RU2599751C1 - Assembly for gravel packing by "from-toe-to-heel" method and by reverse circulation of excess suspension as per john p.broussard and christopher a.hall method - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: group of inventions relates to production of gravel filters for oil and gas wells. Device includes a housing located in the well and forming a through channel, one or more sections arranged on the housing. Each section comprises an insulation element arranged on the housing and insulating an annular space around the section from other sections, a window on the housing, which provides the fluid medium flow between the through channel and the annular space, a filter arranged on the housing and interconnected with the annular space, a gate lock arranged on the housing and preventing the fluid flow from the through channel to the filter, a working string, which forms the outlet, controlled in the housing in relation to each section. Working string in the first operating mode delivers the composition for processing the bottomhole zone from the outlet to the annular space section through the window. Working string in the second operating mode receives the reverse circulation from the through channel to the outlet.

EFFECT: gravel packing process is simplified.

33 cl, 24 dwg

Description

[0001] This application is a partial continuation of US application 12/913981, filed on October 28, 2010 under the name "Ronald van Petegam and John P. Broussard and Gravel Packing Assembly for Bottom-Up / Toe-to-Heel Stuffing" and US Application 13/670125, filed November 6, 2012, entitled “Multi-Fractured Hydraulic fracturing system with a filter” by John P. Broussard, Ronald van Petegham, and Christopher A. Hall, which are incorporated herein by reference.

BACKGROUND

[0002] Some oil and gas wells are completed in loose formations that contain loose fine particles and sand. When fluids are extracted from these wells, loose fine particles and sand can be transported with the produced fluids and can damage equipment such as electric submersible pumps (ESPs) and other systems. For this reason, fine filters for sand control may be required.

[0003] Horizontal wells that require sand control are typically open hole completions. In these horizontal open-hole wells, predominantly known stand-alone sand filters are used. At the same time, operators also use gravel packing in these horizontal open-hole wells to solve the issue of sand control. Gravel is a special material from a calibrated particle, such as fractions of sand or proppant, which is packed around a sand filter in the annular space of the well. Gravel acts as a filter to keep any fine-grained particles and sand from the formation from being transported with the produced fluid.

[0004] According to the prior art, the gravel packing system 20 shown in FIG. 1A extends from the packer 14 from the bottom side from the casing 12 into the well 10, which is a horizontal open-hole well. To combat sand, operators try to fill the annular space between the assembly 20 and the borehole 10 with gravel (particle material) by pumping a suspension of fluid and gravel into the borehole 10 to fill the annular space. For horizontal open hole 10, operators can use the alpha-beta wave method (or water packing) to fill the annular space. This method uses a low viscosity fluid, such as an injection fluid, to transport gravel. The system 20 in FIG. 1A is such an alpha beta type.

[0005] First, the operators install the wash pipe 40 into the filter 25 and pump the slurry consisting of fluid and gravel down the work string 45. The slurry passes through the window 32 in the transfer sleeve 30 into the annular space between the filter 25 and the well 10. As shown, the transfer the clutch 30 is located directly on the bottom side of the packer 14 gravel packing and on the side of the mouth of the filter 25. The window of the transfer clutch 32 deflects the flow of suspension from the inner working column 45 into the annular space from the bottom of the packer 14. At the same time, another window of the transfer clutch 34 diverts the flow of drilling fluid from the flushing pipe 40 to the mouth of the annular space of the casing from the packer 14.

[0006] As soon as the work begins, the suspension leaves the window 32 of the transfer clutch in the annular space. The transporting fluid in the suspension then seeps through the formation and / or through the filter 25. However, the filter 25 prevents the gravel in the suspension from flowing into the filter 25. The fluids alone passing through the filter 25 can then be returned through the transfer clutch window 34 into the annular space above the packer 14.

[0007] As soon as the fluid flows out, the gravel falls out of the suspension and is first packed along the low side of the annular space of the well. Gravel is collected in stages 16a, 16b, etc., which advances from heel to toe in what is called an alpha wave. Since the well 10 is horizontal, gravitational forces prevail in the formation of alpha waves and gravel settles along the lower side at an equilibrium height along the filter 25.

[0008] When the gravel packing process in the alpha wave is completed, gravel begins to collect in stages (not shown) of the beta wave. This forms along the top of the filter 25, starting from the toe, and advances towards the heel of the filter 25. Again, the gravel transporting fluid can pass through the filter 25 up the wash pipe 40. To complete the gravel packing process in beta wave, you need to have sufficient speed fluid to maintain turbulent flow and to move gravel along the upper side of the annular space. To recycle after this point, operators must mechanically reconfigure the transfer sleeve 30 to be able to flush the pipe 40.

[0009] Although the alpha-beta method can be economical due to the low viscosity of the carrier fluid and the usual types of filters that can be used, some situations may require a viscous fluid packing method that uses an alternative route. In this method, shunts located on the filter deflect the injected packing suspension along the outer surface of the filter. FIG. 1B shows an example of a system 20 having shunts 50 and 52 (only two of which are shown). Typically, shunts 50/52 for transportation and packing are attached eccentrically to the filter 25. Transport shunts 50 transfer the suspension to the packing shunts 52 and the suspension exits the nozzles 54 located on the packing shunts 52. Using shunts 50/52 for transporting and packing the suspension, the process gravel packing can avoid areas of high leakage in the well 10, which could cause plugging and impair gravel packing.

[0010] According to the prior art, the gravel pack assemblies 20 for both methods of FIG. 1A-1B have a number of problems and difficulties. During the gravel packing process in a horizontal well, for example, the 32/34 transfer clutch windows may need to be reconfigured several times. During the hydraulic fracturing process with the installation of a gravel pack, the slurry pumped under high pressure and flow rate can sometimes be dehydrated inside the tool of the transfer clutch 30 of the system and the associated slip clutch (not shown). Strictly speaking, settled sand or dehydrated slurry may adhere to service tools and may even clog a well. In addition, the transfer clutch 30 undergoes erosion during hydraulic fracturing and gravel packing processes, and the transfer clutch 30 can adhere to the packer 14, which can create extremely difficult fishing operations.

[0011] In order to cope with gravel packing, in some open-hole wells, an open-hole gravel packing system with a back-up window in an uphole was developed, as described in SPE 122765, entitled “The world's first open-hole gravel packing with a back-up window in an upstream trunk and with swellable packers ”(Jensen et al. 2009). This system allows gravel packing of the ascending hole of an open-hole well using a window located in the direction of the toe of the well.

[0012] In cased hole processes, it is very common to mount several gravel pack installations in a process referred to as “stacked packs”. Each zone is addressed in a separate process for punching, installing gravel packing equipment, pumping gravel, and then the process is repeated. Other multilayer gravel packing systems have been developed, which are commonly referred to as single-track, multilayer systems. These systems are a conventional structure in which they introduce a suspension into the annular space outside the filter from the upper side of the filter and pump the fluid towards the bottom of the zone. In addition, these systems have been specifically used for cased hole applications and have only recently been adapted for use in open cased wells.

[0013] The subject matter of the present disclosure is directed to overcoming or at least reducing the effects of one or more of the problems described above.

SUMMARY OF THE INVENTION

[0014] A multi-layer device and method is used to process the formation. The device can be used for reservoir treatments, such as hydraulic fracturing processes, hydraulic fracturing with the installation of a gravel filter, gravel packing processes or other processes. The device includes a housing (for example, a tubular structure, a liner, production string, etc.) and a working string. The body of the assembly is located in the well and forms a through channel. One or more sections are located on the housing, and each one or more sections contains an insulating element, a window, a filter, and a shutter.

[0015] An isolation element located on the housing isolates the annular space of the well around the section from other sections. A window located on the housing allows fluid to communicate between the through channel and the annular space of the well, and a filter located on the housing communicates with the annular space of the well. The shutter located on the housing, at least, prevents the communication of fluid from the through channel to the filter.

[0016] The work string forms an outlet and is manipulated in the housing relative to each section. The working column in the first mode of operation delivers the composition for processing the near-barrel zone from the exit to the section of the annular space of the well through the window. The working column in the second mode of operation receives reverse circulation from the through channel to the output.

[0017] In one embodiment, a window for a given one of the one or more sections is located toward the toe, and a filter for the section is located toward the heel. During processing, the window delivers the suspension, as a composition for processing the trunk area and gravel packing the annular space of this section from toe to heel. The filter filters the drilling fluid from the suspension into the through channel of the housing.

[0018] In another embodiment, a window for a given one or more sections is located towards the heel, and a filter for this section is located towards the toe. During processing, the window delivers the suspension as a composition for processing the trunk area and gravel packing the annular space of this section from heel to toe. The filter filters the drilling fluid from the suspension, and the section has a bypass that delivers the drilling fluid into the through channel through the housing window from the mouth side.

