Patent Application
20120285702
In a variety of well related applications, downhole tools are actuated to perform desired functions. For example, packers, valves, and other downhole tools may be selectively actuated at specific times during a downhole procedure and/or at specific locations within a wellbore. Several types of mechanisms have been employed to enable actuation of the tool at the desired time and/or location.
For example, rupture discs and other shear mechanisms have been employed to control actuation of one or more downhole tools. However, such mechanisms often limit the number of tools that can be operated in a predetermined sequence. Additionally, these types of mechanisms can be difficult to use in applications and environments in which the maximum pressures available are limited. Intelligent triggering devices also have been used to control the selective actuation of downhole tools based on signals delivered to the intelligent triggering devices. In various environments and applications, however, some of these types of devices can be difficult to use or unreliable. Explosive materials also have been employed to open flow paths downhole. However, components with explosive materials can be difficult to ship or transport to a well site due, at least in part, to governmental regulations on handling and transporting such materials.
Embodiments of the claimed system or methodology may comprise the use of a downhole tool in a well string. The downhole tool may be actuated via the controlled flow of a fluid, e.g. a hydraulic fluid, under pressure to the downhole tool through a port. Flow of the pressurized fluid through the port is controlled by a barrier member which may be opened by a plunger working in cooperation with the barrier member. Movement of the plunger is controlled by selectively increasing the pressure acting on the plunger through, for example, actuation of a gas generating device or other suitable device.
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 drawings only illustrate various implementations described herein and are not meant to limit the scope of various technologies described herein. The drawings are as follows:
In the following description, numerous details are set forth to provide an understanding of some illustrative embodiments of the present invention. However, it will be understood by those skilled in the art that various embodiments of the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
As described herein, a tool actuation system may be utilized with a variety of downhole tools to provide dependable actuation of one or more downhole tools in a variety of well related applications. By way of example, the tool actuation system may be used in cooperation with different types of downhole valves, packers, and other downhole tools which are actuated by a fluid, e.g. a hydraulic fluid, under pressure. In many applications, such downhole tools may be actuated by the pressure of well fluid. The tool actuation system is designed to selectively control the flow of high pressure well fluid to the desired downhole tool or tools.
According to one embodiment, the tool actuation system comprises a barrier member, e.g. a pressure membrane/rupture disc or valve, which blocks flow of pressurized actuating fluid to a downhole tool. A plunger is movably mounted within a housing and is oriented to transition the barrier member. For example, the plunger may be positioned to open a valve or to impact a rupture disc in a manner which fractures or weakens the rupture disc. The plunger is driven by expansion of a suitable material within an expansion chamber, and the suitable expansion material may comprise a gas generating energetic material. However, the plunger and the expansion material are uniquely designed so the system falls within the US Department of Transportation (DOT) “Not Regulated” class. The design enables shipping of the product without labeling the product as explosive and without subjecting the product to the shipping restrictions required with respect to explosive devices.
Expansion of the selected material within the expansion chamber is initiated by an initiator device which may be designed to receive signals from an uphole location, e.g. a surface location. A variety of techniques and types of systems may be employed to communicate signals downhole to the initiator device to selectively initiate opening of the port and flow of pressurized actuating fluid to the downhole tool or tools. By way of example, the signals may be transmitted via cable-to-surface systems, electromagnetic telemetry systems, acoustic telemetry systems, wireline systems, coiled tubing with wireline systems, coiled tubing with fiber optic systems, drilling and measurement systems (e.g. mud pulse or electromagnetic telemetry systems), or other suitable telemetry systems. Additionally, the tool actuation system may comprise a plurality of trigger systems, e.g. a plurality of plungers, which cooperate with corresponding barrier members to enable repeated closing and opening of the port for repeated downhole tool actuations.
Referring in general to
In the example illustrated, well system 20 comprises a downhole equipment assembly 26 which incorporates downhole tool 24. The downhole equipment assembly 26 may comprise a bottom hole assembly, a well completion assembly, or other types of downhole equipment selected according to the specific well operation being conducted. The downhole equipment assembly 26 may be delivered downhole along a wellbore 28 from a surface location 30 via a suitable conveyance 32. Depending on the well application, conveyance 32 may comprise production tubing, coiled tubing, cable, wireline, slick line, or other suitable conveyances.
The downhole tool actuation system 22 comprises a downhole portion 34 which may be referred to as the trigger system. The downhole portion 34 is selectively operated to control flow of actuating fluid to downhole tool 24 based on signals received from a control system 36. In some embodiments, downhole portion 34 operates to open a port 38 which allows high pressure well fluid to flow into downhole tool 24 from an annulus 40 surrounding the downhole tool 24. The high pressure well fluid serves to actuate downhole tool 24 by shifting the downhole tool to a desired operational configuration. However, port 38 may be positioned to control flow through hydraulic control lines, through an interior of conveyance 32, or through other suitable features to selectively enable flow of actuating fluid to downhole tool 24.
In the example illustrated, control system 36 is positioned at a surface location 30, however the control system also may be positioned at remote locations or at both remote and well site locations. In some applications, the control system 36 may be manually operated while in other applications the control system 36 is partially or fully automated to act upon the occurrence of specific parameters detected downhole or at other locations. If the control system 36 is automated, the control may be conducted from a downhole location in certain applications. In the example illustrated, however, control system 36 is coupled to downhole portion 34 by a suitable communication line 42 which may be a hard wired or wireless communication line. Depending on the well application, a variety of telemetry systems may be employed for conveying signals between control system 36 and downhole portion 34. By way of example, signals/commands may be transmitted via acoustic telemetry (e.g. mud pulse telemetry), electromagnetic telemetry, seismic telemetry (e.g. air guns, detonation sources, or impact sources positioned at the surface), radio frequency telemetry (e.g. RF tag telemetry systems), electrically conductive path systems from surface or subsurface (e.g. wireline or control line type systems), or combinations of the telemetry systems.
