GB2515624A

GB2515624A - Degradable component system and methodology

Info

Publication number: GB2515624A
Application number: GB1407350.6A
Authority: GB
Inventors: Michael D Howard
Original assignee: Schlumberger Holdings Ltd
Current assignee: Schlumberger Holdings Ltd
Priority date: 2013-04-26
Filing date: 2014-04-25
Publication date: 2014-12-31
Also published as: GB201407350D0; US20140318780A1

Abstract

A system and method of use thereof, for use in a well comprising a well string having a well tool, the well tool 28 comprising a primary flow passage 44 and a port 46 positioned to direct a flow of fluid for performance of a task downhole, the well tool further comprising a degradable material 30 positioned in the port to temporarily block flow of fluid through the port until the degradable material, which may be formed as a plug 36 or a degradable ring 56, is degraded over time via exposure to a degradation fluid downhole. Also claimed is a system which may further comprise a well tool actuable between a plurality of positions via shifting of a shiftable component 38 (fig 1), the well tool further comprising a degradable material positioned to temporarily prevent shifting of the shiftable component until the degradable material is sufficiently degraded via exposure to a degradation fluid present at a downhole location

Description

DEGRADABLE COMPONENT SYSTEM AND METHODOLOGY

BACKGROUND

[0001] 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 welibore is drilled, various forms of well completion components may be installed to control and enhance the efficiency of producing the various fluids from the reservoir, In many applications, hydraulically actuatable tools are employed in the well completion for carrying out specific tasks downhole. To protect against premature actuation, burst disks are sometimes positioned in the hydraulic control line to prevent premature buildup of pressure at a location that could actuate the tool.

SUMMARY

[0002] In general, a system and methodology are provided for protecting against premature actuation of a tool, such as a downhole well tool, The system and methodology utilize a degradable material positioned along, for example, a hydraulic actuation passage and/or between shiftable components of the tool. In some applications, the tool may comprise a primary flow passage and a hydraulic actuation passage separate from the primary flow passage. Hydraulic actuation of the to6l is temporarily blocked by placing a degradable material in the hydraulic actuation passage, The degradable material dissolves or otherwise degrades over time via exposure to a degradation fluid.

Tn other applications, the degradable material may be positioned to temporarily block movement of a shiftable component of the tool.

[0003] 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.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] 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: [0005] Figure lisa schematic illustration of an example of a well system deployed in a wellbore and comprising a plurality of tools which utilize degradable material to protect against premature actuation, according to an embodiment of the

disclosure;

[0006] Figure 2 is a cross-sectional view of an example of a well tool, e.g. a hydrostatic setting module, having a degradable material temporarily blocking flow along a hydraulic actuation passage, according to an embodiment of the disclosure; [0007] Figure 3 is a cross-sectional view of a portion of the well tool illustrated in Figure 2, according to an embodiment of the disclosure; [0008] Figure 4 is a cross-sectional view of another example of a well tool having a degradable material temporarily blocking flow along a hydraulic actuafion passage,

according to an embodiment of the disclosure;

[0009] Figure 5 is a cross-sectional view of an example of a component formed of a degradable material, according to an embodiment of the disclosure; [0010] Figure 6 is another cross-sectional view of the degradable component illustrated in Figure 5, according to an embodiment of the disclosure; [0011] Figure 7 is a front view of another example of a tool incorporating degradable material to block premature actuation of the tool, according to an embodiment

of the disclosure; and

[0012] FigureS is a cross-sectional view of the tool illustrated in Figure 7,

according to an embodiment of the disclosure.

DETAILED DES CRIPTION

[0013] 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.

[0014] The disclosure herein generally involves a system and methodology for protecting against premature actuation of a tool, In well applications, for example, the technique protects against premature actuation of a packer, a hydrostatic setting module, a chemical injection mandrel, and/or other tools operated downhole in a wellbore. The system and methodology utilize a degradable material that may be positioned along a hydraulic actuation passage and/or between shiftable components of the tool. Tn various well applications, for example, the tool may comprise a well tubular having a primary flow passage and a hydraulic actuation passage separate from the primary flow passage.

