. The wire 122 is typically V-wire that filters fluid flow from the borehole to an annular space or drainage layer 125 between the wire 122 and the outside of the basepipe 110. The wire 122 forms various slots for screening produced fluid, and the longitudinal ribs 124 create channels that operate as a drainage layer 125. Other types of screen assemblies can be used for the screen 120, including metal mesh screens, pre-packed screens, protective shell screens, or screens of other construction. Moreover, any other form filter can be used for the screen 120, including one or more layers of wire wrappings, porous metal fiber, sintered laminate, pre-packed media, etc.

[0035] An end ring 126 on one end of the basepipe 110 closes off the drainage layer 125 so the filtered fluid entering the drainage layer 125 through the screen 120 is directed to the flow device 130 disposed on the other end of the screen 120. In this context, the flow device 130 is an inflow control device for the screen 120. The flow device 130 includes a housing 132 abutting the screen 120 and defining an interior annulus 135 communicating with the screen's drainage layer 125. The housing 132 is a cylindrical sleeve that slides on the basepipe 110 over a fixed end ring 134 attached to the basepipe 110. A threaded end ring 136 threads onto the fixed end ring 134 to keep the housing 132 abutted to the screen 120.

[0036] As noted, the basepipe 110 defines the throughbore 112 for the passage of fluids, such as production fluids produced from the formation. The perforations 115 in the basepipe 110 communicate this throughbore 112 with the interior 135 of the flow device 130 so that fluid filtered through the screen 120 and entering the interior 135 can pass into the basepipe 110 to be carried to the surface.

[0037] In general, the apparatus 100 can be used for "gravel pack" or "fracture pack" operations or can be an openhole screen joint. During production, reservoir fluids travel through the screen 120 and into the drainage layer 125 between the screen 120 and the basepipe 110. The produced fluid passes along the drainage layer 125 to the flow device 130. Entering the housing 132, the flow would eventually pass through the perforations 115 and in the basepipe 110.

[0038] Before production commences, however, various operations may need to be performed in which fluid flow is preferably prevented from passing between the screen 120 and the basepipe 110 through the perforations 115. For this reason, each of the perforations 115 (or at least some of them) include a barrier insert 150 disposed therein. The barrier insert 150 is resistant to pressure and is dissolvable over time so fluid passage can be at least temporarily prevented. [0039] During run-in, for example, the screen assembly 100 along with other completion equipment can be installed in a borehole without using an inner string because the barrier inserts 150 can keep flow of running fluid through the basepipe 110 without escaping through the perforations 115 and screen 120. Additionally, once the completion is positioned, well fluids can be displaced from the completion through the shoe while the screen assembly 100 provides isolation. In some implementations, it may be desirable to prevent the flow through the perforations 115 for several days after installation of the screen assembly 100 so various operations can be performed before the screen assembly 100 is actually intended to be ready for use.

[0040] Fig. 2B illustrates the flow device 130 of the screen assembly 100 showing the barrier insert 150 in more detail. The barrier insert 150 disposed at the perforation 115 includes a nozzle 160 and barrier 165. The nozzle 160 allows fluid communication therethrough and is designed to produce a pressure drop in the flow, such as according to the purposes of an inflow control device. Although the nozzle 160 allows fluid

communication therethrough, the barrier 165 at least temporarily prevents fluid communication through the perforation 115.

[0041] The barrier 165 removes [e.g., dissolves, degrades, disintegrates, erodes, or the like) over time to open up flow through the nozzle 160. (According to the present disclosure, the barrier 165 is described as "dissolving" or being "dissolvable." It will be appreciated with the benefit of the present disclosure that other forms of removal can also be applicable, including degrading, disintegrating, eroding, or the like.) Once the barrier 165 removes, the flow device 130 with the nozzle 160 operates as an inflow control device to control flow of fluid into the screen assembly 100— particularly to control the flow of production fluid during production operations. As noted, the nozzle 160 can produce a pressure drop in the fluid, and the size and/or number of the nozzles 160 can be configured for a given implementation.

[0042] The flow device 130 may or may not have a check valve with ball 138 and seat 137 as shown captured in the housing 132 of Fig. 2B. The ball 138 permits communication of the fluid flow in an inflow direction from the drainage layer 125 to the perforation 115 and prevents communication of the fluid flow in an outflow direction from the perforation 115 to the drainage layer 125.

[0043] As shown, the barrier insert 150 with the nozzle 160 and temporary barrier 165 can be used to cover the perforations 115 for an inflow control device 130. However, the insert 150 (with or without the nozzle 160) could be used for other borehole devices, such as a limited entry liner (LEL), injection tubular, downhole tool, or other such device having a port or perforation suitable for temporary covering.

