BACKGROUND
This disclosure relates to the field of well pressure control apparatus, known as blowout preventers (BOPs). More specifically, this disclosure relates to techniques for operating or actuating BOPs when the need for such action becomes apparent.
BOPs for oil or gas wells are used to prevent potentially catastrophic events known as blowouts, where high pressures and uncontrolled flow of fluid from a subsurface reservoir can blow tubing (e.g., drill pipe and well casing), tools and drilling fluid out of a wellbore drilled through such reservoir. Blowouts present a serious safety hazard to drilling crews, the drilling rig and the environment, and can be extremely costly. FIG. 1A shows a conventional BOP system 10 deployed underwater on a wellhead at the sea floor. FIG. 1B is an enlarged view of the BOP system 10 to illustrate certain components. Actuation of the BOP system 10 is controlled from a control panel (not shown separately) disposed at the sea surface and in signal communication with a controller 12. The controller 12 may be linked to the BOP system 10 through multiplex (MUX) communication cables 14. The BOP system 10 is provided with two subsea control pods, conventionally designated as blue 16 and yellow 18 control pods, and configured to actuate respective hydraulic accumulators 20 to close rams in the BOP system 10 when required.
In the event of an incident requiring actuation of the BOP system 10, an operator will press a button on the control panel (not shown) to cause the controller 12 to send a signal to operate either the yellow 16 or blue 18 control pod to actuate the respective hydraulic function and thereby supply hydraulic pressure to the BOP to actuate it. Since the BOP actuation system is hydraulically based, only one triggering signal can ultimately actuate the BOP rams or other BOP function (e.g., annular BOP, gate valves, etc.). For example, if the operator presses the button triggering the blue pod 18 and it fails to actuate, the operator must then operate a switch on the control panel to trigger the yellow pod 16. Nonetheless, only one hydraulic supply from one pod at a time (either blue or yellow) can actuate any part of the BOP, otherwise the hydraulic components are subject to jamming or malfunction. If both the blue 18 and yellow 16 pods fail to actuate, the operator must then use a backup actuating device (e.g., an acoustic signal system or physical actuation using a remotely operated vehicle (ROV) in the water). Independently initiating these BOP actuation devices can take considerable time, which may result in a catastrophic event in an emergency where rapid BOP actuation is critical. For example, when the Dynamic Position system on the rig fails, leading to the vessel drifting off position above the oil and gas well.
A need remains for improved techniques to rapidly and efficiently actuate BOPs, particularly when deployed underwater.
SUMMARY
One aspect of the present disclosure is a blowout preventer actuation system including a frame configured for underwater disposal. A kinetic blowout preventer is mounted on the frame and configured with an electrically operated initiator. At least one hydraulically actuated blowout preventer is also mounted on the frame. An interface module is disposed on the frame and configured for signal communication with the electrically operated initiator on the kinetic blowout preventer. The interface module is configured to generate an actuation signal to actuate the initiator upon detection of the at least one of an electrical signal, an acoustic signal, and a hydraulic signal.
A method for actuating a blowout preventer according to another aspect of this disclosure includes: disposing a kinetic blowout preventer on a frame configured for underwater disposal, the blowout preventer configured with an electrically operated initiator. disposing at least one hydraulically actuated blowout preventer on the frame; disposing an interface module on the frame, the module configured for signal communication with the electrically operated initiator on the kinetic blowout preventer; disposing the frame underwater; and generating an actuation signal to actuate the initiator upon detection of the at least one of an electrical signal, an acoustic signal, and a hydraulic signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows schematically a blowout preventer (BOP) system deployed underwater from a floating drilling platform.
FIG. 1B shows an enlarged detail view of the BOP system shown in FIG. 1A to identify control pods, control lines and respective accumulators.
FIG. 2 shows an example embodiment of a pyrotechnic charge actuated BOP.
FIG. 3A shows a BOP system deployed underwater including a kinetic BOP and a hydraulically operated BOP according to this disclosure.
FIG. 3B shows a more detailed view of certain components of the kinetic BOP shown in FIG. 3A.
FIG. 4 shows a BOP system deployed underwater including a kinetic BOP and a hydraulically operated BOP according to this disclosure.
DETAILED DESCRIPTION
Illustrative embodiments of a well pressure control apparatus are set forth in this disclosure. In the interest of clarity, not all features of any actual implementation are described. In the development of any such actual implementation, some implementation-specific features may need to be provided to obtain certain design-specific objectives, which may vary from one implementation to another. It will be appreciated that development of such an actual implementation, while possibly complex and time-consuming, would nevertheless be a routine undertaking for persons of ordinary skill in the art having the benefit of this disclosure. The disclosed embodiments are not to be limited to the precise arrangements and configurations shown in the figures and as described herein, in which like reference numerals may identify like elements. Also, the figures are not necessarily drawn to scale, and certain features may be shown exaggerated in scale or in generalized or schematic form, in the interest of clarity and conciseness.
