Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore is drilled, various forms of well completion components, including production tubing, may be installed in the well. In certain applications, inflow control devices are employed to create flow restrictions through the production tubing. The fluid flow in the annulus between the production tubing (or screens) and the wellbore also may be restricted. As a result, the production inflow to the production tubing tends to be more distributed over the length of the production string instead of being concentrated in highly permeable zones or at the top of the production string.
Additionally, gravel packing may be used as a sand control method. A gravel packing operation is performed by mixing gravel with a carrier fluid which is then pumped down the wellbore annulus. The gravel is left in the wellbore annulus to protect the screens, while the carrier fluid flows inwardly through the screens and is routed to the surface. Sometimes, bypass channels are provided to facilitate flow in cases when the wellbore becomes blocked during placement of gravel via the gravel packing operation.
In general, a system and methodology are provided for facilitating a well operation. At least one dehydration tube is located along an exterior of filter media of a plurality of screen assemblies deployed in a wellbore. The at least one dehydration tube is fluidly coupled to a base pipe of at least one of the screen assemblies via a base pipe opening. Fluid flow along the at least one dehydration tube and/or into the base pipe is controlled with a flow control mechanism. Additionally, an inflow of fluid from an exterior to an interior of select screen assemblies is separately controlled with an inflow control device associated with each select screen assembly.
However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The disclosure herein generally involves a system and methodology for facilitating a well operation, such as a sand control operation employing a gravel pack downhole in a wellbore. In an embodiment, at least one screen assembly and often a plurality of screen assemblies is deployed downhole and at least one dehydration tube is located along an exterior of filter media associated with the screen assemblies. The at least one dehydration tube has an outlet which is in fluid communication with a base pipe of at least one of the screen assemblies via a base pipe opening. During and after a gravel packing operation, for example, fluid flow along the at least one dehydration tube is controlled with a flow control mechanism. Additionally, an inflow of fluid from an exterior to an interior of select screen assemblies is separately controlled with an inflow control device associated with each select screen assembly.
In some embodiments, a sand control system is provided with the screen assembly or a plurality of screen assemblies which are connected together to form a tubing or pipe string that is disposed in the wellbore of a well. The screen assemblies may include inflow control devices (ICDs) to restrict flow from the exterior of the well screen assemblies into the interior of the well screen assemblies. Attached to the outside of the screen assemblies is a dehydration tube that may extend along the length of the screen assemblies. The dehydration tube includes openings that are sized to filter out particles larger than a predetermined size. The openings may be perforations or slits that are sized to filter gravel, e.g. sand, used in gravel packing a well. Gravel packing is used to place gravel in an annulus surrounding the screen assemblies between the exterior of the screen assemblies and the wellbore wall.
A sand control method may be performed by mixing gravel with a carrier fluid to form a gravel slurry. Gravel slurry is pumped downhole and into the wellbore annulus surrounding the screen assemblies. Gravel from the gravel slurry is deposited in this wellbore annulus, and the carrier fluid is removed from the annulus by pulling at least a portion of the carrier fluid into the interior of the screen assemblies and back to the well surface. The dehydration tube filters the gravel slurry and provides a dehydration flow path for the carrier fluid from the exterior of the filter media associated with the screen assemblies to an interior of the screen assemblies.
Referring generally to
As further illustrated in
In some embodiments, a single screen assembly 22 may be employed, but the illustrated embodiment comprises a plurality of screen assemblies 22 and each screen assembly 22 has filter media 34 to filter particulates out of fluid entering from the exterior of the screen assembly 22 to the interior 30 of the screen assembly 22. The filter media 34 may be, for example, a wire wrap media, a mesh screen media, a perforated pipe, or another suitable filter media. If the filter media 34 is a wire wrap, the wire wrap may comprise a direct wire wrap or a jacket. The filter media 34 also may be in the form of a tube or other enclosure having permeable portions for filtration and non-permeable portions overlaying the base pipe 32. The permeable portions of the filter media 34 may be wire wrap, mesh, or other suitable types of filter media. In this type of embodiment, the inflow control devices 38 may be positioned beneath the overlying non-permeable portion of the filter media 34. In the example illustrated, the screen assemblies 22 are coupled together end-to-end with base pipe connectors 40. The base pipe connectors 40 are located at the ends of each screen assembly 22. Depending on the embodiment, the base pipe connectors 40 may comprise conventional connectors used in connecting sections of base pipe 32 or other suitable connectors.