[0044] Fig. 2C illustrates an alternative arrangement in which the flow device 130 includes the nozzle 160 disposed in the housing 132 apart from the barrier insert 150 at the perforation 115 having the barrier 165. In this case, the barrier insert 150 does not necessarily include an integrated nozzle. As Figs. 2A-2C show, various arrangements can be used for a flow device 130 having a nozzle 160 and barrier 165.

[0045] Fig. 2D illustrates, in cross-section, a basepipe 110 having perforations 115 with temporary barrier inserts 150 disposed therein. In this configuration in contrast to the previous arrangements, the basepipe 110 may lack a screen assembly, although a screen could be disposed about the basepipe and perforations. Here, the barrier inserts 150 can be used to temporary block the perforations 115 during injection operations, production operations, or both. These barrier inserts 150 have the barriers 165 and may or may not have nozzles 160 as shown.

[0046] The temporary barrier 165 permits the screen assembly 100 (as in Figs. 2A-2C) or the plain basepipe 110 (as in Fig. 2D) to be installed in a borehole without the use of an inner string and isolates the completion string so well fluid can be displaced through the shoe of the completion. The temporary barrier 165 holds pressure for a range of time from hours, to days or weeks based on the particular application and well requirements.

Eventually, the temporary barrier 165 removes [e.g., dissolves, disintegrates, erodes, or the like) so the inflow control device 130 can be used for production. To do this and as discussed in more detail below, the temporary barrier 165 uses a combination of at least two different materials, including dissolvable metal, coatings, and dissolvable gasket rather than a single component, such as a rupture disk, to achieve the required delay.

[0047] With an understanding of how the barrier inserts 150 having the barriers 165 and the optional, integrated nozzles 160 can be used, discussion turns to a particular configuration illustrated in detail in Figs. 3A-3B. In this configuration, the barrier insert 150 disposed at the perforation 115 incorporates both the nozzle 160 and the barrier 165. A fixture or cap 152 is affixed at the perforation 115 and defines an orifice 154

therethrough. The fixture 152 holds the barrier 165 captive in the perforation 115, and the orifice 154 of the fixture 152 includes the nozzle 160 disposed therein. [0048] The fixture 152 can affix in any number of ways in the perforation 115. In the present example, the fixture 152 threads into a threaded counterbore 117 of the perforation 115, but other techniques can be used that involve an interference fit, snap ring, tack weld, etc.

[0049] In general, the barrier 165 includes at least two barrier elements or layers composed of different materials. In the present example, the barrier 165 includes several barrier layers 170, 172 and 174 held captive in the perforation 115 with the fixture 152. The barrier layers 170, 172 and 174 at least temporarily prevent fluid communication between the perforation 115 of the basepipe 110 and the orifice 154 of the fixture 152. To help hold the sandwiched layers 170, 172, and 174, the fixture 152 can include a surrounding lip forming a pocket 156 in the fixture 152. Meanwhile, profiles 158 on the fixture's external surface can facilitate threading the fixture 152 into the perforation 115.

[0050] The fixture 152 can be composed of a steel material, and the nozzle 160 can be composed of erosion-resistant material, tungsten carbide, ceramic, or other comparable material. In one arrangement, the barrier layers 170, 172, and 174 comprise an

intermediate layer 172 of a dissolvable metal inset disposed between first and second layers 170 and 174 of dissolvable rubber gaskets. The metal fixture 152 traps the dissolvable metal inset 172 between the dissolvable rubber gaskets 170, 174 to

temporarily plug the basepipe's perforation 115. Alternatively, a reverse arrangement can be used in which an intermediate dissolvable rubber gasket 172 can be sandwiched between two dissolvable metal insets 170, 174 to temporarily plug the basepipe's perforation 115.

[0051] Either way, the use of the metal inset(s) and rubber gasket(s) for the layers 170, 172, and 174 helps achieve an effective seal. The metal for the inset(s) can be tailored to remove [i.e., dissolve) within a specific time period as can the material of the gasket(s). Additional control over the duration of the temporary barrier 165 can be achieved by coating the dissolvable metal inset(s) with a time delay coating. Thus, a combination of dissolvable metal inset(s) (with or without coating) and the dissolvable rubber gasket(s) can be tailored to achieve a length of time in which the temporary barrier 165 remains in the basepipe 110 before dissolving away to leave the nozzle 160 open to flow.