Pyrotechnic based BOPs which address certain shortcoming of hydraulically actuated BOPs include those such as described in U.S. Pat. No. 11,028,664, issued to the present assignee and entirely incorporated herein by reference. FIG. 2 shows a sectioned view of a pyrotechnic based (hereinafter referred to herein as “kinetic”) BOP 30 according to an example embodiment of the present disclosure. The kinetic BOP 30 comprises a main body or housing 32 having a through bore 34. The kinetic BOP 30 also has a passage 36 that is arranged transversely to the through bore 34. A shearing device 38 with a cutting edge is located in the passage 36 on one side of the through bore 34.
A charge 40 which may be in the form of a pyrotechnic chemical propellant is located between the shearing device 38 and an end cap 42 disposed at one longitudinal end of the passage 36. In some embodiments, the charge 40 may be a deflagrating charge. In some embodiments, the charge 40 may be an explosive charge. The charge 40 when actuated produces pressure to propel the shearing device 38 along the passage 36 and across the through bore 34, closing off a wellbore (to which the main body 32 is coupled) as described in U.S. Pat. No. 11,028,664. In some embodiments, the charge 40 may be actuated by an initiator 44. For example, the initiator 44 may be a detonator or a blasting cap. FIG. 2 shows an initiator 44 in the form of a blasting cap. Actuating the charge 40 includes actuating the initiator 44 in response to a control signal. For example, the initiator 44 may be actuated in response to a hydraulic signal or an electrical signal as will be further explained below. Some kinetic BOP 30 embodiments may be configured with more than one initiator (not shown).
FIG. 3A shows an example embodiment of a BOP stack according to this disclosure. A kinetic BOP 30 may be incorporated into a BOP stack 50 deployed underwater on the sea floor F. The BOP stack 50 is coupled at one end to a riser 52 suspended from a floating platform 54 such as a ship at the sea surface as is known to be used in marine oilfield operations. In addition to the kinetic BOP 30, the BOP stack 50 may also comprise one or more conventional, hydraulically actuated BOPs 56 of any type known in the art. Other embodiments may be implemented without hydraulically actuated BOPs, or may be implemented with a single, or multiple kinetic BOPs such as shown at 30.
FIG. 3B shows an enlarged view of the end cap 42 (See FIG. 2) of the kinetic BOP 30 mounted in the stack 50. The initiator 44 may be disposed in the end cap 42 and may comprise a pair of electrical leads 58 to receive an electrical signal for actuation, in the present example embodiment one positive (+) lead and one negative (−) electrical lead. Upon application of an electrical actuation signal to the electrical leads 58, the initiator 44 produces a localized ignition that in turn actuates the charge 40. The actuated charge 40 propels the shearing device (38 in FIG. 2) across the through bore (34 in FIG. 2) as described with reference to FIG. 2. Such electrical signal may be provided to the electrical leads 58 by a cable 60. Once again referring to FIG. 3A, the cable 60 may be linked to an interface module 62 disposed on the BOP stack 50. The interface module 62 is further described below.
A multiplex (MUX) cable 64 of types known in the art may extend along the riser 52 to provide a signal and data transfer channel between the floating platform 54 and the BOP stack 50. The MUX cable 64 may also be used to provide electrical power to the BOP stack 50 and to the interface module 62 from a power supply (not shown) on the floating platform 54. In some embodiments, the interface module 62 and/or the BOP stack 50 may be provided with one or more batteries (e.g., as described with respect to FIG. 4) disposed at any convenient location on or about the BOP stack 50 to provide local backup electrical power as may be needed. As described above, in the event it becomes necessary to actuate the kinetic BOP 30 to close off the through bore (34 in FIG. 2), an operator on the floating platform 54 can press the button on the control panel (in communication with the controller 12), which causes the controller 12 to send an electrical signal to the interface module 62 along the MUX cable 64. The interface module 62 in response sends an electrical signal to the initiator 44 via the cable 60 and the kinetic BOP 30 is actuated. In some embodiments, the BOP stack 50 may be implemented with a local controller 12′ to provide the control functions described herein. For example, in some embodiments, the interface module 62 may be configured with a controller 12′, as shown in FIG. 3A. With such embodiments, an operator on the floating platform 54 can remotely provide activation signals to the controller 12′ via the control panel in communication with the controller.