[0019] In one embodiment, the window comprises a flow valve configured to selectively operate between open and closed positions, allowing and preventing fluid from flowing between the through channel and the annular space of the well. The flow valve may include a sleeve configured to move in the through channel between: (a) a closed position that prevents the fluid from communicating through the window and, (b) an open position that allows the fluid to communicate through the window. The work string can be made so as to at least open the flow valves of one or more sections. For example, the work string may have a power tool configured to open and close the flow valves of one or more sections in the through channel on the same flight.

[0020] In one embodiment, the shutter is configured to selectively act between: (a) a closed position that prevents fluid from communicating between the through channel and the filter; and (b) an open position that allows fluid to communicate between the through channel and the filter. For example, the shutter may include a sleeve configured to move in the through channel between: (a) a closed position that prevents fluid from communicating through at least one flow window in the housing, at least one flow window in communication with a filter and, (b) an open position allowing fluid to communicate through at least one flow window.

[0021] In another example, the shutter may include a one-way valve located in fluid communication between the filter and the through passage, wherein the one-way valve in the open position allows fluid to flow from the filter into the through passage, and in the closed position, prevents the flow of fluid from the through channel to the filter.

[0022] The foregoing summary is not intended to summarize each possible embodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1A-1B illustrate a gravel pack assembly in accordance with the prior art.

[0024] FIG. 2A-2B show a multilayer system with a filter in accordance with the present disclosure during descent into a well for a flushing process.

[0025] FIG. 3A-3B show the system during installation and testing of the packer.

[0026] FIG. 4A-4B show the system during gravel packing processes.

[0027] FIG. 5A-5B show the system while filling the annular space around the shoe area to drain excess slurry.

[0028] FIG. 6A-6B show another multilayer filter system in accordance with the present disclosure having alternative parallel connections for gravel packing processes.

[0029] FIG. 7 shows a multilayer filter system having filter sections separated by packers.

[0030] FIG. 8 illustrates a multilayer filter system in accordance with the present disclosure, located in an open hole and using a work string in combination with valves and flow devices.

[0031] FIG. 9 illustrates a multilayer filter system of FIG. 8 having overflow pipes.

[0032] FIG. 10A illustrates a partial cross-sectional view of a flow device for open multi-layer filter assembly assemblies.

[0033] FIG. 10B illustrates a detailed view of a non-return valve device for the flow device of FIG. 10A.

[0034] FIG. 10C illustrates an isolated, partial cross-sectional view of the flow device of FIG. 10A.

[0035] FIG. 11A-11B illustrate another multilayer filter system in accordance with the present disclosure, located in an open hole and using a work string in combination with valves and flow devices.

[0036] FIG. 12A-12D illustrates yet another multilayer filter system in accordance with the present disclosure having a toe to heel configuration.

DETAILED DESCRIPTION

[0037] FIG. 2A-2B show a multilayer system 200 with a filter in accordance with the present disclosure, launched into the well. System 200 can be used for formation treatments, such as fracturing processes, a fracturing process with a gravel pack, gravel packing processes, or other processes. The system 200 includes a production casing or liner 225 (e.g., tubular structure or housing) that extends into the well 10 from the liner packer 14 supported in the casing 12. This well 10 may be a horizontal or deviated open hole. The system 200 also has a hydraulic service tool 202 added to the packer 14, and has an inner work string 210 attached to the service tool 202.

[0038] As shown in FIG. 12B, liner 225 may have a column shoe 220 at its end. Meanwhile, over its entire length, the shank 225 may have one or more sections of filters 240A-B (Fig. 2B) and one or more perforated casings 230A-B. Typically, the perforated housings 230A-B can be arranged side by side or combined into one or more sections of filters 240A-B. As discussed below, one or more filter sections 240A-B and perforated casings 230A-B are used to deliver the suspension to one or more packing points for the gravel packing process.

[0039] Each of the perforated housings 230A-B has a housing or flow windows 232A-B for deflecting flow. Inside, each of the perforated housings 230A-B has sockets 234 formed above and below the outlet ports 232A-B for sealing with the remote end of the inner work string 210, as described below. To prevent erosion, flow windows 232A-B on perforated casings 230A-B may have a skirt, such as skirt 236 for flow windows 232A on perforated casings 230A.

[0040] The flow openings 232B at the top of one of the perforated housings 230B communicate with alternate path devices 250 located along the length of the lower section of the filter 240A. These alternate path 250 devices may be shunts, tubes, concentric tubes or other devices known in the art to provide an alternative trajectory for the slurry. However, for the purposes of the present disclosure, alternative path devices 250 are referred to herein as shunts for simplicity. Typically, shunts 250 communicate from the flow openings 232B to the side openings 222 in the direction of the distal end of the system 200 or other directions for use during process steps.

[0041] As shown in FIG. 2B, the inner work string 210 extending from the service tool 202 (FIG. 2A) is located through the filter sections 240A-B of the system 200. (The inner work string 210 may optionally have a return cone to reduce circulation pressure). At the end of the filter sections 240A-B, the system 200 has a shoe area 220 with a column shoe 226 and a socket 224. The column shoe has a non-return valve 226, a sleeve, and the like. (not shown) that allow flushing or circulating fluid to flow around the outside of the filter sections 240A-B when lowered into the well and before the packer 14 is installed.

[0042] At its distal end, the inner workstring 210 has outlet openings 212 insulated with gaskets 214. When lowering, one of the gaskets 214 can seal the end of the inner workstring 210 inside the shoe area 220, as shown in FIG. 2B. Thus, the fluid pumped into the bottom of the well through the inner working string 210 may exit a non-return valve (not shown) in the column shoe 226 at the end of the shoe zone 220 to flush the well 10.

[0043] During the gravel packing process, however, exhaust ports 212 can be positioned and sealed with gaskets 214 in perforated housings 230A-B located between each of the filter sections 240A-B. In particular, gaskets 214, located on both sides of the outlet windows 212 of the column, seal the inner seats 234 on the perforated bodies 230A-B. The gaskets 214 may use elastomeric or other types of seals located on the inner workstring 210, and the sockets 234 may be polished sockets or surfaces inside the housings 230A-B to engage the gaskets 214. Although shown with this configuration, the opposite arrangement may be used: gaskets - on the inside of the enclosures 230A-B and the sockets - on the inner working string 210.

[0044] When the fluid is pumped through the inner work string 210, the injected fluid exits the string 210 and through the flow ports 232A-B on the perforated casings 230A-Depending on the location of the string 210 with respect to the flow windows 232A-B. In this arrangement, the flow openings 232A in the lower perforated housing 230A direct the suspension directly into the annular space, while the flow openings 232B in the upper perforated housing 230B direct the suspension to the shunts 250, as described below. Other similar designs may be used. In any case, this selective arrangement and seal between the column 210 and the casings 230A-B, which changes the paths of the fluid to deliver the suspension into the annular space around the filter sections 240A-B during the gravel packing process, is discussed in more detail below.

[0045] As shown in FIG. 2A-2B, the system 200 is lowered into the well for flushing. The service tool 202 sits on an uninstalled packer 14 in the casing 12 and the gaskets 204 on the service tool 202 are not sealed in the packer 14 in order to transmit hydrostatic pressure. The distal end of the inner work string 210 fits through the filter sections 240A-B, and one of the gaskets of the string 214 is sealed against the receptacle 224 near the shoe 226. Operators pump the fluid in a closed system down the inner work string 210, and the circulating fluid flows out from the non-return valve in the column shoe 226, up the annular space and around the unpacked packer 14.

[0046] As shown in FIG. 3A-3B, the operators then install and test the packer 14. To install the packer 14, the operators pump fluid into the well to hydraulically or hydrostatically install the packer 14 using processes well known in the art, although other methods of installing the packer may be used. To test packer 14, gaskets 204 on service device 202 rise into the packer opening after being released from packer 14. Operators then check packer 14 by applying pressure to casing 12. Fluid passing through any pressure leak on packer 14 will go into formation around sections of filters 240A-B. In addition, any leaking fluid will pass into the outlets of the inner work string 212 and up to the surface through the inner work string 210. Regardless, system 200 allows operators to maintain hydrostatic pressure on the formation during these various stages of operation.

[0047] After the packer 14 is installed and tested, the operators begin the gravel packing process. As shown in FIG. 4A-4B, operators raise the inner work string 210 to establish themselves in the first position of the gravel pack. As shown in FIG. 4B, column gaskets 214 engage in sockets 234 around lower windows 232A below the lower section of filter 240A. When this is done, the windows of the tool 212 communicate with the windows of the casing 232A.

