See Application Data Sheet.
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The present invention relates to a suction pile. More particularly, the present invention relates to a suction pile installed without a remote operated vehicle (ROV). Even more particularly, the present invention relates to a subsea support system having a suction pile installed by an installation tool assembly and vent valve assembly.
A suction pile (also known as a suction caisson, a suction anchor, and a suction bucket) is used to moor a subsea drilling rig, or other pile structure, to the ocean floor. The suction pile is attached to the ocean floor, and rig or offshore windfarm structures are anchored to the attached suction pile. The suction pile is comprised of a generally tubular body, dropped into the water and floated down to the ocean floor. The open end of the tubular body embeds into the ocean floor, like an upside down bucket faced down in the soil. There is a closed end of the tubular body with a vent hatch. The vent hatch has an opened position and a closed position, and a remote operated vehicle (ROV) is used to move the vent hatch between these two positions. The opened position is used during deployment to the ocean floor, with water flowing through the tubular body by the vent hatch. Once landed, the closed position is used to seal the suction pile, so that air and water remaining in the tubular body are pumped out. Soil of the ocean floor is sucked into the tubular body, solidly embedding the suction pile onto the ocean floor. The embedded and filled suction pile forms a solid base for mooring offshore structures. Suction piles are known as anchoring means for rigs, oil and gas exploration installations, and offshore windfarms.
Variations of suction piles are known in the prior art. For example, United States Patent Publication No. 20060127187, published for Raines on Jun. 15, 2006, discloses a conventional anchor system with a variation on the suction pile structure. There is an elongated hollow anchor element releasably attached to an installation element.
The use of ROV technology to facilitate the embedding of a suction pile is also well known. United States Patent Publication No. 20090297276, published for Foo et al., on Dec. 3, 2009 discloses installation using the ROV instead of an aiming mechanism on the anchoring element of the suction pile. U.S. Pat. No. 6,719,496, issued to Eberstein on Apr. 13, 2004, also describes a system with ROV intervention to install a suction pile. The ROV with pump capability closes the flood valves on the top of the suction pile and attaches to the pumping port of the suction pile. The pump of the ROV operates to draw down the suction pile. The ROV disconnects from the pump port and connects a mooring line to second the load connection.
Variations of the vent hatch or vent cap of the suction pile are also known in the prior art. The primary type of vent hatch for a suction pile is the hinged cap. United States Patent Publication No. 20130220206, published for Mogedal et al on Aug. 29, 2013, shows a vent cap as a hinged cap with a frame to insure alignment of the cap plate over the hatch. Another type of vent hatch is the butterfly valve, shown in U.S. Pat. No. 6,719,496, issued to Eberstein on Apr. 13, 2004, with a cap plate swiveling over the hatch for opening and closure. Some vent hatches are combinations of the hinged cap and the butterfly valves, such as U.S. Pat. No. 6,322,439, issued to David on Nov. 27, 2001. The hinge elements transition between the traditional flipping hinged cap with the cap plate lifted from the hatch and the traditional butterfly vent cap with the cap plate swiveling over the hatch.
It is an object of the present invention to provide an embodiment of a suction pile installed without a remote operated vehicle (ROV).
It is another object of the present invention to provide an embodiment of a suction pile installed by a detachable installation tool having motors.
It is another object of the present invention to provide a subsea system installing a suction pile with a vent valve assembly for sealing and for embedding.
It is still another object of the present invention to provide a subsea system installing a suction pile with a vent valve assembly having a side port for embedding.
It is another object of the present invention to provide an embodiment of a subsea system installing a suction pile at a subsea location with a detachable installation tool.
It is still another object of the present invention to provide a subsea system installing a suction pile with an installation tool assembly having a detachable connection to a vent valve assembly on the suction pile.
It is an object of the present invention to provide an embodiment of a subsea system installing a suction pile with retrievable components.
It is another object of the present invention to provide a subsea system with a suction pile, vent valve assembly and a detachable installation tool deployed from a surface while attached together as a single unit.
It is still another object of the present invention to provide a subsea system with a suction pile anchored by a detachable installation tool with motors to be retrieved from the subsea location.
These and other objectives and advantages of the present invention will become apparent from a reading of the attached specification.