In embodiments using hydraulically actuated BOPs 56, such as the example embodiment shown in FIG. 3A, the BOP stack 50 may be provided with conventional valves, hoses, and related hardware to direct pressurized hydraulic fluid from accumulators 66 to the BOP rams (not shown separately for clarity) as is known in the art. In some embodiments, accumulators may also be located on the floating platform 54 (not shown). With such configurations, hydraulic fluid for the BOPs 56 can either be directed from the surface-based accumulators and/or subsea accumulators 66. When an operator uses the control panel to actuate the surface-based and/or subsea accumulators 66 using the blue or yellow control pods (as described above at 18 and 16 with reference to FIG. 1B), a pressure sensor/transducer 68 coupled into the hydraulic lines 70 feeding the fluid to the BOP 56 rams detects pressure in the lines resulting from such operation and sends a corresponding signal to the interface module 62 indicative of ram actuation pressure being present in the hydraulic lines. The interface module 62 detects such pressure signal and may correspondingly send an electrical actuation signal to the initiator (44 in FIG. 3B) using the cable 60, and the kinetic BOP 30 is thereby actuated. In this way, the kinetic BOP 30 may be simultaneously actuated when any of the conventional BOPs are actuated while using only a single, hydraulic control signal from the floating platform 54.
In some embodiments, a fluid conduit 72 may extend between the ship 54 and the BOP stack 50 to provide a supply of hydraulic fluid to the BOP stack 50. Some embodiments of a BOP stack according to this disclosure may be implemented with a hydraulic fluid communication system, applying conventional fluid flow and/or pressure encoders/decoders known in the art, for example, fluid flow and/or pressure modulation devices used during well drilling and commonly referred to as “mud pulse” telemetry. In such embodiments, a fluid encoder 74 (e.g., a fluid pressure or flow rate modulator such as a valve) disposed on the floating platform 54 may be linked in signal communication with the control panel 12 and the hydraulic fluid conduit 72. When an operator operates the control panel to actuate any BOP 30, 56 on the BOP stack 50, the encoder 74 is activated to simultaneously send an actuation signal, e.g., in the form of pressure or flow rate changes along the hydraulic fluid conduit 72. At the BOP stack 50 end of the hydraulic fluid conduit 72, a receiver 76 (e.g., a pressure transducer) coupled into the hydraulic fluid conduit 72 detects the actuation signal and in turn conveys a corresponding signal (e.g. an electrical signal) to the interface module 62. When the interface module 62 detects such electrical signal, the interface module 62 in turn sends an actuation (electrical) signal to the initiator (44 in FIG. 3B) along the cable 60, and the kinetic BOP 30 is thereby actuated.
Some embodiments of a BOP stack according to this disclosure may also be implemented with an acoustic communication system. In such embodiments, the ship 54 may be provided with a conventional marine acoustic communication transmitter 78 in signal communication with the controller 12. When an operator uses the control panel (and correspondingly the controller 12 operates) to actuate a BOP 30, 56 on the BOP stack 50, the controller 12 may simultaneously operate the acoustic communication transmitter 78 to send an acoustic signal to the BOP stack 50 as is known in the art. At the BOP stack 50, an acoustic sensor 80 receives the acoustic signal and in turn conveys a corresponding signal to the interface module 62. When the interface module 62 detects such corresponding signal, the interface module 62 then sends an actuation (electrical) signal to the initiator (44 in FIG. 3B) along the cable 60, and the kinetic BOP 30 is thereby actuated.
Other embodiments may be implemented for actuating the kinetic BOP 30 using a conventional subsea remotely operated vehicle (ROV) 82. The interface module 62 may be provided with an actuation switch or button 84 wired to send an actuation signal to the initiator (44 in FIG. 3B) along the cable 60 when so operated by the ROV 82. In some embodiments, the interface module 62 may be implemented with a subsea receptacle 86 configured to receive electrical power from the ROV 82 through a telescoping arm on the ROV in any manner known in the art. Such embodiments may provide the actuation signal for the initiator (44 in FIG. 3B) in the event no electrical power was available at the BOP stack 50, e.g., by failure of any local electrical power source and/or the cable 64.
FIG. 4 shows another example embodiment of a BOP stack 50 according to this disclosure. The BOP assembly includes stacked conventional BOP units 56, which as previously described, are generally configured with rams that are actuated by hydraulic fluid under pressure. A kinetic BOP 30 is also included in the stack 50. All of the components are mounted on a frame 88 configured for disposal underwater for coupling to a wellhead at the see floor. Although not shown for clarity of illustration in FIG. 4, it will be appreciated that embodiments of this BOP stack 50 may be implemented with any and all of the components and features described with respect to the other disclosed BOP stack 50 embodiments for operation as disclosed herein.