[0048] When manipulating the inner workstring 210, the operators preferably give a signal to the surface that the outlet ports 212 are in a predetermined position, whether it is an empty position, a suspension circulation position, or a pumping position. One way to achieve this is to measure tensile or compression on the surface to determine the position of the inner work string 210 relative to the perforated housings 230A-B and sockets 234. This and other processes known in the art can be used.

[0049] With windows 212 / 232A insulated by interlocked gaskets 214 and sockets 234, operators pump a slurry consisting of transporting fluid and gravel downward of the inner workstring 210 in a first direction to the windows of the column 212. The slurry exits the windows of the pipe 212 and through the windows casing 232A into the annular space of the open hole. The transporting fluid in the suspension then flows through the formation and / or through the filter sections 240A-B along the length of the system 200. However, the filter sections 240A-B prevent the gravel in the suspension from flowing into the system 200. Thus, the fluid passes alone through the filter sections 240A-B and returns through the annular space of the casing above the packer 14.

[0050] As described herein, gravel may be packed in an annular space in an alpha beta wave, although other variations may be used. When the fluid flows out, for example, gravel falls out of suspension and is first packed along the bottom side of the annulus in the well 10. Gravel is collected in steps that move from the toe (near casing 230A) to the heel in the alpha wave. Gravitational forces prevail in the formation of alpha waves, and gravel settles along the underside at the height of equilibrium along the filter sections 240A-B.

[0051] After the alpha wave, well 10 is filled in beta wave along system 200. Gravel begins to collect in beta wave along the upper side of filter sections 240A-B, starting from the heel (near packer 14) and advancing to the fore of assembly 200. Again gravel transporting fluid may flow through the filter sections 240A-B and up the annular space between the inner work string 210 and the liner 225.

[0052] In the end, the operators reach the desired state while pumping the suspension into the windows 232A in this perforated casing 230A. This desired state can be determined by a specific increase in pressure levels and may be referred to as “sand loss” in some contexts. At this stage, the operators raise the inner work string 210 again, as shown in FIG. 5A-5B. Gaskets 214 now sit in sockets 234 around windows 232B on the next perforated casing 230B between filter sections 240A-B. The operators pump the slurry downward of the inner workstring 210 again in a first direction to the exit window 212, and the slurry flows out of the windows of the pipe 212 and through the windows of the casing 232B.

[0053] Typically, the suspension may optionally flow from the windows 232B into the surrounding annular space. This is possible if one or more of the 232B windows communicates directly with the annular space and does not communicate with one of the alternate path devices or a shunt 250. Nevertheless, a suspension may flow from the 232B windows into an alternate path device or a shunt 250 for placement somewhere in the environment. annular space. Although the shunts 250 are depicted in a specific way, any desired location and number of transport and packing devices can be used, for an alternate route to feed and deliver the suspension.

[0054] Depending on the implementation, this second step of pumping the suspension can be used for further gravel packing of the well. However, as shown in the current implementation, pumping the slurry through shunts 250 allows operators to pump the excess slurry from the inner work string 210 into the well without reversing the flow in the string 210 from the direction of the first flow (i.e., in the direction of the windows of the string 212). This is different from the reverse direction of the flowing liquid down the annular space between the column 210 and the casings 230A-B / filters 240A-B for pumping excess suspension from the column 210.

[0055] As shown in FIG. 5B, the slurry passes from window 212, through flow openings 232B and through shunts 250. From shunts 250, the slurry then exits from side windows or nozzles 254 in shunts 250 and fills the annular space around shoe area 220. This provides gravel packing with an alternative path different from the main toe-to-heel system. Thus, shunts 250 attached to the perforated casing 230B above the lower section of the filter 240A can be used to place excess gravel from the work string 210 around the shoe area 220. The shunts 250 carry the slurry down the lower section of the filter 240A so that a flush pipe is not required on end of section 240A. However, bypass 258 defined at the bottom location of system 200 (or elsewhere) allows fluid to return during this process. This bypass 258 may be a non-return valve, part of a filter, a sleeve, or other suitable device that allows the flow of drilling fluid, rather than gravel from the well, to enter system 200. In fact, bypass 258 as part of the filter can be any desired length along shoe zone 220 depending on the implementation.

[0056] At some point, the process may reach a “sanding out” state or increasing pressure while the slurry is being pumped into windows 232B. At this point, a valve, rupture disk, or other shutter device 256 in shunts 250 may open so that the gravel in suspension can then fill the inside of the shoe area 220 after pumping excess around the shoe area 220. Thus, operators can pump excess gravel from inside the shoe zone 220. Once this happens, the drilling fluid can exit the lower section of the filter 240A, through the packed gravel in the annular space, and back through the upper section of the filter 240B to move to the wellhead. In other designs, the lower perforated casing 230A may have a bypass, another shunt, or the like (not shown) that can be used to deliver brown mud past the gaskets 214, sockets 234, and the mouth.

[0057] The previous system 200 filled the annular space of an open-hole well with alpha beta waves, and then filled the annular space around the toe along an alternate path. As shown in FIG. 6A-6B, system 200 may use an alternate path accessory or shunt 260 to fill the annular space of an open hole during circulation during gravel packing. In this design, the operation of the system 200 is similar to that discussed above. Again, the system 200 has one or more perforated housings 230A-B to exit the suspension and has one or more sections of filters 240A-B.

[0058] When operators raise the inner workstring 210 to position it for the gravel packing process shown in FIG. 6B, operators pump at least some slurry into the annular space of an open hole using additional shunts 260 in an alternative gravel pack path. Shunts 260 may be used as an exception. Alternatively, the slurry can be pumped through one or more windows of housing 232A simultaneously. Using the design of shunts 250/260 and open flow openings 232, system 200 can fill gravel with toe to heel, heel to toe, and combinations thereof.

[0059] As can be seen in FIG. 2A-6B, the disclosed system 200 may be used in a number of versatile gravel packing methods for annular borehole space. For example, outlet ports of column 212 may be located in one or more different perforated gravel packs 230A-B around gravel packs around sections of filters 240A-B in an alpha beta wave, or alternatively. In addition, the inner working column 210 can be moved into several casings 230A-B for stuffing a single zone of several points or gravel packing of the same zone from the first direction and then from another direction (for example, the first from the bottom up, and then from top to bottom, using shunts 250/260).

[0060] In addition, the inner working column 210 can be used to pump solutions for treating the near-stem zone or other types of solutions into the surrounding zone. For example, system 200 in FIG. 2A-6B can be used to perform hydraulic fracturing with installing a gravel pack from one point and then gravel packing (through shunts 250 and / or 260) from another point along the filter sections 240A-B. In hydraulic fracturing with the installation of a gravel filter, operators perform fracturing treatment, delivering large volumes of graded sand, proppant, or the like. into the annular space and into the formation at pressures exceeding the hydraulic fracturing gradient. Graduated sand or proppant fills faults in well 10 to keep faults open. After fracturing, the operators can then perform a gravel pack operation to fill the annular space with gravel. Alternatively, gravel packing and fracturing treatments may be performed at the same time.

[0061] In a hydraulic fracturing design with a gravel pack, the disclosed system 200 can deliver a hydraulic fracturing solution and gravel slurry through several perforated casings 230A-B into the annular space around the filter sections 240A-B. Dispersing the hydraulic fracturing solution and suspension through multiple 232A-B windows can provide more uniform distribution across a large area. For part of the hydraulic fracturing process, the hydraulic fracturing solution may exit the lower perforated casing 230A and the drilling fluid may pass through a filter section 240B adjacent to the annular space of the casing until the fracture is completed. After that, the inner working column 210 can be moved into the upper perforated casing 230B so that the gravel slurry can flow through shunts 250 and / or 260 for gravel packing of the annular space. An inverse process can be done in which the fracturing solution can exit into the upper casing 230B, so that gravel packing can be done primarily in the lower casing 230A using gravel packing from toe to heel.

[0062] When used for hydraulic fracturing / gravel packing, system 200 may reduce the chances of adhesion. Since system 200 may have a smaller volume area around exit points, there may be less chance of proppant sticking around gravel pack windows 212. Since the suspension exits near the end of the inner work string 210, only a short portion of the pipe should be pulled up through the remainder of the suspension or dehydrated sand that may be left. If adhesion occurs around the gravel pack windows 212, a cut-off disconnector (not shown) can be integrated into the inner work string 210 so that the bottom of the inner work string 210 can be disconnected from the top of the inner work string 210. This will allow the inner work string column 210 subsequent movement.