Embodiments of the present invention include a subsea support structure comprised of a suction pile. The suction pile can be used to anchor an offshore drilling rig or windfarm. The suction pile can be placed in deep water or relatively shallow water, depending upon the purpose of installation (drilling rig, windfarm, etc.) supported by the suction pile. The installation can have cranes, helipads, drills, turbines, windmills, and other components. The present invention includes a suction pile, a vent valve assembly, and an installation tool assembly. The suction pile is comprised of a generally cylindrical body having a top pile surface with a pile vent opening on a closed end and a pile skirt on an opened end, and the vent valve assembly is made integral with the pile vent opening. The installation tool assembly is removably attached to the vent valve assembly by a clamping device.
The vent valve assembly of the present invention can include a top vent valve plate, a lower connection interface made integral with the top vent valve plate, and a center stem assembly extending through the top vent valve plate. A plurality of vent valve stem assemblies connects the top vent valve plate to a bottom vent valve body. The bottom vent valve body has a tubular connection portion made integral with the pile vent opening, a first sealing portion, a second sealing portion, and a side port portion between the first and second sealing portions. A seal plate is attached to the center stem assembly so that rotating the center stem assembly actuates the seal plate up and down the center stem assembly. The seal plate can be set in the first sealing portion, the second sealing portion, or the side port portion of the bottom vent valve body. A rod guide in the bottom vent valve body aligns the center stem assembly.
The installation tool assembly of the present invention can include a lower mounting plate being removably engaged to the top vent valve plate and having a center lower mounting hole. The lower connection interface of the vent valve assembly inserts through the center lower mounting hole, so that a clamp centered on the lower mounting plate can engage the lower connection interface. There is a first motor attached to the lower mounting plate to actuate the clamp. The installation tool assembly also includes an upper mounting plate attached to the lower mounting plate and having a center upper mounting hole aligned with the center lower mounting hole. An upper connection interface attached to the bottom side of the upper mounting plate extending downward to contact the lower mounting plate in the clamp on the lower mounting plate. The clamp works to connect the vent valve assembly to the installation tool assembly.
Embodiments of the installation tool assembly further include a locking means actuated by a second motor on a top side of the upper mounting plate. The locking means stops rotation of the center stem assembly so that the seal plate can be held in different positions within the bottom vent valve body. In some embodiments, the seal plate in a second sealed position corresponds to actuating the stop member to prevent rotation of the center stem assembly. There is a top installation tool plate attached to the upper mounting plate and the lower mounting plate by a plurality of installation tool stem assemblies extending through all three plates. A third motor is mounted on a lower side of the top installation tool plate, and the third motor rotates a hex drive rod extending down through the upper connection interface and connecting to the center stem assembly of the vent valve assembly. The third motor of the installation tool assembly can drive the seal plate of the vent valve assembly.
In the present invention, the vent valve assembly must be able to seal and to embed the suction pile. To embed, there is a side port opening in the side port portion of the bottom vent valve body. The seal plate can be set in the second sealed portion to open the side port opening. Water can be suctioned from the suction pile and bottom vent valve body to anchor the suction pile into the soil. The seal plate can be lowered to the first sealed portion to close the side port opening and the suction pile, when the suction pile is set at the desired depth. In some embodiments, a tubular member is attached to the side port opening to remove the water, and the lower mounting plate, the upper mounting plate, and the top installation tool plate can have ring frames to support the tubular member. The lower mounting plate and the upper mounting plate can also have accessory plates to protect the first motor between the mounting plates.
Embodiments of the clamp of the present invention include a first arcuate arm with a first locking groove, and a second arcuate arm with a second locking groove. The first motor has an actuating member to move the arcuate arms closer together to clamp and farther apart to release. The lower connection interface and the upper connection interface fit into both grooves cooperatively in a locked connection of the vent valve assembly and the installation tool assembly.
Embodiments of the present invention include the method for installation of a subsea support structure. The system is assembled on barge at the surface before being deployed subsea. The clamp is opened, and the hex drive rod is inserted into the center stem assembly. The lower connection interface and the upper connection interface cooperative fit within locking grooves of the clamp, and then the clamp is closed. The hex drive rod rotates by the third motor to raise the seal plate above the bottom vent valve body for a opened position. Then, the entire system is deployed to the subsea location.
