Patent ID: 12247452

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “lower,” and “upper” designate directions in the drawings to which reference is made. The words “inner” and “outer” refer to directions toward and away from, respectively, the geometric center of an object and designated parts thereof. Unless specifically set forth otherwise herein, the terms “a,” “an,” and “the” are not limited to one element but instead should be read as meaning “at least one.” “At least one” may occasionally be used for clarity or readability, but such use does not change the interpretation of “a,” “an,” and “the.” Moreover, the singular includes the plural, and vice versa, unless the context clearly indicates otherwise. “Including” as used herein means “including but not limited to.” The word “or” is inclusive, so that “A or B” encompasses A and B, A only, and B only. The terms “about,” “approximately,” “generally,” “substantially,” and like terms used herein, when referring to a dimension or characteristic of a component, indicate that the described dimension/characteristic is not a strict boundary or parameter and does not exclude minor variations therefrom that are functionally similar. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit thereof. The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. Two items that are “coupled” may be unitary with each other. The terminology set forth in this paragraph includes the words noted above, derivatives thereof, and words of similar import.

In one aspect, the present disclosure relates to a pumping system that is capable of reducing fluid hammer in a subsea drilling control system for remotely operating a BOP. BOP control functions include, but are not limited to, the opening and closing of hydraulically operated pipe rams, annular seals, shear rams designed to cut the pipe, a series of remote operated valves to allow controlled flow of drilling fluids, a riser connector, and well re-entry equipment.

As shown inFIG.1, in some embodiments, a system100may comprise a reservoir110, a pumping system120, a first control pod130, a second control pod140, a first subsea BOP component150coupled to the first control pod130, and a second subsea BOP component160coupled to the second control pod140.

The pumping system120may comprise a first pump122, a second pump124, a first motor126, and a controller128.

The first control pod130may comprise or be fluidly coupled to a first flow plate132having a port, a first upstream pressure sensor134, a first control pod valve136, and a first downstream pressure sensor.

The second control pod140may comprise or be fluidly coupled to a second flow plate142having a port, a second upstream pressure sensor144, a second control pod valve146, and a second downstream pressure sensor148. Some embodiments of the control pods130and140are known in the art and are described, for example, in U.S. Pat. App. Pub. No. US20090095464A1 and U.S. Pat. No. 9,291,020, the contents of each of which are incorporated herein by reference.

In some embodiments, the control pod valves136and146may independently comprise a two-way valve, a three-way valve, a four-way valve, a two-position two-way valve, a two-position three-way valve, or a three-position four-way valve. In some embodiments, the pressure sensors134,138,144, and148may independently comprise a transducer.

The first pump122may have a first inlet122aand a first outlet122b. The first inlet122amay be fluidly coupled to the reservoir110. In some embodiments, the reservoir110may comprise a container enclosing a hydraulic fluid. In some embodiments of systems or methods, the hydraulic fluid comprises an oil-based fluid, sea water, desalinated water, treated water, and/or water-glycol. In some embodiments, the hydraulic fluid comprises water-glycol. In some embodiments, the reservoir110may be the sea or a portion thereof. The first outlet122bmay be fluidly coupled fluidly coupled to the first control pod valve136and may be so coupled with or without being fluidly coupled to the port of the first flow plate132. The first control pod130may be fluidly coupled to the first subsea BOP component150so as to control the first subsea BOP component150. The first control pod130may be fluidly coupled to the reservoir110by a first return line131so as to return the hydraulic fluid from the first subsea BOP component150back to the reservoir110. The first upstream pressure sensor134may be positioned upstream of the first control pod valve136; may be positioned between the first flow plate132and the first control pod valve136; and may be configured to monitor the upstream pressure of the first control pod valve136. The first downstream pressure sensor138may be positioned between the first control pod valve136and the first subsea BOP component150and may be configured to monitor the downstream pressure of the first control pod valve136.

The second pump124may have a second inlet124aand a second outlet124b. The second inlet124amay be fluidly coupled to the reservoir110. The second outlet124bmay be fluidly coupled to the second control pod valve146and may be so coupled with or without being fluidly coupled to the port of the second flow plate142. The second control pod140may be fluidly coupled to the second subsea BOP component160so as to control the second subsea BOP component160. The second control pod140may be fluidly coupled to the reservoir110by a second return line141so as to return the hydraulic fluid from the second subsea BOP component160back to the reservoir110. The second upstream pressure sensor144may be positioned upstream of the second control pod valve146; may be positioned between the second flow plate142and the second control pod valve146; and may be configured to monitor the upstream pressure of the second control pod valve146. The second downstream pressure sensor148may be positioned between the second control pod valve146and the second subsea BOP component160and may be configured to monitor the downstream pressure of the second control pod valve146.