[0063] Extending the universality of the disclosed system, FIG. 7 shows a system 300 segmented by several blocked separate zones. Again, system 300 can be used to treat formations, such as fracturing processes, a fracturing process with a gravel pack, gravel packing processes, or other processes. The system 300 includes a production string or liner 325 (eg, tubular structure or housing) and includes an internal working string 310. The liner 325 extends into the well 10 from the liner packer 14, which is held in the casing 12. Again, this well 10 may be a horizontal or deviated open hole.

[0064] The shank 325 has several sections of gravel pack 302A-C, separated by 360/370 packers. 360/370 packers and 302A-C gravel pack sections are deployed in the well in one run. A single 360/370 packer or a combination of 360/370 packers can be used to isolate 302A-C gravel pack sections from each other. Any suitable packers may be used, and they may, for example, include hydraulic or hydrostatic packers 360 and swell packers 370. Each of these 360/370 packers may be used in combination with each other, as shown, or 360 or 370 packers. can be used separately.

[0065] Hydraulic packers 360 provide more rapid zone isolation when installed in the well 10 to stop the progress of gravel packing in isolated zones. For their part, the swellable packers 370 can be used for long-term isolation of the zone. Hydraulic packers 360 can be mounted hydraulically from the inner workstring 310 and their seal designs 314, or packers 360 can be mounted using cam couplings (not shown) in packers 360 with pushers (not shown) on the inner workstring 310.

[0066] Each section of gravel pack 302A-C may resemble an assembly 200, as discussed above in FIG. 2A-6B. Thus, each gravel pack section 302A-C has two filters 340A-B, alternative path devices or shunts 350 and windows 332A-B, and may have perforated casings and other components discussed previously. Further, the inner working column 310 is deployed in the first section of the gravel pack 302A and flushes the outlet windows of the column 312, isolates with its gaskets 314 the bottom consumable windows 332A for gravel packing and / or hydraulic fracturing of the first section of the gravel pack 302A. Then, the inner work string 310 can be moved so that the outlet ports 312 are isolated with the upper flow ports 332B connected to the shunts 350 to fill the annular space around the lower end of the first section of the gravel pack 302A. A similar process can be repeated up the wellbore for each section of gravel pack 302A-C, separated by 360/370 packers. Using the processes described above, the excess slurry can be pumped from the inner workstring 310 into the annular space before the workstring 310 moves between sections 302A-C.

[0067] Turning now to FIG. 8-9, another multilayer filter system 400 includes an inner work string 410 and a filter assembly 420. Again, system 400 may be used to prepare the formation, such as fracturing processes, a fracturing process with a gravel pack, gravel packing processes, or other processes. The filter assembly 420 has a production string or liner 425 (eg, tubular structure or housing) that extends in the borehole 10 from the liner packer 14, which is supported in the casing 12. At its end, the liner 425 may have a column shoe 422 or the like him and sections 428A-C located on the shank 425, each of which has an isolation element 429, a flow valve 430, a filter 440 and a shutter 450.

[0068] As shown in FIG. 8, a work string 410 is located in the assembly 420 to open various valves 430 and process portions of the formation. As shown, the workstring 410 has external gaskets 416 located adjacent to the outlet windows 412. The discarded ball 414 can be installed in a remote socket of the workstring 410 to divert the fluid flow down the workstring 410 from the outlet windows 412 and to open the windows 432 in the valve 430 to prepare the surrounding formation.

[0069] Flow devices 440 located in the assembly 420 include a downhole filter 446 and gates 450 (ie, one-way or non-return valves, sliding couplings, etc.). Like one-way or non-return valves, the valves 450 can be manufactured in a variety of ways and may include ball, poppet or disk non-return valves that are concentrically or eccentrically mounted on the outer radius of the filter main pipe. Valves 450 may be part of a casing that directs flow into the main pipe, and may be attached to downhole filters to provide a fluid flow filtered from solids. Preferably, a plurality of closures 450 can be installed on each joint in order to reduce and even eliminate the pressure drop through the filter joints in order to facilitate the full development of the beta wave during gravel packing. Alternatively, gates 450 may be installed in the main pipe and may provide flow into the casing mounted on the radial outer surface of the main pipe and attached to the downhole filter 446.

[0070] The process for the system 400 of FIG. 8 includes the descent of the filter assembly 420 into the well and the installation of packers 429 to create several isolated sections 428A-C at the bottom of the annular space of the well 15. After the packers 429 are installed, operators apply the fracturing treatment sequentially for each of the isolated sections 428A -C by selectively opening selective valves 430 and pusher 418 on work string 410.

[0071] Typically, the pusher 418 may be a "B" pusher to shift the inner sleeve 434 in the valve 430 relative to the windows of the valve 432. Thus, opening this valve 430 includes engaging the pusher 418 in the corresponding profile of the inner sleeve of the valve 434 and moving the inner the couplings 434 with the working string 410 to the open position so that the through channel of the assembly 425 communicates with the annular space of the well 15 through the currently open windows 432.

[0072] After this valve 430 has been opened, the gaskets 416 on the workstring 410 may mesh and seal against the inner seats 438, surfaces, gaskets, or the like. in the valve 430 or elsewhere in the assembly 420 on both sides of the open windows 432 - from the mouth and bottom. The gaskets 416 can use elastomeric or other types of seals located on the inner workstring 410, and the sockets 438 can be polished sockets or surfaces inside the valve 30 or other parts of the filter assembly 420 to engage the gaskets 416. Although shown in this configuration, you can use reverse location - with gaskets on the inside of the valve 430 or assembly with filter 420 and with sockets on the work string 410.

[0073] After the working column 410 is installed, the composition for processing the barrel region flows through the through channel 415 of the working column 410 to the sealed and open windows 432 in the valve 430. The composition for processing the barrel region flows through the outlet windows 412 in the working column 410 and through open windows 432 to the annular space 15 surrounding the borehole, which allows the composition for processing the near-stem zone to interact with an adjacent zone of the formation.

[0074] After processing is completed for a given zone 428A-C, operators manipulate the work string 410 to engage the pusher 418 in the valve 430 to close the windows 432. For example, the pusher 418 may engage with another suitable profile on the inner sleeve 434 a valve 430 to move the sleeve 434 and close the windows 432. At this point, the work string 410 can be moved to the assembly 420 to open the other of the valves 430 to perform processing. Operators repeat this process up to assembly 420 to process all sections 428A-C. Once processing is complete, system 400 may not need a cleaning flight.

[0075] The multi-layer system 400 of FIG. 8 may have higher performance than a conventional single-track multi-layer system and may improve reservoir performance. System 400 may be of any suitable length and size, and it makes it possible to reduce the diameter of the casing, does not require perforation, and does not require a cleaning flight. Consideration should be given to possible adhesion to the work string 410 during operation and packing of the annular space that may occur for a particular implementation.

[0076] In another embodiment, the multi-layer system with filter 400 of FIG. 9 also has a work string 410 and a filter assembly 420, as in the previous embodiment shown in FIG. 8. In addition to all of the same components, this system 400 has slurry dewatering or bypass pipes 480 located along various sections 428A-C.

[0077] During a treatment process similar to that described above, pipes 480 help dehydrate the slurry intended for hydraulic fracturing or gravel packing of the annular space of the well 15 sections 428 during hydraulic fracturing with the installation of a gravel filter or gravel packing process. In addition, pipes 480 can act as a bypass for drilling fluid during the process. When the composition for processing the near-barrel zone flows from the working string 410 installed in the valve 430 through open windows 432 into the annular space of the well 15, the well filter 446 filters the drilling fluid from the annular space 15, and the drilling fluid can flow into the assembly 420 from the downhole side parts from engagement of the drill string 410 in the assembly 420. Tubes 480 may thus allow this drilling fluid to flow from the bottomhole portion of the assembly 420 into the micro-ring space between the drill string 410 and the inside side collecting unit 420 from the mouth of the sealed engagement of the work string 410 with windows 432. From this point the drilling fluid may flow to the surface.

[0078] The multi-layer system 400 of FIG. 9 may be superior to conventional single-track multi-layer system 400 and may improve reservoir performance. In addition, the system 400 can be of any length and size, makes it possible to reduce the diameter of the casing, does not require perforation, does not require a cleaning flight, and can give a good packing of the annular space. Consideration should be given to the possible sticking of work string 410 for a particular implementation.

[0079] As noted above, the multilayer system 400 may use flow devices 440 located in the assembly 420, wherein the flow device 440 includes a downhole filter 446 and a shutter 450 (i.e., single-pass or non-return valves). Turning now to FIG. 10A-10B, one embodiment of a flow device 540 that can be used with the disclosed systems 400 is shown in partial cross-section and in detail, respectively. Flow device 540 is a filter connection having a filter jacket 550 (i.e., a downhole filter) and an inflow control device 560 (i.e., a one-way or non-return valve) located on the main pipe 542. (Fig. 10C shows an inflow control device 560 in isolated form without main pipe 542 and filter jacket 160).