[0052] According to the present disclosure, suitable material for the inset(s) includes, but is not limited to, dissolvable metallic material; reactive metal; magnesium; aluminum; powder metal; magnesium alloy; calcium, magnesium, and/or aluminum including alloying elements of calcium, magnesium, aluminum, lithium, gallium, indium, zinc, and bismuth; and the like. In addition to exposure to the wellbore environment, dissolution/degradation of the inset(s) can be activated by wellbore fluid, active fluid, brine, acid, and the like.

[0053] According to the present disclosure, suitable material for the gasket(s) includes, but is not limited to, elastomeric material, dissolvable/degradable rubber, degradable composite polymer, polyglycolic acid (PGA) combined with urethane, polylactic acid (PLA) combined with urethane, mixed polymers, composite of rubber beads in PGA, and the like. In addition to exposure to the wellbore environment, dissolution/degradation of the gasket(s) can be activated by wellbore fluid, active fluid, brine, acid, and the like.

[0054] As noted previously, the temporary barrier 165 eventually removes [e.g.,

dissolves, disintegrates, erodes, or the like) so flow can pass through the perforation 115, such as production from outside the basepipe 110 into the throughbore 112. To do this in the present example, the temporary barrier 165 uses a combination of at least two different materials, including the dissolvable metal inset 172 sandwiched between the dissolvable gaskets 170 and 174, rather than a single component, such as a rupture disk, to achieve the required delay.

[0055] Moreover, rather than simply providing a covering of the perforation 115 that can be breached at a predetermined pressure, such as with a rupture disk, the temporary barrier 165 of the present disclosure is resistant to a pressure differential thereacross and more particularly increases the at least temporary prevention of the fluid communication through the perforation 115 in response to an increase in the pressure differential thereacross.

[0056] The barrier 165 can achieve the pressure resistance due to the strength, thickness, material selection, shape, and/or other aspect of at least the metal inset(s). As shown in the present example, the metal inset of the intermediate layer 172 is a flat coin of the dissolvable metal material. Other shapes are possible.

[0057] The barrier 165 can achieve the increased sealing due to the elements or layers 170, 172, 174 of the barrier 165 being sandwiched against one another and being pressed against the surrounding shoulders of the fixture 152 and counterbore 117 of the

perforation 115. In other words, increased sealing can be achieved due to pressure across the barrier 165 tending to further sandwich the elements or layers 170, 172, 174 of the barrier 165 together and tending to further press the elements or layers 170, 172, 174 against the surrounding shoulders (of fixture 152 and counterbore 117) housing the barrier 165.

[0058] A number of variations of the barrier insert 150 can be used. For example, Fig. 4A shows a cross-sectional view of the barrier insert 150 lacking a nozzle 160 integrated into the cap 152. Instead and as noted previously, a separate nozzle (not shown) if desired can be installed elsewhere. Additionally, the inside surface of the orifice 154 for the cap 152 may have a coating, or the cap 152 may be composed of a suitable erosion-resistant material to act as a nozzle for the purposes of controlling flow.

[0059] In previous examples, the barrier insert 150 installed externally on the basepipe 110 into a counterbore 117 of the perforation 115. A reverse configuration is also possible, as shown in Fig. 4B. Here, the counterbore 117 of the perforation 115 can be formed inside the bore 112 of the basepipe 110, and the barrier insert 150 can install internally. Such a reverse form of assembly may be needed when elements external to the basepipe 110 would obstruct the ability to install the barrier insert 150 externally. Moreover, such a reverse form of assembly may be needed when elements external to the perforation 115 on the basepipe 110 need to be heat treated, welded, etc. during the assembly process and would damage the barrier insert 150 if already installed. Whether internal or external, both sides of the barrier 165 are exposed to fluid and other conditions prompting its removal.

[0060] In previous examples, the barrier insert 150 included three elements or layers 170, 172, and 174. More or less elements or layers could be used as the case may be. For example, Fig. 4C illustrates the barrier insert 150 having two elements or layers 170, 172 for the barrier 165. These two layers 170, 172 are preferably composed of different materials and can include a rubber gasket 170 and a metal inset 172, as shown here. The layers 170, 172 can be in either order. The inner pocket 156 of the fixture 152 can be coated with a dissolvable gasket material for the purposes of sealing and acting as an outer layer. The shoulder of the perforation could also or alternatively be coated with a dissolvable gasket material in like manner.

[0061] Fig. 4D illustrates an example of another barrier 165 for use in the barrier insert (150) having a metal inset 173 encapsulated in a gasket shroud 171. This combined element 173/171 can be used alone or in combination with other elements or layers in the barrier insert (150) of the present disclosure. Fig. 4E illustrates another example of a barrier 165 for use in the barrier insert (150) having a metal inset 173 encapsulated in a coating 175. This too can be used alone or in combination with other elements or layers in the barrier insert (150) of the present disclosure. According to the present disclosure, suitable material for the coating 175 can include, but is not limited to, epoxy; thermal barrier of alumina, silica, ceramic, zirconia, rare-earth oxides, metal-glass composites, etc.; anodized layer; and the like.