The BOP stack 50 embodiment of FIG. 4 does not entail the use of pressurized accumulators (e.g., 66 in FIG. 3A) to operate the BOP unit(s) 56. The BOP assembly is equipped with a unitary module 90 consisting of a variable displacement pump 92, a subsea motor, and variable frequency drive (VFD). The separate module 90 components are coupled together to provide a compact unit. The variable displacement pump 92 in the module 90 is fluidly coupled to a hydraulic fluid reservoir 94 also mounted on the BOP stack 50. A controller bottle 96 is also linked to the module 90 to house local electronics and processors for operational control of the system. One or more batteries may be housed in the controller bottle 96 to power the system. A MUX 64 cable may also be coupled to the BOP stack 50 to provide power, data/signal communications, and/or fluid transfer from the floating platform 54. Some embodiments may include independent power lines 98 to remotely recharge the batteries from the platform 54 (e.g., to provide a trickle charge when the system is idle, to maintain a set charge). In some embodiments, electrical power may also be supplied to the batteries and/or the system via an ROV (e.g., 82 in FIG. 3A) coupling into a receptacle (e.g., 86 in FIG. 3A) on the interface module 62. In some embodiments, hydraulic fluid may also be provided to the reservoir 94 via the ROV. For clarity of illustration, not all conduits (e.g., hoses, cabling) are shown in FIG. 4.
As described herein, in the event it becomes necessary to actuate the kinetic BOP 30 to close off the through bore (34 in FIG. 2), an operator on the floating platform 54 can press a button on a control panel to send an electrical signal to the interface module 62 along the MUX cable 64 or remotely provide an activation signal to the controller 12′. The interface module 62 in response can simultaneously send electrical signals to the initiator 44 via the cable (e.g., 60 in FIGS. 3A, 3B) to actuate the kinetic BOP 30 and to the module 90 to activate the pump 92 to energize the rams on the BOP 56 via the hydraulic fluid from the reservoir 94. BOP stack 50 embodiments may also be implemented for acoustic activation via the acoustic transmitter/sensor configurations described herein. In response to the acoustic signaling, the interface module 62 can simultaneously send electrical signals to the initiator 44 to actuate the kinetic BOP 30 and to the module 90 to activate the pump 92 to energize the rams on the BOPs 56. Other embodiments may be implemented for simultaneously actuating the kinetic BOP 30 and the pump 92 to energize the rams on the BOPs 56 using the ROV to actuate the switch or button (e.g., 84 in FIG. 3A) on the interface module 62, which is wired to send the respective actuation signals. Elimination of the pressurized accumulator tanks significantly reduces the overall weight of the stack 50 structure (e.g., a reduction of approximately 200,000 lbs.) and reduces the likelihood of failure attributable to such underwater pressured systems. BP stack 50 embodiments may be implemented with conventional pumps 92 rated to provide sufficient fluid pressure to rapidly actuate the conventional BOP units 56.
In some embodiments of the disclosed BOP stacks 50, the interface module 62 may be programmed to automatically send an actuation (electrical) signal to the initiator (44 in FIG. 3B) to actuate the kinetic BOP 30 if a fail-safe event occurs (e.g., all power is out on the stack for a predetermined time period, accumulator pressure drops below a predetermined value, etc.). It will be appreciated by those skilled in the art that in some embodiments, the interface module 62 may be implemented with batteries, electronics, and processors configured with instructions to perform as described herein using conventional software and electronics protocols. The controller 12 may be correspondingly implemented.
Unlike conventional BOP systems that can receive only one actuation signal at a time due to the physical constraints imposed by the hydraulics of the systems, embodiments according to the present disclosure are capable of kinetic BOP actuation via multiple control signals, sent simultaneously or otherwise. Since the kinetic BOP 30 is actuated by an electrical signal, it is not constrained as to the number of actuation signals it can receive. As soon as the interface module 62 receives a triggering signal from among the various described modes, the actuation signal is immediately applied to the initiator (44 in FIG. 3B) and the kinetic BOP 30 is thereby actuated. One mode or all such modes may be actuated at once to trigger the interface module 62 to actuate the kinetic BOP 30. This provides for rapid wellbore control with greater reliability in the event a well shut off event occurs.
In light of the principles and example embodiments described and illustrated herein, it will be recognized that the example embodiments can be modified in arrangement and detail without departing from such principles. It will be appreciated by those skilled in the art that conventional hardware, electronics, and components may be used to implement the embodiments of this disclosure. Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible within the scope of the described examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
Patent Application
20240263541