[0080] The flow device 540 is deployed on a completion column (422: FIG. 8-9) with a filter jacket 550, typically installed upstream of the inflow control device 560, although this is not absolutely necessary. The main pipe 542 forms a through passage 545 and has a transfer connector 546 at one end for connection to another connection or the like. The other end 544 may be connected to a transfer sleeve (not shown) of another connection on the completion column (422). Inside the through channel 545, the main pipe 542 forms the windows of the pipe 548, where the inflow control device 560 is located.

[0081] As noted above, the 560 inflow control device may be similar to FloReg deploy-assist (DA), a device available from Weatherford International. As best shown in FIG. 10B, the inflow control device 560 has an external sleeve 562 located around the main pipe 152 in place of the windows of the pipe 548. The first end ring 564 is sealed to the main pipe 542 with a sealing element 565, and the second end ring 566 is attached to the end of the filter jacket 550. B generally, the sleeve 562 forms an annular space around the main pipe 542 that connects the windows of the pipe 548 to the filter jacket 550. The second end ring 566 has flow openings 570 that divide the sleeve's annular space in the first interior twe 576, with a filter 550 from a second interior space 578 communicating with the windows of the pipe 548.

[0082] For its part, the protective jacket of the filter 550 is located around the outside of the main pipe 542. As shown, the protective jacket of the filter 550 may be a wound wire mesh having rods or ribs 554 located longitudinally along the main pipe 542 with turns of wire 552 wound around it to form various intervals. Fluid can flow from the surrounding annulus of the well into the annular gap between the filter jacket 550 and the main pipe 542. Although shown as a wire winding filter, the filter jacket 550 can use any other form of filter assembly, including metal screens, packing filters , sheath protective filters, expandable anti-sand filter, or filters of other designs.

[0083] Internally, the inflow control device 560 has a plurality (eg ten) of flow openings 570. Instead of providing a predetermined pressure reduction along the filter jacket 550 with several open or closed nozzles (not shown), the inflow control device 560, as shown in FIG. 10A-10C may not contain commonly used throttling nozzles and shut-off nipples for internal flow channels 570. However, flow windows 570 may be relatively non-throttled flow channels and may not have conventional nozzles, although this implementation may use such nozzles if the pressure drop preferably from a filter jacket 550 to a main pipe 542.

[0084] Inside, however, the inflow control device 560 comprises window isolation balls 572 that allow the device 560 to operate as a one-way or non-return valve. Depending on the direction of flow or pressure difference between the interior spaces 576 and 578, the insulation balls of the window 572 can move to the open position (to the right in FIG. 10B), allowing fluid to flow from the inside of the filter 576 to the inside of the pipe 578, or into the closed position (to the left in FIG. 10B against the end of the socket 574 of the flow window 570), preventing the flow of fluid from the interior of the pipe 578 to the inside of the filter 576.

[0085] Typically, an inflow control device 560 can facilitate fluid circulation during well deployment and cleanup and can be used in deployments without underground well repair and installation of open-hole packers. In deployment, for example, insulation balls 572 maximize fluid circulation through the completion shoe (420: FIGS. 8-9) of the hydraulic fracturing system (20) to aid in the efficient deployment of the injection string (22) and system (20). When casing components (562, 564, 565, 566) are located on the main pipe 540, the insulating balls 572 are held in place. During initial installation and operation, insulating balls 572 can prevent formation pulsation, thereby reducing formation damage. In some designs, insulation balls 572 in device 560 can be made to wear over a period of time that provides access to an interval for underground repair activities, such as intensification.

[0086] If a pressure drop from the filter jacket 550 to the main pipe 542 is desired, the flow ports 570 may include nozzles (not shown) that throttle the flow of filtered fluid (ie, inflow) from the filter jacket 550 to the interior of the pipe 578. For example, the inflow control device 560 may have ten nozzles, although all of them may not be open. Operators can set a number of these nozzles open on the surface to configure the device 560 for use in the bottom hole in this implementation. Depending on the number of nozzles open, device 560 can thus produce a customizable pressure drop along the column of such flow devices 540.

[0087] FIG. 11A-11B illustrate another multilayer filter system 400 in accordance with the present disclosure that is used to complete an open hole. Again, system 400 can be used to treat formations, such as fracturing processes, a fracturing process with a gravel pack, gravel packing processes, or other processes. As with some previous designs, system 400 has a work string 410 that is located in a filter assembly 420 to open various valves 430 and process parts of the formation, but work string 410 in this design does not seal the inside of the assembly 420 while providing processing at various points in the reservoir.

[0088] As shown, an auxiliary packer 17 may be used between the production string 410 and the casing 12 to isolate the inner through passage 425 of the assembly 420. As also shown, the production string 410 has a service tool 417 located above the liner packer 16. Service tool 417 can be used to hydraulically mount packer 16. Regardless of the configuration used, the wellhead components of system 400 can be used for circulation, compression, and inverse processes known in the art.

[0089] The work string 410 has one or more outlet ports 412 and has hydraulically actuated pushers 418a-b. Both pushers 418a-b can be actuated by pressure applied against the ball when it is installed in the work string 410. One pusher 418b can open the valves 430 when the work string 410 is lowered into the bottom in the assembly 420, while the other pusher 418a may close the valves 430 when the work string 410 is operating at the wellhead in the assembly 420. The same may be true for opening and closing the flow devices 440 with pushers 418a-b, as described below. Thus, the pusher 418b is working, falling down, while the other pusher 418a is working, rising up. Other designs may be used and other types of pushers may also be used.

[0090] As an example, the pushers 418a-b can each be hydraulically actuated according to the standard industrial "B" pusher. When the switching ball (74) is discharged into the working string 410, the application of hydraulic pressure at the bottom of the working string 410 actuates the pushers 418a-b so that they act on the spring-loaded keys for switching valves 430 and the flow devices 440 open or close. Pushers 418a-b may be actuated together by the same ball 414 or individually actuated by balls 414 of various sizes, depending on the configuration.

[0091] As before, the assembly 420 has a production string 422 supported from the packer 16 in the casing 12. Along its length, the string 422 has isolation devices 429, valves 430, and flow devices 440. The isolation devices 429, which may be packers seal the annular space of the borehole 15 around the assembly 420 and divide the annular space 15 into different zones or sections 428A-C. Each section 428A-C has at least one of the valves 430 and at least one of the flow devices 440, both of which can selectively communicate with the through channel 425 of the column, with the annular space of the well 15, as described below. At its lower end, the assembly 420 has a lower socket 422 for engaging the switching ball 424 to close the shoe 420 during hydraulic fracturing, gravel packing or hydraulic fracturing with the installation of a gravel filter.

[0092] As shown, the selective valve 430 is located on the side of the mouth from the flow device 440 in each of the different sections 428A-C. Alternatively, a selective valve 430 may be located on the bottom side of the flow device 440 in each section 428A-C. In addition, this section 428A-C may have more than one valve 30 and / or flow device 440.

[0093] Selective valves 430 have one or more windows 432 that can be selectively opened and closed during operation. With this design, as in the others described above, each of the selective valves 430 can be opened to communicate its windows 432 with the surrounding annular space 15 by means of a pusher 418a on the work string 410. As before, the valves 430 can be sliding couplings having a movable locking element 434, such as an inner sleeve or insert, that insulates or opens windows 432 in the sliding sleeve housing.

[0094] Like valves 430, flow devices 440 also have one or more windows 442 that can be selectively opened and closed during operation. Each of the flow-through devices 440 also includes a shutter and a filter 446. The shutter in this design includes a first shut-off element 444 that selectively opens and closes the flow through the flow-through windows 442 and includes a second shut-off element 450, which is at least , prevents the flow of fluid from the through channel 425 through the filter 446.

[0095] This system 400 is a single-trip, multi-layer system, as described in previous embodiments. Briefly, the assembly 420 is launched into the well as part of a production string 422 or a string system located in the well, and the liner packer 16 is hydraulically installed. Processing is then performed for the various zones or sections 428A-B of the annular space of the well 15 by selectively opening the valves 430.