Hydraulic actuation of the tool or a corresponding tool is temporarily blocked by placing a degradable material in the hydraulic actuation passage. For example, the degradable material may be used to temporarily plug and seal setting ports, flow ports, injection ports or other ports in various downhole devices. The degradable material dissolves or otherwise degrades over time via exposure to a degradation fluid, e.g. a downhole well fluid such as brine, oil or natural gas. Tn other applications, the degradable material may be positioned to temporarily block movement of a shiftable component of the tool.

[0015] Tn some embodiments, the degradable material may be used in combination with or to replace rupture discs in hydrostatic set tools, such as hydrostatic setting modules and hydrostatic set packers. In such applications, the degradable material serves as a non-pressure activated setting port or pressure insensitive trigger. In conventional hydrostatic systems, a rupture disc is used in a closed system and pressure is increased to rupture the disc prior to actuation of the packer or hydrostatic setting module. However, the use of degradable materials as described herein to plug setting ports, for example, enables hydrostatically operated tools to be activated in open systems rather than conventional closed systems. For example, embodiments utilizing degradable materials may enable hydraulic actuation in perforated, open hole wells and other open system applications.

[0016] Tn certain embodiments, the use of degradable materials to plug setting ports enables hydrostatic set packers, hydrostatic setting modules, and other hydrostatically operated tools to be actuated without sensitivity to pressure, Consequently, some of these embodiments may provide a closed system which can be pressure tested to a full working pressure to confirm system integrity prior to hydrostatically actuating the tool, e.g prior to setting a packer. By way of example, the degradable material may be formed as a degradable port plug fitted and sealed within the corresponding setting port. Sometimes a rupture disc may be placed in series with the degradable material to, for example, protect the degradable material from fluids until ruptured. The rupture disc provides another degree of control over the system, [0017] Degradable materials/components may be used to control actuation in a variety of applications, For example, degradable materials may be used in setting ports of hydrostatic set packers to enable zonal isolation in open systems, such as open hole completions having sand screens and inflow control devices. Such systems may be used to replace conventional swellable packers. Tn other applications, the degradable material may be formed as a degradable port plug for use in the hydraulic injection passage of a chemical injection mandrel or other injection mandrels. The degradable material also may be used in many applications to replace rupture discs. Such placement addresses many of the issues associated with rupture discs, including issues related to debris from the rupture disc, pressure testing at less than full working pressure, premature bursting of the rupture disc, debris from the rupture disc captured in system filters, and other potentially detrimental aspects of rupture disc usage.

[0018] Referring generally to Figure 1, an embodiment of a well system 20 is illustrated as deployed in a wellbore 22. The well system 20 comprises a well string 24 extending down into wellbore 22 from a surface location 26. The well string 24 comprises at least one hydraulic actuation tool 28 for which hydraulic actuation and/or flow of hydraulic actuation fluid is controlled by a degradable material 30, By way of example, hydraulic actuation tool 28 may comprise a hydrostatic selling module or hydrostatic set packer 32 which is actuated via hydraulic actuating fluid supplied through a hydraulic actuation passage 34, The degradable materia' 30 may be in the form of a degradable material plug 36 positioned in hydraulic actuation passage 34, e.g. in a setting port through which the hydraulic actuation fluid flows to actuate the module/packer 32, [0019] The hydraulic actuation tool 28 also may comprise a variety of other types of tools. For example, tool 28 may comprise a variety of shiftable tools having a shiftable component 38 which may be shifted, via hydraulic actuation fluid, between a plurality of operational positions. In certain embodiments, the shiftable component 38 may comprise a piston used to actuate the tool 28 from a first operational position to a second operational position. The piston may be in the form of a cylindrical piston, a sliding sleeve, or other suitable members which may be selectively shifted upon application of sufficient pressure. In this example, the degradable material 30 is positioned to temporarily, physically block and prevent shifting of the shiftable component 38 until the degradable material 30 is sufficiently degraded, e.g. dissolved, via exposure to a degradation fluid. The degradation fluid may be a downhole fluid naturally occurring downhole or supplied to the downhole location. The hydrostatic actuation fluid may be a fluid naturally occurring downhole or a fluid directed downhole via a control line or other flow passage.