The first motor126may be coupled to the first pump122and the second pump124and configured to independently actuate the first pump122and the second pump124. In some embodiments, the first motor126may be electrically actuated. For example, the first motor126may comprise any suitable electric motor, such as, for example, a synchronous alternating current (AC) motor, asynchronous AC motor, brushed direct current (DC) motor, brushless DC motor, permanent magnet DC motor, and/or the like. In some embodiments, the first motor126may comprise a drive motor. In some embodiments, the first motor126may be hydraulically actuated.

In some embodiments, instead of using the first motor126to actuate the second pump124, a second motor may be used to actuate the second pump124.

The controller128may be coupled to the first motor126and configured to control (e.g., activate, deactivate, change or set a rotational speed of, change or set of a direction of, and/or the like) the first motor126. In some embodiments, the controller128may comprise an electric motor speed controller. In some embodiments, the controller128may comprise a variable frequency drive (VFD). In some embodiments, the controller128may comprise a programmable logic controller (PLC). The PLC may be configured to control a VFD, the control pod valve136, and/or the control pod valve146.

In some embodiments, the pumping system120may further comprise a battery coupled to the motor126and/or to the controller128.

In some embodiments, the pumping system120may comprise a third pump. In some embodiments, the pumping system120may comprise 2-20 pumps, e.g., 2-15 pumps, 2-10 pumps, 3-20 pumps, or 3-10 pumps. Each pump may be controlled by its own motor. Alternatively, a single motor may be configured to control one or more pumps.

The pumping system120permits engaging and disengaging each pump independently. The pumping system120may deliver hydraulic fluid at a predetermined pressure on demand to individual control pods and does not require regulators or other devices to control pressure. When a predetermined pressure for each pump is attained, each pump is de-stroked to limit pressure to each control pod valve, thereby reducing fluid hammer at each control pod. In some embodiments, a pump may be a swash-plate pump, which may be “de-stroked” by varying the angle of the swash plate to reduce or eliminate the output of pressurized fluid from the pump. In other embodiments, a pump may be “de-stroked” by limiting output in another fashion, such as by stopping or limiting a speed of a motor driving the pump, or by venting or diverting some or all of the fluid output of the pump. In some embodiments, each control pod valve will not open until the upstream pressure is no more than a threshold value (e.g., about 500 psi) higher or lower than the downstream pressure, as measured by the sensors. In some embodiments, each control pod valve will not open until the upstream pressure is as close to zero, as is practical given limits of the components, higher or lower than the downstream pressure, as measured by the sensors. As a result, each control pod valve is never subject to delta pressure, or is subject to the minimum practical delta pressure, and control components are less likely to fail as a result.

In some embodiments, the predetermined pressure for each pump is about zero psi to about 5000 psi. For example, the predetermined pressure is about zero psi, about 500 psi, about 1000 psi, about 1500 psi, about 200 psi, about 2500 psi, about 3000 psi, about 3500 psi, about 4000 psi, about 4500 psi, or about 5000 psi.

The pumping system120may set the predetermined pressure for each pump independently. For example, the pumping system120may set the predetermined pressure for the first pump122to be about 1500 psi, and the predetermined pressure for the second pump124to be about 3000 psi.

Related to the system100,FIG.2shows a system200in accordance with some embodiments. The system200may comprise a pumping system220. The pumping system220may comprise a plurality of pumps220operating in parallel, wherein each pump222may have a predetermined pressure. The pilot pressure, as indicated by the term “pilot” inFIG.2, is monitored to indicate if and/or when a function has been activated. A drop in pilot pressure (e.g., a rapid drop or drop beyond a predetermined threshold), for example, may be detected, indicating that a function has been activated and therefore supply pressure has been demanded, causing one or more pumps to deliver fluid to a control pod. When a predetermined pressure for each pump222is attained, each pump222may de-stroke, as indicated by the symbol221. As shown inFIG.2, a single motor may be configured to control or drive the plurality of pumps222.

The system200may comprise a control pod230configured to control a subsea BOP component250. The control pod230may comprise (a) a valve236athat may be fluidly coupled to an inlet of the BOP component250, and (b) a valve236bthat may be fluidly coupled to an outlet of the BOP component250. In some embodiments, the valve236bmay be fluidly coupled to a reservoir210.

In some embodiments, the control pod230may employ solenoid valves that may direct the pilot pressure to the valve236ato open the path between the pump222and the inlet/outlet of the BOP component250. The pilot pressure may be about 3,000 psi, and a pilot accumulator may be used to store a pressurized hydraulic fluid.