[0062] Figs. 5A-5B shows cross-sectional views of a barrier insert 150 lacking a nozzle. The insert 150 includes a dissolvable metal plug 180 affixed [e.g., threaded) in the counterbore 117 of the perforation 115 and includes a degradable washer 182 to prevent fluid from breaching the threads and acting as a time delay. The threaded plug 180 can also be coated. A profile 188 allows a tool to thread the plug 180 into the counterbore 117 of the perforation 115.

[0063] In a barrier insert 150 of Fig. 5C, a dissolvable metal plug 180 is affixed [e.g., threaded and welded or inserted and welded) in the counterbore 117 of the perforation 115 to create a seal. A degradable washer is not used, but the threaded plug 180 can be coated.

[0064] Turning to yet another configuration illustrated in detail in Fig. 6A, the barrier insert 150 includes the nozzle 160 affixed at least partially in the perforation 115 and includes the at least one barrier 165 disposed in the throughbore 112 of the basepipe 110. The barrier 165 is a sleeve 190 disposed inside the throughbore 112 of the basepipe 110 adjacent the perforation 115. At least one seal 192 seals between the sleeve 190 and the throughbore 112 on both sides of the perforation 115.

[0065] The sleeve 190 is composed of a dissolvable metal, and the at least one seal 192 includes seal rings composed of a dissolvable rubber. The dissolvable metal sleeve 190 is assembled with the dissolvable rubber seal rings 192. The sleeve 190, which can be swaged to the interior of the basepipe's throughbore 112, is inserted into the throughbore 112. In this way, as the dissolvable metal sleeve 190 expands out, the rubber seals 192 get compressed between the two mating parts and seal the nozzle 160 temporarily.

[0066] In use, the sleeve 190 is not subject a pressure differential from end-to-end and would tend not to move in the bore 112. All the same, a ledge or shoulder 113 can be provided for fixing the sleeve 190. In use, the dissolvable metal of the sleeve 190 reacts with completion fluid and dissolves away. A coating can also be applied to the inside bore of the dissolvable metal sleeve 190 to increase the duration of the temporary barrier. The dissolvable gasket material of the seals 192 also dissolves overtime. [0067] As shown in Fig. 6B, the at least one seal for the dissolvable metal sleeve 190 can alternately include a sheet 194 of dissolvable rubber formed on the outer diameter. This will form a uniform seal along the length of the sleeve 190 rather than just at both ends as described earlier. Although not depicted, it will be appreciated that a reverse arrangement can be used in which the sleeve 190 and seals 192, 194 are disposed externally on the basepipe 110.

[0068] Fig. 6C illustrates another barrier insert 150 including a nozzle 160 affixed at least partially in the perforation 115 and includes the at least one barrier 165 disposed in the throughbore 112 of the basepipe 110. The barrier 165 is a sleeve 190 disposed inside the throughbore 112 of the basepipe 110 adjacent the perforation 115. Instead of or in addition to a rubber seal, the sleeve 190 includes machined ridges 193 on its outer surface that collapse after the sleeve 190 has been swaged out to the basepipe's through-bore 112. These ridges 193 on the outer surface of the sleeve 190 act as a seal against the inside surface of the through-bore 112. As an alternative to enhance the sealing, the sleeve 190 can also be coated with a thin elastomeric coating (degradable or non-degradable) on the machined ridges 193.

[0069] The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. It will be appreciated with the benefit of the present disclosure that features described above in accordance with any embodiment or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other embodiment or aspect of the disclosed subject matter.

[0070] In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for controlling fluid flow in a borehole, the apparatus comprising: a basepipe having a throughbore and defining at least one perforation, the

throughbore conveying the fluid flow, the at least one perforation communicating the throughbore outside the basepipe; and

a flow device comprising a barrier disposed at the at least one perforation, the

barrier at least temporarily preventing fluid communication through the at least one perforation and being dissolvable over time, the barrier being resistant to a pressure differential thereacross and increasing the at least temporary prevention of the fluid communication through the at least one perforation in response to an increase in the pressure differential

thereacross.

2. The apparatus of claim 1, wherein the flow device comprises at least one nozzle disposed relative to the at least one perforation, the at least one nozzle creating a pressure drop in fluid communication therethrough.

3. The apparatus of claim 1, wherein the flow device comprises a fixture affixed at the at least one perforation and defining an orifice therethrough, the fixture holding the barrier captive in the at least one perforation.