Depending on the specific well application and on the type of telemetry system employed to convey signals downhole, the downhole portion 34 may have various configurations. As illustrated in greater detail in
Plunger member 46 is moved by an expansion device 50 which may be in the form of a gas generating device. In the example illustrated, expansion device 50 is a gas generating device having an expansion chamber 52 in which gases are rapidly expanded to drive the plunger member 46 which, in turn, opens port 38. The expansion device 50 comprises an expansion material 54 disposed in expansion chamber 52, and the expansion material 54 may be in the form of a gas generating energetic material, e.g. a pyrotechnic material. The expansion material 54 rapidly expands upon initiation of the desired reaction by an initiator device 56 which receives command signals from control system 36 via communication line 42. As described above, the communication line 42 may be wired or wireless and it may carry a variety of signals depending on the type of telemetry system employed in the downhole tool actuation system 22.
However, the expansion device 50 is designed as a DOT “Not Regulated” class device to facilitate handling and transport of the device. Specifically, expansion device 50 is designed (and the expansion material 54 and/or plunger member 46 are selected) such that the expansion device 50 and overall tool system meet the testing criteria required for such devices. In this example, the testing criteria include assessing the expansion material 54 and/or the component containing the expansion material 54, e.g. expansion chamber 52, to ensure the component/materials are not ruptured or fragmented. The criteria further comprise ensuring the surface temperature in the vicinity of the expansion device 50 containing the expansion material 54 does not exceed 100° C. and ensuring the device provides little or no smoke generation. Additionally, the criteria require that the audible report from initiation of the expansion material does not exceed 150 dB when measured with an ANSI type 1 sound level meter placed not more than 1 meter away or does not exceed 140 dB when measured with an ANSI type 2 sound level meter placed not more than 1 meter away from the expansion material 54. Furthermore, the criteria require that no mechanical movement of more than 1 meter occurs in any direction as result of initiation of the expansion material 54, e.g. movement of plunger member 46. The structure of plunger member 46 and expansion chamber 52, the amount and type of expansion material 54, and the overall arrangement of the expansion device 50 and downhole tool 24, as described and illustrated herein, are designed within these criteria.
Accordingly, use of gas generating energetic material 54 to push the plunger member 46 facilitates the handling, transport, and implementation of the actuation system 22. By utilizing the gas generating energetic material 54 in the manner described, the overall actuation system 22 also avoids generation of fragments and/or release of hot gases. The amount of gas generating energetic material 54 and the design of plunger member 46 is selected to enable classification of the system and components as Not Regulated materials, as described above. This allows the expansion device 50 and other components of the actuation system to be shipped by standard commercial carriers. Consequently, the handling, transport, and implementation of such devices are substantially improved and simplified.
Referring generally to
The pressure sensor 58 works in cooperation with a battery 60 and an electronics module 62. The battery 60 is configured to supply electrical energy to electronics module 62 which, in turn, is designed to interpret the series of pressure pulses detected by pressure sensor 58. If a predetermined series of pressure pulses is detected by electronics module 62, the electronics module outputs an activation signal via appropriate communication lines 64, e.g. conductors, to initiate the expansion, e.g. gas generation, of expansion material 54 in expansion device 50. By way of example, the communication lines 64 may deliver an appropriate current, spark, chemical, or other signal to initiate the rapid expansion within expansion chamber 52. It should be noted that battery 60 may be replaced with other electric energy supplies, such as capacitors or electric supply lines routed downhole. Additionally, the electronics module 62 may comprise a variety of electronics modules, including processor-based modules. An example of one type of battery and electronics module which can be employed in the illustrated embodiment is described in U.S. Pat. No. 7,510,001.
Rapid expansion of expansion material 54 drives plunger member 46 along an interior of housing 48. By way of example, housing 48 may have a cylindrical interior 66 which serves as a cylinder along which the plunger member 46 slides to transition barrier member 44. In the embodiment illustrated, barrier member 44 comprises a valve 68 coupled to plunger member 46 by a coupling mechanism 70. As plunger member 46 is forced along interior 66, the coupling mechanism 70 transitions valve 68 from a closed position to an open position which allows the flow of hydraulic actuating fluid through port 38. Valve 68 may comprise a variety of valve types, including sliding sleeve valves and ball valves. As with the previously described embodiments, the expansion device 50, along with expansion material 54/plunger member 46, is designed as a DOT Not Regulated class device to facilitate handling and transport.
Referring generally to
In the example illustrated in
The specific configuration of the downhole tool actuation system 22 and its downhole portion 34 may be adjusted according to the parameters of a given well application and/or environment. The type of expansion material 54 may be selected according to the temperatures, pressures, environmental conditions, and/or system conditions related to the well operation being conducted. Also, the configuration of the plunger member, initiator device, electronics module, housing, barrier member, control system, communication/telemetry system, all may be adjusted or interchanged according to the needs of a given application.
Additionally, other mechanisms may be combined with, used in cooperation with, or employed as an alternative to the mechanisms described above for selectively transitioning the barrier member 44 to an open flow condition. In some embodiments, the barrier member may initially be weakened or combined with a weakening material, e.g. a chemical, designed to degrade the barrier member. For example, the pressure membrane may be selectively exposed to corrosive or reactive materials which deconstruct the membrane. Thus, the plunger member 46 may be used in cooperation with a variety of chemicals or other features designed to weaken or otherwise alter the pressure membrane or other type of barrier member 44 to facilitate opening of the flow port.
Although only a few embodiments of the present invention 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 invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.