In some embodiments, the detection of control system command and solenoid valve operation may be performed by: (a) monitoring the pressure with a pressure transducer, and (b) capturing a control system command by detecting a rapid pressure drop in the pilot accumulator.

In some embodiments, the detection of control system command and solenoid valve operation may be performed by: (a) monitoring the flow rate at the outlet of the pilot accumulator with a flow meter or flow switch, and (b) capturing a control system command by detecting a rapid flow rate increase at the pilot accumulator output.

In some embodiments, the detection of control system command and solenoid valve operation may be performed by: (a) monitoring the pressure before valve236aand valve236bwith a pressure transducer while holding a low pressure (200 psi) before these valves, and (b) capturing a control system command by detecting a rapid pressure drop when valve236aor valve236bis opened. A gas-charged accumulator may be used to increase the control system command capture capability.

Related to the pumping system120,FIG.3shows a pumping system300in accordance with some embodiments. The pumping system300may comprise a plurality of pumps322operating in parallel, where each pump322may have a predetermined pressure. Each pump322may be independently controlled by a motor326.

In one aspect, the present disclosure relates to a manifold system that is capable of reducing fluid hammer in a subsea drilling control system for remotely operating a subsea BOP.

As shown inFIG.4, in some embodiments, a system400may comprise a reservoir410, a pump420, a manifold system430, a first control pod440, a second control pod442, a first subsea BOP component450, and a second subsea BOP component452.

The manifold system430may comprise an upstream pressure sensor432, a first valve434a, a second valve434b, a third valve which may be referred to as a dump valve434c, a first downstream pressure sensor436, and a second downstream pressure sensor438. Any of the valves may include any suitable device for providing flow or pressure relief, including a manual valve, hydraulic valve, pneumatic valve, PRV and/or another suitable valve.

The pump420may have an inlet420aand an outlet420b. The inlet420aof the pump420may be fluidly coupled to the reservoir410. In some embodiments, the reservoir410may comprise a container enclosing a hydraulic fluid. In some embodiments, any reservoir—including, for example, the reservoir410—may be the sea or a portion thereof, or the atmosphere or a portion thereof. The outlet420bof the pump420may be fluidly coupled to the upstream pressure sensor432.

The upstream pressure sensor432may be fluidly coupled to an inlet of the first valve434a, an inlet of the second valve434b, and an inlet of the dump valve434c. The upstream pressure sensor432may be configured to monitor an upstream pressure of the valves434a,434b, and434c.

In some embodiments, each of the pressure sensors432,436, and438may comprise a transducer.

An outlet of the first valve434amay be fluidly coupled to the first downstream pressure sensor436, which may be configured to monitor a downstream pressure of the first valve434a. The first downstream pressure sensor436may be fluidly coupled the first control pod440and may be so coupled by being fluidly coupled to a first flow plate441. The first flow plate441may comprise a port. The first control pod440may further comprise a first control pod valve443that may be fluidly coupled to the first subsea BOP component450so as to control the first subsea BOP component450.

An outlet of the second valve434bmay be fluidly coupled to the second downstream pressure sensor438, which may be configured to monitor a downstream pressure of the second valve434b. The second downstream pressure sensor438may be fluidly coupled to the second control pod442and may be so coupled by being fluidly coupled to a second flow plate444. The second flow plate444may comprise a port. The second control pod442may further comprise a second control pod valve445that may be fluidly coupled to the second subsea BOP component452so as to control the second subsea BOP component452.

An outlet of the dump valve434cmay be fluidly coupled to the reservoir410. The dump valve434cmay be used for availability testing, i.e., testing that a predetermined pressure may be attained before applying the predetermined pressure to the first control pod440or the second control pod442. As such, the dump valve434cpermits an offline, nonintrusive test while conducting operations. The dump valve434cmay be configured to reset the upstream pressure of the first valve434aand/or the second valve434bto about zero psi.

In some embodiments, each of the valves434a,434b,434c,443, and445may comprise a two-way valve, a three-way valve, or a four-way valve, a two-position two-way valve, a two-position three-way valve, or a three-position four-way valve.

The pump420may be configured to set a pressure output based on the downstream pressure as measured by the downstream pressure sensors436or438. In some embodiments, the valves434aor434bwill not open until the upstream pressure (as may be measured by the upstream pressure sensor432) is no more than about 500 psi higher or lower than the downstream pressure, as measured by the downstream pressure sensors436or438. In some embodiments, each control pod valve will not open until the upstream pressure is as close to zero, as is practical given limits of the components, higher or lower than the downstream pressure, as measured by the sensors. As the control pod440or442attains a predetermined pressure, the valve434aor434bis closed to isolate the pressure.