[0020] The examples illustrated are for purposes of explanation and should not be construed as limiting the applications of degradable material 30 in controlling actuation of tools. In some applications, for example, the degradable material 30 may be used in combination with check valves, e.g. downstream of check valves, to further control flow of actuating fluid, In other applications, the degradable material may be used to temporarily plug gas lift valves and/or water flood regulators to facilitate annulus and tubing pressure testing during completion installation. The degradable material also may be used in certain applications with drill stem test (DST) tools.

[0021] Another embodiment involves using degradable material 30 for actuation components, such as mechanical trigger mechanisms in various tools. For example, the degradable material 30 may be formed as a degradable ring which can be placed at a suitable location in a packer to prevent an actuation piston from stroking before a predetermined delay, In fact, the degradable material 30 may be used in a variety of tools and applications to provide a mechanical delay, In packer applications, the degradable material 30 may be used with a hydraulically set packer to provide a sufficient delay for facilitating testing, e,g, pressure testing of an entire completion multiple times against a downhole plug, without setting of the packer.

[0022] Tn other embodiments, the degradable material 30 may be formed as plugs and used in setting ports/hydraulic actuation passages to facilitate subsequent actuation of pressure operated downhole tools without intervention and without applying pressure at the surface. The degradable material 30 also may be used to temporarily isolate normally open valves, thus enabling pressure testing during deployment and automatic reversion to the normal operating condition when the degradable material has degraded over a given period of time, [0023] The degradable material 30 also may enable construction of adjustable degradable plugs for use in cased hole completion applications utilizing hydrostatic setting mechanisms and hydraulically set packers, In these embodiments, the hydraulically actuated assembly is coupled into a completion string and run to depth until a tubing hanger is landed in a tubing head spool or wellhead, At this stage, the system, e.g. tubing, casing, tubing hanger, and other system components, may be pressure tested to the ifill working pressure without activating the packer setting mechanism. After a predetermined period of time, the adjustable degradable plug degrades to allow communication between the weilbore and an internal atmospheric chamber of the hydraulic setting module or hydrostatic packer, thus providing the force to set the device.

The mass/size of degradable material 30 in the degradable plug may be changed to adjust the time period for degradation.

[0024] In open hole or open system applications, a hydraulic setting module may be provided with an adjustable degradable port plug formed of degradable material 30.

In this application, the hydraulic setting module may be connected to hydraulic set open hole packers. The hydrostatic setting devices are then run to depth and placed in position to isolate zones in the open hole wellbore, After a predetermined period of time, the degradable material is degraded by degradation fluids ocated downhole, This allows communication between the wellbore and an internal atmospheric chamber of the hydrostatic setting devices, thus allowing downhole fluids to enter the chamber and to provide the force for setting the packers and isolating the well zones.

[0025] Additionally, the degradable material 30 may be formed as a mechanical locking mechanism used with hydrostatic setting modules/packers to mechanically prevent actuation of the device prior to degradation of material 30, In some applications, such a mechanical locking mechanism may be used in combination with a port plug formed of the degradable material 30. In many applications, the use of degradable material 30 provides a more controllable and reliable system relative to conventional swellable packers which can sometimes lose their seal due to the loss of a catalyst, eg.

due to the loss of oil in the event of a change in well fluid properties during water cut or other events, [0026] The degradable material 30 also may be used in a variety of injection applications. For example, a degradable port plug formed of degradable material 30 may be inserted into a chemical injection flow passage downstream of check valves in a chemical injection mandrel, Depending on the construction of the chemical injection mandrel, the degradable port plug may be inserted through an external port along an exterior of the mandrel body which is adjacent to and in line with the injection port. A sealing member, such as a metal-to-metal sealing external cap screw, can be used to seal the external port. The plug of degradable material 30 also facilitates internal testing of the injection mandrel bore to full working pressure. If check valves are used, the check valves of the injection mandrel may be pressure tested through an external port which also may be used to pressure test an upstream side of the plug of degradable material 30.