[0096] After treatment (eg, gravel packing or hydraulic fracturing) is completed, excess gravel or proppant is cleaned from assembly 420 and valves 430 are closed because they are mainly used for outlet windows for processing. In order to prepare the assembly 420 for operation, the flow devices 40 are opened in the assembly 420 from the production string 410 on the same flight in the wellbore by opening the first shut-off element 444 (for example, an internal sleeve) to open the flow-through windows 442. After opening flow devices 440 filter the fluid from the annular space of the borehole 15 into the through channel 425 of the column. At the same time, the second locking element 450 of the flow device is operative to prevent reverse flow. As described in more detail below, for example, a second locking element 450 of the flow device, which can use a single-pass or non-return valve, can prevent the loss of fluid in the formation when pulling the work string 410 from the assembly 420 and during production.

[0097] With the usual understanding of how assembly assembly 420 is used, the discussion now returns in more detail to how processing processes are performed. Initially, when descending into the well, all valves 430 and flow devices 440 on the assembly 420 are closed. After installing the liner packer 16 and closing the lower receptacle 450 with the switching ball 454, the operators install packers 429 along the assembly 420 with the appropriate procedures to create several isolated sections 428A-C at the bottom of the annular space of the well 15. After the packers 429 are installed, operators can begin with applying sequential preparation of each of the isolated sections 428A-C by selectively opening and then closing the selective valves 430 with pushers 418a-b on the work string 410.

[0098] As shown in FIG. 11A, for example, the selective valve 430 for the lower section 428A is open, but its accompanying flow device 440 remains closed. To open this bottom valve 430, the operators position the work string 410 next to the valve 430 and drop the switching ball (414) to the pushers 418a-b on the work string 410. Then the operators increase the pressure of the work string 410, and the pressure applied in the channel 415 of the work string against the mounted ball (414) and actuates the pushers 418a-b. Using an opening tool (e.g., 418b), operators open the valve 430 (for example, by shifting the inner sleeve 434 to the position-valve 430 is open). After the valve 430 opens, the operators reduce the applied pressure and release the return flow so that the installed ball (414) in the work string 410 can be reversed through the channel of the work string 415 to the surface.

[0099] For example, the flow device 440 may be a sliding sleeve having a movable locking element 444, such as an inner sleeve or insert that insulates or opens windows 442 in the sliding sleeve housing. The flow device 440 can be opened for communication of its windows 442 with the surrounding annular space 15 through the filter 446 using a pusher 418a on the working string 410. Thus, the flow device 440 in the closed position does not connect the through channel 425 of the column with the annular space 15 of the well through filters 446, but the flow device 440 in the open position allows the filtered fluid from the annular space 15 to pass through the filter 446 to the device 440 and into the through channel 425.

[00100] Operators now position the work string 410 at the mouth of the open valve 30, as shown in FIG. 11A. When controlling the work string 410 in the assembly 420, the work string 410 is in a position where the through channel in the assembly 425 is depressurized relative to the open windows 432 in the valve 430. In other words, the work string 410 in the section 428A to be processed does not engage with gaskets or sockets inside the through channel of the assembly 425, as in the previous embodiment.

[00101] Without sealing the casing 410 in the section of the prefabricated assembly 428A, the operators send the composition for processing the trunk area down the casing 410 to process the annular space of the well 15 for this section 428A. The fluid leaves the openings 412 in the workstring 410 and flows along the first flow path through the openings 432 of the valve 430 and into the formation around the annular space of the open hole section 15. To maintain pressure in the assembly 420 during operation, the system 400 may utilize existing annular technology space (if auxiliary packer 17 is not used or can be removed, or system 400 can use clean compression technology with auxiliary packer 17 in casing 12).

[00102] At the same time, when processing is performed, the shutter on the flow device 440 at least impedes the flow of fluid through the windows 442 and the filter 446 from the through channel 425 into the annular space of the well 15. Prevention of leakage from the filter 446 can be achieved either the first or second locking elements 444 and 450, or both. Preferably, when the first shut-off element 444 also prevents the fluid from flowing out of the annular space of the borehole 15 into the through channel 425, through a filter 446.

[00103] After the processing of the first section 428A is completed, the operators reverse at least some excess slurry from the work column 410 so that processing can begin with the next section 428B. Operators drop the switching ball (not shown) down the work string 70 again and increase the pressure in the work string 410 to actuate the pushers 418a-b with the ball 414 installed. Using the powered tools 418a-b, the operators close the open valve 30 for the bottom section 428A with a closing tool 418a. After the pressure drops, the workstring 410 rises to the valve 430 in the next section 428B. At this point, the operators raise the pressure on the installed switching ball 414 in the work string 410 again and open this valve 430 with a powered opening tool 418b. After lowering the applied pressure in the work string 410 and reversing the installed ball 414, the processing of this new section 428B is repeated as before.

[00104] Similar processes are repeated for all subsequent sections (ie, 428C) of the assembly 420. Once processing is completed for all sections 428A-C, all valves 430 and the flow device 440 on the assembly 420 are closed. Operators perform the flushing process. To do this, the work string 410 goes down to the shoe 420 of the assembly 420, and the operators pump the flushing fluid down the casing 12 to reverse any residual gravel, proppant or other composition to treat the near-barrel zone upward of the work string 410. Since all valves 430 closed, operators have no problems with return flow for flushing work.

[00105] When the flushing is completed, the operators open all the flow devices 440, so that their windows 442 communicate with the through channel 425 of the column for receiving production. The work string 410 is positioned in the direction of the lower shoe 426, and the operators throw the switching ball 414 again. Pressure is applied to the installed ball 414 to actuate the pushers 418a-b on the workstring 410, and the operators lift the workstring 410 and open the first shut-off elements 444 (for example, the inner sleeve) of the flow devices 440 at the top of the assembly 420 using an opening tool 418b .

[00106] As soon as the flow devices 440 open, fluid from the annular space 15 of the well may pass along the second flow path through filters 446, shut-off elements 450 and open windows 442. When the flow-through devices 440 open at the top of the assembly 420, the second shut-off elements 48 ( for example, unidirectional or non-return valves) of the flow devices 440 prevent loss of fluid from the through channel of the work column 425 to the annular space 15 during this process. As shown in FIG. 11B, when all the flow devices 440 are open, the work string 410 is removed from the assembly 420. At this point, the assembly 420 is ready to receive production through filters 446, shut-off elements 450, and open windows 442 through a second flow path.

[00107] As you can see, the operation of this system 400 can reduce the time and risks associated with the processing, because no service tool needs to be sealed in the assembly 420. In addition, the capture and operation time is reduced. Essentially, the work string 410 can be lowered during the installation run of the column, so no additional lowering is required. Flushing and opening / closing windows 432 and 442 in valves 430 and flow devices 440 will all be done on the same flight.

[00108] This example of a system 400 is described for an open hole, but the system 400 for a cased well will be the same, except that the isolation packers 429 may be different. Since the system 400 does not use falling balls in the assembly 420 to open the valve 430 or flow devices 440, the number of steps that can be deployed in the well is not limited to the required downsizing of the balls and sockets. In addition, no balls or sockets remain in the assembly 420 after processing processes, so the process does not require a separate milling operation, which can be time consuming and may encounter its own problems. In essence, the wellbore is ready to receive the tubing string after the process is complete.

[00109] As noted above, in conventional gravel packing systems, a sand slurry is introduced into the mouth of the annular space of the well filter and it circulates into the bottom of the well (ie, from heel to toe). The toe-to-heel system, as described, for example, in FIG. 2A-7 modifies this flow path and introduces a sand slurry into the annular space of the filter in the toe of the well and extends it to the wellhead. Additional details regarding this system are provided in United States Patent Application No. 12/913981, filed October 28, 2010. The toe-to-heel system of FIG. 2A-7 is designed so that any excess sand slurry in the work string can be placed in the bottom in a special annular space of the well. This is because the backward circulation of the excess slurry from the work string with the toe-to-heel system of FIG. 2A-7 is not practical. In particular, reverse circulation would require the application of pressure inside the filters and opposite the formation, and this additional pressure applied to the formation can lead to the formation of fluid loss in the formation or, worse, to hydraulic fracturing. Accordingly, the toe-to-heel system of FIG. 2A-7 is designed in such a way that any excess sand slurry in the work string can be emptied from the bottom into a special annular space of the well.

[00110] In order to enable reverse circulation, the systems of FIG. 8-11B, disclosed above, have an additional pressure supporting the integrity of the inner surfaces of the filters without the need for a separate pipe string or device, which must be lowered and actuated by measures in the well. Additional details regarding this system are provided in United States Patent Application No. 13/670125, filed November 6, 2012. The systems of FIG. 8-11B still provide an opportunity for the influx of formation fluids that can be produced by the well. In a broader sense, such pressure, supporting additional integrity of the inner surfaces of the filters, may be included in the toe-to-heel system, such as described above with reference to FIG. 11A-11B.