In some embodiments, the system400may further comprise a motor coupled to the pump420and configured to control the pump420. In some embodiments, the system400may further comprise a controller coupled to the motor and configured to control (e.g., activate, deactivate, change or set a rotational speed of, change or set of a direction of, and/or the like) the motor. In some embodiments, the controller may comprise an electric motor speed controller. In some embodiments, the controller may comprise a VFD. In some embodiments, the controller may comprise a PLC. The PLC may be configured to control a VFD, and/or the valves434a,434b,434c,443, and445. In some embodiments, the system400may further comprise a battery coupled to the controller.

Related to the system400,FIG.5shows a system500comprising a reservoir510, a pump520, a motor522, an integrated manifold assembly (IMA)530, a control pod540, a first subsea BOP component550, and a second subsea BOP component552.

The IMA530may comprise an upstream pressure sensor532, a first main-stage valve534a, a second main-stage valve534b, a dump valve534c, a first downstream pressure sensor536, and a second downstream pressure sensor538.

The control pod540may comprise a first flow plate541having a port, a first control pod valve543, a second control pod valve546, a second flow plate544having a port, a third control pod valve545, and a fourth control pod valve547.

The first main-stage valve534amay be fluidly coupled to the first control pod valve543and the second control pod valve546and may be so coupled by being fluidly coupled to the first flow plate541, which may be fluidly coupled to the second control pod valve543. Both control pod valves543and546may be fluidly coupled to the first subsea BOP component550. The first control pod valve543may be configured to control the first subsea BOP component550. The second control pod valve546may be configured to close a ram (or other BOP components).

The second main-stage valve534bmay be fluidly coupled the third control pod valve545and the second control pod valve547and may be so coupled by being fluidly coupled to the second flow plate544, which may be fluidly coupled to the third control pod valve545. Both control pod valves545and547may be fluidly coupled to the second subsea BOP component552. The third control pod valve545may be configured to control the second subsea BOP component552. The fourth control pod valve547may be configured to close an annular (or other BOP components).

Related to the systems400and500,FIG.6shows a system where two IMAs (integrated manifold assemblies) may be operating in parallel. The two IMAs may comprise a ZED IMA and a generic IMA. Each of the ZED IMA and the IMA may be configured to provide hydraulic fluid at a particular pressure to a particular type of device, which may be a hydraulically operated device of a BOP.

The operations of the pumping system described herein under drilling mode or non-drilling mode are described inFIGS.7-9. Under drilling mode, typically about 50% of the control pod valves are open to their stack mounted functions, routinely (e.g., about every 12 hours) the system ramps pressure to confirm hydraulic integrity, as illustrated inFIG.7. As indicated inFIG.7, in an embodiment of a method according to the invention, pressure may be cycled approximately every 12 hours, with pressure increasing stepwise to an appropriate pressure to operate various BOP functions, including annulars, LMRP, WH, rams/valves, and shear rams.FIG.8is a flowchart illustrating a method800of confirming hydraulic integrity in the system100under drilling mode. The method800comprises at step810, the control pod130receiving command to confirm hydraulic integrity. At step820, the method800comprises closing the control pod valve136if not closed or keeping it closed. At step830, the pump122increases pressure by no more than about 500 psi. After the pressure increase, at step840, the pressure sensors134and138measure the upstream and downstream pressures respectively, thereby providing a pressure difference. At step850, the pump122is de-stroked. Subsequently at step860, when the pressure difference is no more than about 500 psi, the control pod valve136is open. Steps820-860may be repeated as many times as needed until a desirable pressure is reached at the control pod valve136. In some embodiments the desirable pressure is about 5000 psi, about 4500 psi, about 4000 psi, about 3500 psi, or about 3000 psi. At step870, the pressure at the control pod valve136is reduced to about zero psi by venting the hydraulic fluid back to the reservoir110.

Confirmation of hydraulic integrity may result in eliminating or substantially eliminating hydraulic pressure spikes in a system. In some embodiments, the present disclosure relates to a method of eliminating hydraulic pressure spikes in a system comprising the pumping system described herein. In some embodiments, the method comprises: (a) selecting a control pod valve from a plurality of control pod valves, (b) monitoring the upstream and downstream pressures of the selected control pod valve, and (c) opening the selected control pod valve when the upstream pressure is no more than about 500 psi higher or lower than the downstream pressure.