The dehydration tube 24 includes openings 42 which may be in the form of perforations, slots, or other suitable openings. The openings 42 extend through the outer wall of the dehydration tube 24 and are sized to filter particles so as to allow carrier fluid of the gravel slurry to enter into the interior of the dehydration tube 24. In the example illustrated, the dehydration tube 24 extends along the length of the plurality of screen assemblies 22. However, the dehydration tube 24 may be constructed to extend over portions of that length, or the dehydration tube 24 may be constructed as a plurality of separate dehydration tubes.
In some embodiments, the dehydration tube 24 forms a dehydration tube flow path 44 which extends continuously along the screen assemblies 22. The dehydration tube 24 is disposed in the annulus 28 which may be located in either an open hole wellbore or cased hole wellbore. Gravel slurry carrier fluid flows from the annulus 28, into the dehydration tube 24, and along the dehydration tube flow path 44. In this example, the dehydration tube flow path 44 is routed along the exterior of the plurality of screen assemblies 22. As used herein, placement of the dehydration tube 24 and the dehydration flow path along the exterior of the screen assemblies refers to placement of the dehydration tube 24 and the dehydration flow path along the exterior of filter media 34 of the screen assemblies 22. In some embodiments, the dehydration tube or tubes 24 are located externally of the filter media 34 and within a surrounding shroud. Depending on the application, individual screen assemblies or the plurality of screen assemblies 22 may have other components placed inside and/or outside of the dehydration tube(s) 24.
In the embodiment illustrated, the sand control system 20 further comprises a leak-off screen assembly 46 attached to an end of one of the screen assemblies 22, e.g. to an end of the lower or distally located screen assembly 22 or to another suitable screen assembly 22. The leak-off screen assembly 46 may be in the form of a shorter screen assembly relative to screen assemblies 22. The leak-off screen assembly 46 further comprises openings 48, e.g. perforations, which provide relatively unrestricted flow into the interior 30 of base pipe 32. Carrier fluid flowing along the flow path 44 of dehydration tube 24 flows toward the leak-off assembly 46 and exits the dehydration tube 24 through a discharge or outlet 50, e.g. outlet slots or perforations. The filtered carrier fluid flows from discharge 50 and into the base pipe 32 through openings 48 of leak-off screen assembly 46. In the embodiment illustrated, the lower or distal end of the dehydration tube 24 may be closed to block gravel from entering the dehydration tube 24. The openings of discharge 50 may be located adjacent the openings 48 of leak-off screen assembly 46. For example, the openings of discharge 50 may overlie the openings 48. The carrier fluid entering the base pipe 32 through openings 48 is circulated along interior 30 to a surface of the well. In some applications, the leak-off screen assembly 46 also may comprise a suitable inflow control device 38 which may be in the form of a conventional inflow control device, a sliding sleeve, a valve mechanism, or another suitable device for controlling the inflow of fluid, e.g. to selectively block the flow of fluid through openings 48 during a production operation. In some applications, a sliding sleeve, valve mechanism, or other flow blocking device also may be positioned along the dehydration tube 24 so as to block flow through the openings of discharge 50 and to thus isolate the leak-off screen assembly 46.
In another example, the outlet 50 of the dehydration tube 24 is connected directly into the wall of base pipe 32 at, for example, a location below the distal screen assembly 22 to provide an opening and flow path into the interior 30 of base pipe 32. In this type of embodiment, the leak-off screen assembly 46 may be omitted. The carrier fluid simply flows into the dehydration tube 24, moves along the interior of the tube 24, and then flows directly into the interior 30 of the base pipe 32 via the direct connection. A flow control device, such as a sliding sleeve or valve, may be used to selectively block flow into the base pipe 32. Depending on the application, an individual dehydration tube 24 may be constructed to provide flow to interior 30 at each section of base pipe 32 of each screen assembly 22; or the dehydration tube 24 may be constructed to provide flow to interior 30 at selected sections of base pipe 32 of selected screen assemblies 22 such that some screen assemblies 22 are skipped with respect to inflowing fluid from the dehydration tube 24. Similarly, a plurality of dehydration tubes 24 may be used to direct flow to the interior 30 at each screen assembly 22 or at certain, selected screen assemblies 22.