[00111] For this, the heel toe system 600 disclosed in FIG. 12A-12D equips each downhole filter 640 with shutoff elements 645 (e.g., non-return valves or the like). During use, the shutoff elements 645 on the filters 640 prevent the flow of fluid inside the filters 640 from flowing to the outside of the filters 640, but allow the flow of fluid from the outside of the filters 640 to enter the assembly 620. This allows operators to apply pressure within the assembly of the shank 620 with a filter after gravel packing in order to reverse the circulation and remove excess slurry from the work string 610 after completion of the gravel packing.

[00112] Returning to FIG. 12A, the system 600 comprises a packer 14 that is installed in the casing 12 above the borehole region from which production or injection will be made. Below the packer 14, the shank assembly 620 with the filter is spaced apart into one or more zones of interest. If there are several zones, packers 670 (or open or cased wells) are spaced to isolate one section of filter 602A-C from another. Packers 670 do not require shunts to go through them for multi-layer gravel packing, but they can be equipped in this way.

[00113] Assembly 620 and packers 670 descend into the bottom of the well in one run. This system 600 segments several separate, separated zones, so that several gravel packing processes as well as hydraulic fracturing can be performed. As shown herein, system 600 has separate gravel pack sections 602A-C, separated by packers 670, that act as spacers in an open hole to isolate one zone from another. One or more packers 670 may be used to isolate each of the gravel pack sections 602A-C from each other. Any suitable packers may be used, and they may include, for example, a hydraulic packer, hydrostatic packers, and swellable packers. Packers 670 provide zone isolation when installed in well 10 to stop the progress of processing in isolated zones.

[00114] Each section 602A-C may be similar to systems 200, 300, and 400, as described above. Each section 602A-C has a filter 640 and windows 650. Filters 640 include a shutoff element 645 (e.g., a one-way valve, non-return valves, or the like). Windows 650 of adjacent filters 640 may or may not include valves 652 or selective couplings.

[00115] This system 600 has a work string 610, which is located in the assembly 620 for processing (for example, gravel packing or hydraulic fracturing with the installation of a gravel filter) of the formation. As shown, the workstring 610 has external gaskets 612 located adjacent to the outlet windows 614. The discarded ball 414 can be installed in a remote socket of the workstring 610 to divert the fluid flow down the workstring 610 from the outlet windows 612 to the windows 650 in the assembly 620 for treating the surrounding formation. However, other configurations for the work string 610 may be used.

[00116] The production string 610 is deployed in the first section 602A and flushes by communicating the output windows of the column 612 with a check valve 626 on the column shoe 620 of the system 600. After flushing, packers 670 are installed to create several insulated sections at the bottom of the annular space of well 15. Packers 670 can be installed hydraulically, hydrostatically, using radio frequency tags, or pressure pulses.

[00117] When the packers 670 are installed, operators can start applying processing (ie, fracturing, gravel packing, fracturing with a gravel pack, etc.) sequentially to each of the isolated sections 602A-C. In particular, the column 610 may be selectively positioned in any one of the various sections 602A-C along the system 600. In a selective position, the outlet windows of the column 612 with their gaskets 614 are isolated together with flow windows 650 for gravel packing and / or hydraulic fracturing with the installation of gravel an annular space filter 15 around this gravel pack section 602A-C. Then, the inner working column 610 can be moved so that the outlet windows 612 are isolated from these flow ports 650 so that reverse circulation can be performed to remove excess slurry from the working column 610 before moving it to the next gravel pack section 602A-C. A similar process can be repeated up the wellbore for each section of gravel pack 602A-C, separated by packers 670.

[00118] As shown in FIG. 12B, in particular, after washing, the outlet windows of the column 612 with their gaskets 614 are isolated together with the consumable windows 650 for gravel packing and / or hydraulic fracturing with the installation of a gravel filter of the first section of gravel packing 602A. If the flow ports 650 include a valve, then the valve may be opened, for example, by opening it with a cam clutch. The slurry is transferred downstream of the workstring 610, exits the outlet windows 612 and passes through the windows of sections 650 to flow into the isolated annular space of this first section 602A. Gravel from the slurry is packed in the annulus from toe to heel, as described in this document, and the drilling fluid from the slurry passes through a filter 640 into the annular space between the liner 630 and the production string 610. The drilling fluid can then flow to the wellhead past the packer 14 to casing 12 and to the surface.

[00119] As shown, windows 650 may have selective valves or couplings 652 that can be opened by pushers 616 on work string 610, although these components may not be necessary in each embodiment. Typically, the pusher 616 may be a “B” pusher to bias the valve 652 relative to the windows 650. Thus, opening this valve 652 includes engaging the pusher 616 in the corresponding profile of the valve 652 and move the valve 652 to the work string 610 to the open position, so that the through channel of the assembly 625 communicates with the annular space of the well 15 through the currently open windows 650.

[00120] As shown in FIG. 12B, the gaskets 614 on the work string 610 can engage and seal against the inner seats 654, surfaces, gaskets, or the like, near the windows 650 in the assembly 620 on both sides of them, from the mouth and bottom. Gaskets 614 may use elastomeric or other types of seals located on inner workstring 610, and jacks 654 may be polished sockets or surfaces within assembly 620 to engage gaskets 614. Although the configuration shown in this configuration may be reversed, with gaskets on the inside of the assembly 620 and with sockets on the workstring 610. In addition, some embodiments may not have gaskets and sockets at all, but instead may rely on opened e and closing valve 652 on the windows 650 for controlling fluid flow.

[00121] After the working column 610 is installed, the composition for processing the trunk zone flows down through the through channel of the working column 610 to the windows 650 in the first zone 602A. The composition for processing the near-barrel zone flows through the outlet windows 612 in the working string 610 and through the windows 650 to the surrounding annular space of the well 15, which allows the composition for processing the near-barrel zone to interact with the adjacent zone of the formation. For example, during hydraulic fracturing, a composition can be pumped into the annular space to treat the near-barrel zone with proppant or gravel in suspension.

[00122] The toe-to-heel gravel pack in system 600 allows the drilling fluid to pass through filter 640 and dehydrate the slurry intended for gravel packing of sections 602A-C of the annular space of the well 15 during the gravel pack or hydraulic fracturing process with the gravel pack installed. In contrast to the construction of FIG. 9, no separate bypass or tube is required for the drilling fluid during the process. Instead, drilling mud R can flow through a filter 640 and pass through a non-return valve 645 on the filter 640 to the through channel 625 of the assembly 620. When the barrel treatment composition flows from the work string 610 installed on the windows 650 into the annular space of the well 15 , the downhole filter 640 filters the drilling fluid from the annular space 15, and the drilling fluid may flow at the mouth of the assembly 620 from the engagement of the production string 610 in the assembly 620. From this moment, the drilling fluid may flow to the surface.

[00123] In the end, sand will fall out when the first section 602A is sufficiently gravel packed. As then shown in FIG. 12C, the workstring 610 can be controlled to move to an intermediate position so that the outlet ports 612 communicate with the inner surface of the filter shank assembly 620. Once processing is complete for a given area 602A, operators can control the workstring 610 to engage the follower 616 in the valve 652 to close the windows 650. For example, the follower 616 can engage another suitable profile on the valve 652 to move the valve 652 and close the windows 650 .

[00124] At this point, the workstring 610 can be moved in the assembly 620 to an intermediate position, which allows the excess slurry to be removed from the workstring 610 before moving the workstring 610 to the new zone 602B. As will be appreciated, any excess slurry in the workstring 610 can flow into the assembly 620, while the workstring 610 is controlled, and any gravel, proppant, sand or the like, in the slurry can cause adhesion problems with the workman column 610, polluting valves, etc.

[00125] Thus, in an intermediate position, the outlet ports 612 on the work string 610 open for the through channel 625 in the assembly 620. The reverse circulation can be pumped down into the bottom of the well 12 and into the annular space between the work string 610 and the assembly 620. This purifies the excess suspension, which is transferred back up to the working column 610.

[00126] After the reverse circulation is completed, the work string 610 can be moved in the assembly 620 to another zone 602B to perform processing. Operators repeat this process up the assembly 620 to process all sections 602A-C. Once processing is complete, system 600 may not need a cleaning flight.

[00127] With the system 600 noted above, gravel packing can be achieved where downhole filters 640 can be pressurized on the inside. This allows the system 600 to operate under reverse circulation, which exerts pressure within the assembly 620. Being able to reverse circulation, this method allows for single-layer gravel packing by the toe-to-heel method and sequentially reverses the excess slurry. System 600 also allows multiple gravel packings to be performed at various points in the wellbore, reversing after each individual gravel pack process. The work string 610 inside the assembly 620 may be located at each injection point in the assembly 620, starting from the lowest point, for example, and can deliver the gravel pack slurry to the annular space 15, circulating in the manner of the toe to the heel. Once the sand has been sufficiently pumped, the work string 610 is reset so that the pressure applied to the casing 12 and inside the assembly 620 causes any excess slurry to circulate back up the work string 610. After the suspension is removed, the work string 610 rises to to the next download site, and the steps are repeated.