4. The apparatus of claim 3, wherein the orifice of the fixture comprises a nozzle disposed thereon, the nozzle creating a pressure drop in fluid communication

therethrough.

5. The apparatus of claim 4, wherein the nozzle comprises an erosion-resistant material.

6. The apparatus of claim 3, 4 or 5, wherein the fixture threads into a threaded counterbore of the at least one perforation.

7. The apparatus of any one of claims 3 to 6, wherein the barrier comprises at least two elements composed of different materials, the at least two elements held captive in the at least one perforation with the fixture, the at least two elements at least temporarily preventing fluid communication between the at least one perforation of the basepipe and the orifice of the fixture.

8. The apparatus of claim 7, wherein the at least two elements comprise an inner layer of a first dissolvable material encapsulated in an outer layer of a second dissolvable material different from the first dissolvable material.

9. The apparatus of claim 7, wherein the at least two elements comprise an

intermediate layer of a first dissolvable material sandwiched between first and second outer layers of a second dissolvable material different from the first dissolvable material.

10. The apparatus of claim 9, wherein the fixture comprises a steel material.

11. The apparatus of claim 9 or 10, wherein the first dissolvable material comprises a dissolvable metallic material, and wherein the second dissolvable material comprises a dissolvable gasket material.

12. The apparatus of any one of claims 1 to 11, wherein the barrier comprises at least two elements of different material increasing the at least temporary prevention of the fluid communication through the at least one perforation in response to an increase in the pressure differential thereacross.

13. The apparatus of claim 12, wherein a first of the different materials of the at least two elements comprises a dissolvable metallic material, and wherein a second of the different materials of the at least two elements comprise a dissolvable gasket material.

14. The apparatus of any one of claims 1 to 13, further comprising a filter disposed on the basepipe adjacent the flow device and filtering the fluid flow from the borehole to the at least one perforation.

15. The apparatus of claim 14, wherein the filter and the basepipe define a gap therebetween communicating the fluid flow with the flow device.

16. The apparatus of claim 15, wherein the flow device comprises a housing in fluid communication with the gap and communicating the gap with the at least one perforation.

17. The apparatus of claim 16, wherein the housing comprises at least one nozzle creating a pressure drop in the fluid flow from the gap to the at least one perforation.

18. The apparatus of claim 16 or 17, wherein the flow device comprises at least one inflow valve permitting communication of the fluid flow in an inflow direction from the gap to the at least one perforation and preventing communication of the fluid flow in an outflow direction from the at least one perforation to the gap.

19. The apparatus of claim 1, wherein the at least one barrier comprises:

a sleeve disposed on the basepipe adjacent the at least one perforation; and at least one seal sealing between the sleeve and the basepipe on both sides of the at least one perforation.

20. The apparatus of claim 19, wherein the sleeve comprises a dissolvable metallic material; and wherein the at least one seal comprises a dissolvable gasket material.

21. The apparatus of claim 19 or 20, wherein the at least one seal comprises a plurality of ridges defined on an exterior of the sleeve and engaging an inside surface of the through- bore.

22. The apparatus of claim 19, wherein a nozzle is affixed at least partially in the at least one perforation.

23. An apparatus for controlling fluid flow in a borehole, the apparatus comprising: a basepipe having a through-bore and defining at least one perforation, the

barrier at least temporarily preventing fluid communication through the at least one perforation and comprising at least two elements composed of different materials, the barrier being resistant to a pressure differential thereacross and being dissolvable over time.

24. The apparatus of claim 23, wherein a first of the at least two elements comprises a plug composed of a dissolvable metal as one of the different materials, the plug affixed at the at least one perforation; and wherein a second of the at least two elements comprises a washer composed of a dissolvable material as another of the different materials, the washer held captive in between the plug and the perforation.

25. The apparatus of claim 23, wherein a first of the at least two elements comprises a plug composed of a dissolvable metal as one of the different materials, the plug affixed at the at least one perforation; and wherein a second of the at least two elements comprises a coating composed of a dissolvable material as another of the different materials and coating the plug. A method of controlling fluid flow from a borehole, the comprising:

running a basepipe into the borehole, the basepipe having a throughbore and

defining at least one perforation, the throughbore conveying the fluid flow, the at least one perforation communicating the through-bore with the borehole;

at least temporarily preventing fluid communication through the at least one

perforation with at least one barrier disposed at the at least one perforation, the at least one barrier being resistant to pressure and being dissolvable over time; and

allowing fluid communication through at least one nozzle disposed at the at least one perforation after dissolution of the at least one barrier.