In the embodiment of
Each valve 52 cooperates with a leak-off port or base pipe opening 54 and serves as a flow control mechanism 56 disposed to control flow into base pipe 32 through opening 54. However, valves 52 are just one type of flow control mechanism 56, and mechanism 56 may comprise sliding sleeves, reactive materials, and other devices able to selectively block flow, as discussed in greater detail below. In some applications, the base pipe opening 54 may have a flow area of approximately 300 to 3000 mm2. Similarly, some applications may employ a dehydration tube 24 having a cross-sectional flow area of approximately 300 to 3000 mm2. However, other embodiments of the base pipe opening 54 and dehydration tube 24 may have flow areas of other sizes to accommodate a given application. As with the previously described embodiment, carrier fluid is filtered as it flows into an interior of the dehydration tube 24 and the filtered carrier fluid is delivered to the interior 30 of base pipe 32 through flow control mechanisms 56. For example, each valve 52 may be transitioned between an open position allowing flow into base pipe 32 and a partially or fully closed position which restricts flow into interior 30 of base pipe 32. The valves 52 or other flow control mechanisms 56 may be selectively closed and/or opened by, for example, a shifting tool 58 attached at the end of a tubing 60, e.g. a wash pipe. For example, the shifting tool 58 may be used to close the flow control mechanisms 56 when the wash pipe 60 is retrieved out of the wellbore 26 after a gravel packing operation has been completed in the annulus 28. However, other devices, e.g. coiled tubing, wireline, or other suitable devices, and other intervention techniques may be employed to partially or fully close the flow control mechanisms 56. Additionally, some devices and techniques may be designed to close or begin closing at least some of the flow control mechanisms 56 during the gravel packing operation. In some applications, the flow control mechanism 56 may be positioned at intermediate positions between the closed and open positions. In the example illustrated in
In some applications, the tubing/wash pipe 60 provides a flow path for carrier fluid flowing into base pipe 32. For example, the tubing 60 allows carrier fluid to flow from the base pipe openings 54 into a wash pipe annulus 62 within base pipe 32. The carrier fluid then flows along the exterior of wash pipe 60 until reaching an end of the wash pipe 60 at which point the carrier fluid flows into the interior of the wash pipe 60. The interior of the wash pipe 60 provides a flow path for the carrier fluid and directs the carrier fluid to the surface of the well.
Referring generally to
Referring generally to
In some applications, individual jumper tubes 72 comprise flow control mechanism 56 in the form of a jumper valve 76. The jumper valve 76 has an open position which allows fluid to flow through the jumper tube 72 from one dehydration tube 24 to the next. The jumper valve 76 also has a closed position in which fluid is fully or partially restricted from flowing through the jumper tube 72 from one dehydration tube 24 to the next. In an operational example, the sand control system 20 is run downhole with the jumper valves 76 in the open position. This allows fluid to flow through the sequential dehydration tubes 24. During an/or after performing a gravel pack, the jumper valve or valves 76 can then be shifted to a closed position. In the closed position, fluid flow between sequential dehydration tubes 24 and thus between sequential screen assemblies 22 is restricted. Thus, the jumper valves 76 help prevent cross flow of production fluids between the different screen assemblies 22 by restricting flow through the dehydration tubes 24 following, for example, the gravel packing operation.
In some applications, the jumper valve 76 may be formed with a reactive material 78 disposed along the interior of the jumper tube 72 (see also
Crossflow between screen assemblies 22 also may be limited by separately coupling the plurality of dehydration tubes 24 with the base pipe 32 at corresponding base pipe openings 54. (e.g. see
In an operational example, sand control system 20 is run in hole from a surface of the well. The sand control system 20 may comprise a gravel packer (not shown) connected to the base pipe 32, thus allowing the sand control system 20 to be fixed in the wellbore 26. A gravel slurry formed of carrier fluid and gravel is then pumped from the surface of the well and down into the wellbore 26. The gravel may comprise sand or other types of proppant and may be pumped through a suitable service tool or tubing. As with conventional gravel packing systems, the gravel slurry flows below the gravel packer and through a crossover to a section of tubing having a gravel flow port. The gravel slurry flows through the gravel flow port and into the annulus 28 along the exterior of the screen assemblies 22. The dehydration tube(s) 24 filter out the gravel and allow the carrier fluid to flow into the interior of the dehydration tube(s) 24 through dehydration tube openings 42. From the interior of the dehydration tubes 24, the carrier fluid is routed into interior 30 of base pipe 32 via base pipe openings 54 which may include leak-off screen opening 48. The carrier fluid freely flows through base pipe openings 54, because the flow control mechanisms 56 are in an open position. A portion of the gravel slurry also may be filtered by filter media 34 before passing into interior 30 through inflow control devices 38.