FIG.9is a flowchart illustrating a method900of delivering pressure to the system100under non-drilling mode. Non-drilling mode, may include, for example, various well-control events. As examples, non-drilling mode may include closing a ram, shearing or sealing an annular, aligning a tubular, conducting a test (e.g., a pressure test), adjusting a drilling string, or any event associated with adjusting (e.g., closing or altering access to) the wellbore. The method900comprises at step910, the pump122receiving command to increase pressure. At step920, before the pump122increases the pressure, the method900comprises opening the control pod valve136. At step930, the pump122increases the pressure to a predetermined pressure. At step940, the pump122de-strokes to limit the pressure to the control pod valve136.

The operations of the manifold system described herein under drilling mode or non-drilling mode are described inFIGS.7and10-11. Under drilling mode, typically about 50% of the control pod valves are open to their stack mounted functions, routinely (e.g., about every 12 hours) the system ramps pressure to confirm hydraulic integrity, as illustrated inFIG.7.FIG.10is a flowchart illustrating a method1000of confirming hydraulic integrity in the system400under drilling mode. The method1000comprises at step1010, the control pod440receiving command to confirm hydraulic integrity. At step1020, the method1000comprises closing the valve434aand control pod valve443or keeping the valve434aand control pod valve443closed. At step1030, the pump420increases pressure by no more than about 500 psi. After the pressure increase, at step1040, the pressure sensors432and436measure the upstream and downstream pressures respectively, thereby providing a pressure difference. At step1050, the method1000comprises de-stroking the pump. Subsequently at step1060, when the pressure difference is no more than about 500 psi, the method1000comprises opening the valve434aand control pod valve443. At step1070, the method1000comprises closing valve434ato isolate the pressure. Steps1020-1070may be repeated as many times as needed until a desirable pressure is reached at the control pod valve443. In some embodiments the desirable pressure is about 5000 psi, about 4500 psi, about 4000 psi, about 3500 psi, or about 3000 psi. At step1080, the pressure at the control pod valve443is reduced to about zero psi by venting the hydraulic fluid back to the reservoir410.

In some embodiments, the present disclosure relates to a method of eliminating hydraulic pressure spikes in a system comprising the manifold system described herein. In some embodiments, the method comprises: (a) selecting a valve in the manifold system from the plurality of valves, (b) monitoring the upstream and downstream pressures of the selected valve, and (c) opening the selected valve when the upstream pressure is no more than about a threshold value higher or lower than the downstream pressure. In some embodiments, the threshold value is about 500 psi.

FIG.11is a flowchart illustrating a method1100of delivering pressure to the system400under non-drilling mode. The method1100comprises at step1110, the pump420receiving command to increase pressure. At step1120, before the pump420increases the pressure, the method1100comprises opening the valve434aand the control pod valve443. At step1130, the pump420increases the pressure to a predetermined pressure. At step1140, the pump420de-strokes to limit the pressure to the control pod valve443.

In some embodiments, the control pod in the pumping system or manifold system may be coupled to an electronic multiplex control system (“MUX”), through which an operator on the surface may control and/or monitor BOP functions and hydraulic supply. (SeeFIG.6.) In a simple sense, the MUX allows an operator to control BOP functions by the push of buttons or the like. For example, the operator closes an annular by pressing a button or inputting an electronic command to signal the hydraulic system to close the annular. In some embodiments, the present invention is integrated into an existing multiplex system such that the initiation of backup hydraulic supply may be commanded by the push of a button. In addition, software may allow the switch between normal flow and backup flow to be transparent in that the operator pushes the same button to control a particular function whether normal or backup flow used.

Valves of the present disclosure (e.g., main-stage valves) may comprise any suitable valve, such as, for example spool valves, poppet valves, ball valves and/or the like, and unless specified, may comprise any suitable configuration, such as, for example, two-position two-way (2P2W), 2P3W, 2P4W, 3P4W, and/or the like. Valves of the present disclosure may be normally closed (e.g., which may increase fault tolerance, for example, by providing failsafe functionality), or normally open. In some embodiments, valves that are configured to directly control hydraulic fluid communication to and/or from a hydraulically actuated device are configured to withstand hydraulic fluid pressures of up to 7,500 pounds per square inch gauge (psig) or larger and ambient pressures of up to 5,000 psig, or larger. Any of the valve may be actuated in any suitable fashion, such as, for example, hydraulically, pneumatically, electrically, mechanically, and/or the like.

In some embodiments, the pumping system and the manifold system described herein may be coupled together in the same system to work cooperatively to reduce fluid hammer in subsea drilling control systems.

In addition, any combination of two or more features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present disclosure as defined by the appended claims.