[00128] The foregoing description of preferred and other embodiments is not intended to limit or reduce the scope or applicability of the concepts of the invention proposed by the applicants. It should be understood, to the advantage of the present disclosure, that the elements of one embodiment may be combined or replaced with the components of the other embodiments disclosed herein. References were made in this document for the use of prefabricated gravel pack units in wells, such as open-hole wells. Typically, these wells may have any orientation, vertical, horizontal or deviated. For example, a horizontal well may refer to any deviated portion of the well forming an angle of 50 degrees or more and even more than 90 degrees with respect to the vertical.

[00129] In exchange for disclosing the inventive concepts contained herein, applicants desire all patent rights granted in accordance with the attached claims. Thus, it is intended that the appended claims include all modifications and changes to the fullest extent that they fall within the scope of the appended claims or their equivalents.

Claims (33)

1. A device for processing a formation for a well, comprising:
a housing located in the well and forming a through channel;
one or more sections located on the housing, each of one or more sections containing:
an insulation element located on the housing and isolating the annular space of the well around the section from other sections,
a window located on the housing and providing fluid communication between the through channel and the annular space of the well,
a filter located on the housing and communicating with the annular space of the well,
a shutter located on the housing and at least preventing fluid from flowing from the through channel to the filter; and
the working column forming the outlet and controlled in the housing with respect to each section, and the working column in the first operating mode delivers the composition for processing the near-barrel zone from the exit to the section of the annular space of the well through the window, the working column in the second operating mode receives reverse circulation from the through channel to the exit. 2. The device according to p. 1, in which the working column in the first mode of operation delivers the suspension as a composition for processing the near-barrel zone, the suspension has a carrier fluid and has at least one proppant and gravel. 3. The device according to p. 1, in which the window contains a flow valve, selectively acting between open and closed positions, providing and preventing the communication of fluid between the through channel and the annular space of the well. 4. The device according to claim 3, in which the flow valve comprises a sleeve configured to move in the through channel between (a) a closed position that prevents the fluid from communicating through the window, and (b) an open position that allows fluid to communicate through the window. 5. The device according to claim 3, in which the working column is configured to at least open the flow valves of one or more sections. 6. The device according to p. 3, in which the working column contains a power tool made with the possibility of opening and closing the flow valves of one or more sections in the same flight in the through channel. 7. The device according to claim 6, in which the drive tool is configured to operate hydraulically. 8. The device according to claim 6, in which the drive tool is configured to at least open the shutters of one or more sections in the same flight in the through channel. 9. The device according to claim 1, in which the working column contains a first gasket near the outlet, each of one or more sections containing second gaskets located in the through channel adjacent to the window, the second gaskets mesh with the first gaskets and isolate the fluid message exit with a window. 10. The device according to p. 1, in which the working column, which receives reverse circulation from the through channel to the outlet, in the second mode of operation transfers an excess of the composition for processing the trunk zone to the mouth. 11. The device according to claim 1, in which the insulation element contains at least one swellable packer, a hydraulically installed packer, a hydrostatically installed packer and a mechanically installed packer. 12. The device according to claim 1, in which the shutter is configured to selectively act between: (a) a closed position that prevents fluid from communicating between the through channel and the filter, and (b) an open position that provides fluid communication between the through channel and the filter . 13. The device according to p. 12, in which the shutter comprises a sleeve configured to move in the through channel between: (a) a closed position that prevents fluid from communicating through at least one flow window in the housing, at least one flow window in communicating with the filter, and (b) an open position providing fluid communication through at least one flow window. 14. The device according to p. 12, in which the shutter contains a unidirectional valve located in fluid communication between the filter and the through channel, and the unidirectional valve in the open position provides fluid communication from the filter to the through channel and in the closed position prevents the fluid from communicating from the through channel to the filter. 15. The device according to p. 14, in which the unidirectional valve comprises:
a casing located on the housing and a coupling filter with at least one flow window in the housing; and
a ball valve positioned movably in the housing, the ball valve providing fluid communication from the filter to the at least one flow window and preventing fluid from communicating from the at least one flow window to the filter. 16. The device according to p. 1, in which the window for this of one or more sections is located in the direction of the toe, and the filter for this section is located towards the heel, and the window delivers a suspension as a composition for processing the trunk zone and gravel packing of the annular space this section from the toe to the heel, and the filter filters the drilling fluid from the suspension into the through channel of the body. 17. The device according to p. 1, in which the window for this of one or more sections is located towards the heel, and the filter for this section is located towards the toe, and the window delivers a suspension as a composition for processing the trunk zone and gravel packing in the annular space of this section is from the heel to the toe, and the filter filters the drilling fluid from the suspension, and the section has a bypass that delivers the drilling fluid to the window of the mouth of the through channel body. 18. The device according to p. 17, in which the bypass contains a tube connected at one end to the window of the through channel in the bottom hole, and on the other to the window of the through channel from the mouth side. 19. The device according to claim 1, in which the working column is controlled in the same flight to open the gates after processing all of one or more sections. 20. A method of treating a formation for a well in which:
isolating the annular space of the borehole around the prefabricated unit into a plurality of isolated zones, the prefabricated unit in each isolated area having a first window and a filter connecting the through channel of the prefabricated unit with the annular space of the well;
place the working column in the through channel of the assembly unit;
process the annular space of the well in at least one of the isolated zones by:
the flow of the composition for processing the near-stem zone down the working column into at least one isolated zone through the first window, and
obtaining a drilling fluid composition for processing the near-barrel zone from at least one isolated zone into the through channel of the assembly through the filter; and
remove the excess composition for processing the near-stem zone from the working column by:
reverse circulation down through the through channel of the assembly to the working column, and
at least preventing reverse circulation in the through channel from communication with the annular space through the filter. 21. The method according to p. 20, containing the initial location of the assembly in a casing having perforations, in an expanded string of pipes having grooves, or in an open hole. 22. The method according to p. 21, in which the isolation of the bottom of the annular space of the borehole around the prefabricated unit in the isolated zones contains isolation elements that engage on the prefabricated unit against the casing wall, the wall of the expanded pipe string or the wall of the open hole. 23. The method according to p. 20, in which the flow of the composition for processing the trunk region down the working column to at least one isolated zone through the first window comprises selectively opening the first window in the assembly in an isolated zone from the working column. 24. The method according to p. 23, in which the selective opening of the first window in the assembly in an isolated area from the working column comprises moving the coupling in the assembly at a distance from the first hole from the working column. 25. The method of claim 23, further comprising selectively closing the first window in an isolated area from the work string after processing. 26. The method according to p. 20, in which the flow of the composition for processing the trunk zone down the through channel into the isolated zone through the first window comprises sealing the outlet of the working column in fluid communication with the first hole. 27. The method according to p. 20, in which the processing of at least one isolated zone comprises:
the passage of the suspension, as a composition for processing the trunk area from the first window, located towards the toe,
gravel packing of the annular space of at least one isolated zone from the toe to the heel, and
mud filtration into the through channel of the assembly through the filter located towards the heel. 28. The method according to p. 20, in which the processing of at least one isolated zone comprises:
the passage of the suspension as a composition for processing the near-trunk zone from the first window located towards the heel,
gravel packing of the annular space of at least one isolated zone from the heel to the toe,
filtering the drilling fluid into the through channel of the assembly through a filter located towards the toe, and
drilling mud bypass into the through channel through the first window of the assembly from the mouth. 29. The method of claim 20, wherein at least preventing fluid from flowing through the channel to the annular space of the well through the filter comprises selectively preventing fluid from flowing through the channel to the filter through a second window of the assembly. 30. The method according to p. 29, in which the selective prevention of fluid from the through channel to the filter through the second window of the assembly includes the operation of a non-return valve located in communication between the filter and the second window. 31. The method according to p. 29, in which additionally carry out the preparation of an isolated zone for operation by:
selective opening of the second window of the prefabricated unit in an isolated area from the working column; and
permitting fluid communication from the annular space of the well to the through channel through a filter and a second window in an isolated zone. 32. The method according to p. 31, in which additionally filtering the borehole products from the annular space of the well of the isolated zone into the through channel of the assembly through the filter and the second window. 33. The method according to p. 31, in which the selective opening of the second window of the assembly in an isolated area from the working column comprises moving the coupling in the assembly at a distance from the second window from the working column.

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