Once the suction pile is self-embedded by weight, the seal plate is closed to the second sealed position, which opens the side port opening and closes the bottom vent valve body and suction pile. Water is pumped from the suction pile and bottom vent valve body to suction soil and set the suction pile to the desired depth. At the desired depth, the seal plate is actuated to the first sealed position to close the side port opening and the suction pile. The suction pile is now anchored in place at the desired depth.
The clamp is now opened again by the first motor. The lower connection interface separates from the upper connection interface, and the hex drive rod releases from the center stem assembly as the installation tool assembly is raised toward the surface. The installation tool assembly is now released and can be returned to the surface for reuse. When there is a tubular member connected to the side port opening, the tubular member must also be separated from the vent valve assembly. Various connections to the surface, such as motor umbilicals and tubular member pumps, can be attached to the structure of the present invention to provide power and suction.
Offshore installations or facilities can have cranes, helipad, turbines, generators, windfarms, and other equipment to sustain industrial processes and human lives in the middle of the ocean. The equipment is heavy and difficult to transport, so permanent placement in the ocean requires a strong support structure with anchoring to the ocean floor. The anchoring includes subsea support structures comprised of suction piles. A suction pile is deployed from the surface and lowered to the subsea location. The suction pile is embedded into the soil to anchor other supports for the offshore installation. The present invention provides a subsea support structure comprised of a suction pile to be installed without less equipment and without a remote operated vehicle (ROV).
The vent valve assembly 30 of the present invention can include a top vent valve plate 32, a lower connection interface 34 made integral with the top vent valve plate 32, and a center stem assembly 36 extending through the top vent valve plate 32.
A plurality of vent valve stem assemblies 42 connects the top vent valve plate 32 to a bottom vent valve body 44. Each vent valve stem assembly 42 is arranged on an edge of the bottom vent valve body 44 facing and extending upward toward the top vent valve plate 32. The vent valve stem assemblies 42 maintain position of the top vent valve plate 32 relative to the bottom vent valve body 44.
Embodiments of the seal plate 58 are shown in
In some embodiments, there is a sealing means 72 around a perimeter of the circular plate body 60 of the seal plate 58.
The installation tool assembly 80 includes a lower mounting plate 82 removably engaged to the top vent valve plate 32. The lower mounting plate 82 of the installation tool assembly 80 and the top vent valve plate 32 of the vent valve assembly 30 abut each other when the installation tool assembly 80 and the vent valve assembly 30 are connected. The lower mounting plate 82 has a center lower mounting hole 84 aligned with the center stem assembly 36 of the vent valve assembly 30. The lower connection interface 34 of the vent valve assembly 30 can insert through the center lower mounting hole 84, so that a clamp 86 centered on the lower mounting plate 82 can engage the lower connection interface 34. The installation tool assembly 80 further includes a first motor 88 attached to the lower mounting plate 82 and the clamp 86. The first motor 88 actuates the clamp 86 to open and close.
An embodiment of the clamp 86 is shown in detail in
Embodiments of the installation tool assembly 80 further include a locking means 124 actuated by a second motor 126 on a top side 96 of the upper mounting plate 90 in
Embodiments with the installation tool stem assemblies 132 show the alignment of the vent valve assembly 30 and the installation tool assembly 80. The lower mounting plate 82 is adjacent and contacts the top vent valve plate 32.
The upper mounting plate 90 can also be comprised of a plurality of upper stem holes 140, and the top installation plate 130 can be comprised of a plurality of tool plate holes 142. Each upper stem hole 140 and each tool plate hole 142 are aligned with a corresponding installation tool stem assembly 132, such that the corresponding installation tool stem assembly 132 inserts through a respective upper stem hole 140 and a respective tool plate stem hole 142. The installation tool stem assemblies 132 stabilize position of the plates 82, 90, 130 relative to each other and maintain alignment. In additional embodiments of
The installation tool assembly 80 further includes a third motor 146 mounted on a lower side 134 of the top installation tool plate 130.