Carrier fluid flowing into the interior 30 of screen assemblies 22 may then be moved, e.g. pumped, towards the surface of the well. As a result, the gravel slurry is dehydrated and the gravel forms a gravel pack in the annulus 28 adjacent the screen assemblies 22. Because the flow of carrier fluid through the inflow control devices 38 is somewhat restricted, the dehydration tubes 24 help distribute the inflow via dehydration tube openings 42 and base pipe openings 54. The combined flow area of the inflow control devices 38 and the base pipe openings 54 (receiving flow from the dehydration tube or tubes 24) provides a higher flow rate into the interior 30 of the screen assemblies 22 during the gravel pack operation. Consequently, excessive fluid loss to the formation is avoided and chances are reduced with respect to reaching a fracture pressure limit of the formation.
The leak-off screen assembly 46 also may be used to provide an increased flow area into the interior 30 of screen assemblies 22. Other types of openings may further be provided along the screen assemblies 22 and such openings may be sized to provide a desired additional flow area into the interior 30. Upon completion of a gravel packing operation, the flow control mechanisms 56 may be closed to restrict flow into the base pipe 32, e.g. to prevent flow through base pipe openings 54 and through leak-off screen assembly opening 48. In some applications, the flow control mechanisms 56 may comprise the reactive material 78, e.g. swellable material, located in jumper tubes 72 or at other positions along the dehydration tube or tubes 24 to restrict flow after completion of the gravel packing operation.
Following the gravel packing operation, a production operation may be commenced. During the production operation, hydrocarbon fluid from the surrounding reservoir flows into the wellbore 26. The screen assemblies 22 filter sand and other particulates from the hydrocarbon fluid as it moves into interior 30 of the screen assemblies 22 through the inflow control devices 38. The inflow control devices 38 provided a controlled restriction of flow into the interior 30 of base pipe 32. The restriction provided by the inflow control devices 38 helps distribute the flow rate into the different screen assemblies 22 in a controlled manner. The hydrocarbon fluid is then routed upwardly through the interior of the base pipe 32 to a surface of the well.
The flow control mechanisms 56 control the flow from dehydration tube or tubes 24 to the interior 30 of base pipe 32 and they may be constructed in a variety of forms and arranged in a variety of configurations. For example, the flow control mechanisms 56 may comprise sliding sleeves (see
As illustrated in
Referring generally to
In some embodiments, filtration devices are deployed along the dehydration tube 24. As illustrated in
In some applications, the filter plug 92 may comprise a filter plug housing 94 having a fastening mechanism 96, e.g. a threaded region, as illustrated in
As illustrated in
Referring generally to
The sand control system 20 may be used in a variety of applications, including numerous types of well production applications. Depending on the specifics of a given well application and environment, the construction of the overall system 20, screen assemblies 22, dehydration tubes 24, shunt tubes 64, and filtering techniques/media may vary. Additionally, the system may be designed for use in many types of wells, including vertical wells and deviated, e.g. horizontal, wells. The wells may be drilled in a variety of formations with single or multiple production zones and with many types of gravel packs.
Depending on the application, many types of devices for controlling flow also may be employed in the overall system 20. For example, a variety of inflow control devices 38 may be constructed and positioned to control flow from the annulus 28 to the interior 30 of base pipe 32. Additionally, many types of flow control mechanisms 56 may be used to control flow of carrier fluid along the dehydration tube or tubes 24 and/or to control flow from the dehydration tube(s) 24 into the interior 30 of base pipe 32. A variety of valves, sliding sleeves, reactive materials, e.g. swellable rubbers and other swellable materials, degradable materials, and other devices may be used alone or in combination as flow control mechanisms 56.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
The present document is based on and claims priority to U.S. Provisional Application Ser. No.: 61/858,405 filed Jul. 25, 2013, and to U.S. Provisional Application Ser. No.: 61/985,289 filed Apr. 28, 2014, both of which are incorporated herein by reference.
Number | Date | Country | |
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61858405 | Jul 2013 | US | |
61985289 | Apr 2014 | US |