[0027] Another application of degradaNe material 30 comprises using the degradable material 30 in forming a spacer ring or similar member which is then position to prevent energized pistons from traveling prematurely, The degradable material effectively renders the tool inactive until the degradable material degrades and allows the components to move relative to each other, For example, degradable rings or segments may be strategically placed within hydrostatic/hydraulic packers to prevent the packer setting piston from shifting until a sufficient period of time has past to allow degradation fluids to degrade the material 30. Tn some applications, the degradable component may be used in place of collets or other conventional components and may be preinstalled or installed in the field. Additionally, the degradable material 30 may be used to form a loadbearing component, e.g. a loadbearing support ring, segment, or sleeve, to mechanically lock a tool in an non-actuated condition.

[0028] The degradable material 30 may be formed from a variety of materials depending on the environment and available fluids for degrading the material 30. For example, degradable materia' 30 may be designed to dissolve or otherwise degrade in hydrostatic fluids, e.g. oil or gas, completion brines, or other fluids which caused the degradable material 30 to dissolve or otherwise break down, The degradable material 30 continues to break down into small pieces/particles until the mechanical integrity of the

S

material is lost and the downhole tool may be activated. Examples of degradable materials 30 comprise highly reactive metals such as calcium, magnesium or alloys thereof The degradable material 30 also may comprise materials that dissolve in acidic or basic fluids, e.g. aluminum, polymers or specially formulated plastics. Additionally, degradable materials such as metals and metal alloys of the type used to create dissolvable balls and other dissolvable objects also may be used to form degradable material 30, [0029] Referring generally to Figure 2, an embodiment of hydraulic actuation tool 28 is illustrated. By way of example, the illustrated tool 28 may comprise a hydraulic setting module 40. However, the illustrated hydraulic actuation tool 28 also may comprise a hydrostatically set packer, e.g. packer 32, or may be coupled with the packer to provide control over the hydraulic actuation. In this example, tool 28 comprises a housing 42 providing a primary flow passage 44 and a hydraulic actuation passage 46 separate from the primary flow passage 44, For example, the hydraulic actuation passage 46 may be routed through or along housing 42 extema to primary flow passage 44. The hydraulic actuation passage 46 may comprise a port 48 through which actuation fluid may be flowed to selectively actuate the packer 32 or other hydraulically actuated tool 28.

[0030] Depending on the application, tool 28 may comprise a variety of other features. Examples of such features comprise a hydraulic coupling 50 by which the housing 42 and hydraulic actuation passage 46 may be coupled with a hydraulically actuatable packer 32 or other actuatable device. Additional features may comprise a pressure intensifier 52 having pistons and flow passages of selected surface areas to provide a desired change in actuation pressure applied to actuate a downhole tool, such as packer 32.

[0031] As further illustrated in Figure 3, degradable material 30 may be formed as plug 36 positioned in port 48 of hydraulic actuation passage 46. The degradable plug 36 may be customized to match a specific tool. For example, a mass and/or size of the degradable plug 36 can be adjusted to vary a degradation period over which the degradable material 30 dissolves or otherwise degrades to allow flow of actuation fluid along hydraulic actuation passage 46. In the example illustrated, the degradable plug 36 further comprises an external seal 54 which forms a seal between the degradable material and the surrounding wall of hydraulic actuation passage 46/port 48. By way of example, the external seal 54 may comprise a layer of sealing material, such as rubber or other suitable elastomeric material, In some embodiments, a burst disc 56 may be positioned along hydraulic actuation passage 46 upstream or downstream of degradable material 30 depending on the parameters of a given application.

[0032] Referring generally to Figure 4, another example of hydraulic actuation tool 28 is illustrated. In this example, the degradable material 30 is constructed as a degradable ring 56 disposed in housing 42 to temporarily b'ock flow of actuation fluid along hydraulic actuation passage or passages 46, As further illustrated in FigureS, the ring 56 of degradable material 30 may be positioned in a hollowed out ring section 58 of housing 42 and may be used to temporarily block flow of actuation fluid through a plurality of ports 48, OO33] The degradable ring 56 also may comprise a seal 60 disposed along the degradable material 30, as ifirther illustrated in Figure 6. The seal 60 may be formed of rubber or another suitable elastomeric material able to form a seal between the degradable material 30 and the surrounding walls of ring section 58. Tn some applications, the seal 60 may comprise a plurality of seals disposed along an exterior and an interior of the degradable material 30. Additionally, the degradable material 30 may be fully encased in the material of seal 60, e.g. encased in molded rubber covering both the interior and exterior of the degradable ring 56.