In the embodiments with the hex drive rod 148, the locked position of the stop member 128 corresponds to the stop member 128 in friction fit engagement with the hex drive rod 148. The edge of an L-shaped block abuts a hex surface of the hex drive rod 148 so that the hex drive rod 148 cannot rotate. The unlocked position of the stop member 128 corresponds to the stop member 128 releasing from friction fit engagement with the hex drive rod 148. Actuating the stop member 128 with the second motor 126 to retract the edge from the hex surface allows the hex drive rod 148 to rotate.
In the present invention, the vent valve assembly 80 must be able to seal and to embed the suction pile 10. To embed, there is a side port opening 54 in the side port portion 52 of the bottom vent valve body 44. The seal plate 58 can be set in the second sealing portion 50 to open the side port opening 54. Water can be suctioned from the suction pile 10 and bottom vent valve body 44 to anchor the suction pile 10 into the soil. The seal plate 58 can be lowered to the first sealing portion 48 to close the side port opening 54 and the suction pile 10, when the suction pile 10 is set at the desired depth.
In the present invention, the tubular member 154 can be supported by the installation tool assembly 80. The connection and removal of the tubular member 154 can be coordinated with the installation tool assembly 80.
Embodiments of the method of the present invention are shown in sequence from
The next sequence of steps is shown in
When there is a tubular member 154 connected to the side port opening 54, the tubular member 154 must also be separated from the vent valve assembly. In this embodiment, the step of pumping water from the suction pile 10 includes pumping water through the tubular member 154 from the side port connector 56 and the side port opening 54. There can also be various connections to the surface, such as motor umbilicals 150. Connecting the motor umbilicals 150 can be performed during the step of assembling on barge. The motor umbilicals 150 remain attached to the installation tool assembly 80, so that there is no removal in the method of installing the suction pile 10. Other connections to the surface may provide other resources and power to the installation tool assembly 80 at the subsea location.
The present invention is a subsea support structure for an offshore installation to be maintained in the middle of the ocean for the performance of industrial processes, and sometimes supporting human lives. The subsea support structure includes a suction pile anchored at a desired depth. The suction pile of the present invention can be installed without a remote operated vehicle (ROV). The suction pile can be closed, and water can be pumped from the suction pile for embedding without an ROV. The valves can be opened and closed at the subsea location by the installation tool assembly attached to the suction pile, instead of sending an ROV to navigate the ocean currents. There is no need to make new connections and align ROV tools with knobs and valves on the suction pile. Less equipment is required because there is no need for the ROV and supporting equipment for the ROV. There is no need for the skilled personnel to pilot the ROV because all motors and actuators are already aligned to perform the required functions.
Even with the motors and other components aligned on the suction pile, the motors and other components are detachable from the suction pile. When anchored at the desired depth, the motors and other components are retrieved for reuse in another installation of another suction pile. The equipment is not lost with the permanent placement of the suction pile. The vent valve assembly seals, embeds, and seals again. A side port on the vent valve assembly can be opened in the opened position. The side port can also be sealed for pumping to embed. Then, the side port can be sealed another time for permanent anchoring at the desired depth.
The entire installation tool assembly can be detached from the suction pile and vent valve assembly. The lower connection interface and the upper connection interface are clamped together in the installation tool assembly, so that the retrievable component includes the clamping device. The vent valve assembly still should have a suitable complementary structure to the upper connection interface, such as the lower connection interface of the present invention, in order to allow for the clamping to connect the installation tool assembly and the vent valve assembly. The suction pile, vent valve assembly and detachable installation tool assembly are deployed from a surface while attached together as a single unit. The connections and alignments can be checked on barge, so that the system is ready to embed and anchor upon reaching the desired location. These alignments and relationship between components are also retrieved on the installation tool assembly of the present invention.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated structures, construction and method can be made without departing from the true spirit of the invention.
Number | Name | Date | Kind |
---|---|---|---|
6322439 | David | Nov 2001 | B1 |
6719496 | Von Eberstein | Apr 2004 | B1 |
20060127187 | Raines | Jun 2006 | A1 |
20090297276 | Foo et al. | Dec 2009 | A1 |
20130220206 | Mogedal | Aug 2013 | A1 |
20150191220 | Mohrfield | Jul 2015 | A1 |
20160090709 | Mohrfeld | Mar 2016 | A1 |