[0034] In the embodiment illustrated, the degradable ring 56 is secured within ring section 58 of housing 42 via an end cap 62 and a spacer or spacers 64, Tn some applications, the end cap 62 is a non-sealing member disposed within ring section 58. By way of example, ring section 58 may be formed from a steel material and degradable material 30 may be formed from a dissolvable alloy or other suitable material that degrades over a predetermined period oftime, The size, e.g. height, of the degradable ring 56 may be adjusted to provide a corresponding adjustment of the period of time over which the ring degrades to enable flow of actuation fluid through ports 48.

100351 Referring generally to Figures 7 and 8, another embodiment of hydraulic actuation tool 28 is illustrated. In this embodiment, the hydraulic actuation tool 28 comprises an injection mandrel 66, such as a chemical injection mandrel. The injection mandrel 66 comprises housing 42 which forms primary flow passage 44. The primary flow passage is separated from hydraulic actuation passage 46 (a chemical injection passage in this application) which may be routed externafly of primary flow passage 44.

In this type of application, the actuation passage 46 may comprise a crossover passage 68 by which fluids, e.g. injection chemicals, are introduced into primary flow passage 44.

[0036] Depending on the specifics of a given application, the injection mandrel 66 may comprise a variety of additional components. By way of example, various components may be positioned along passage 46 and may include a pair of check valves separated by a dual insert adapter 72. The various components also may comprise an injection line coupler 74 and an adapter plug 76 coupled with housing 42 via a seal ring 78. The degradable material 30 is positioned along the passage 46 to temporarily block flow of fluid along passage 46. The use of degradable material 30 enables pressure testing along passage 46 and primary flow passage 44 in both directions to a full working pressure, [0037] In some applications, the degradable material 30 may be positioned in crossover passage 68. Access to crossover passage 68 may be provided by an external opening 80 which may be plugged by a suitable plug 82, e.g. a cap screw, after insertion of degradable material 30 into crossover passage 68. In this example, the degradable material 30 is formed as degradable plug 36 and the external seal 54 is positioned between the degradable material 30 and the surrounding wall of fluid passage 46. The degradable material 30 may be fully encased in the material of external seal 54, e.g. encased in molded rubber. Additionally, the size, e.g. mass/length, of the degradable plug 36 may be adjusted to provide a corresponding adjustment in the period of time over which the plug 36 degrades to enable flow of chemicals or other fluids through passage 46. Tn a chemical injection application, pressure testing may be performed after installation of mandrel 66 downhole and then the degradable material 30 of plug 36 is allowed to gradually degrade until normal operation of the injection mandrel 66 is available.

[0038] The system 20, e.g. well system, may be used in a variety of applications, including numerous well production applications, treatment applications, and non-well related tubing applications, Depending on the specifics of a given tubing string, well application, and environment, the construction of the overall system 20, well string 24, and hydraulic actuation tools 28 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 single or multiple tools 28.

[0039] Depending on the application, the tool 28 may be constructed in several configurations. For example, the hydraulic actuation tools 28 may be constructed to control flow to a variety of cooperating, actuatable tools or the hydraulic actuation tools 28 may incorporate shiftable or otherwise actuatable components. The degradable material may be used to control flow along a hydraulic actuation fluid passage and/or to physically delay, e.g. temporarily block, transition of movable elements, The degradable material may be incorporated into a variety of hydraulic selling modules, hydraulically actuated packers, valves, sliding sleeves, piston actuated tools, and/or other tools used downhole or in other applications. The degradable material may be used to temporarily delay actuation to provide time for pressure testing or other types of tool/system testing prior to normal operation.

[0040] 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.