US20180245302A1 - Anchoring system and method - Google Patents
Anchoring system and method Download PDFInfo
- Publication number
- US20180245302A1 US20180245302A1 US15/964,996 US201815964996A US2018245302A1 US 20180245302 A1 US20180245302 A1 US 20180245302A1 US 201815964996 A US201815964996 A US 201815964996A US 2018245302 A1 US2018245302 A1 US 2018245302A1
- Authority
- US
- United States
- Prior art keywords
- anchoring system
- water
- skirt
- tube sheet
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/24—Prefabricated piles
- E02D5/28—Prefabricated piles made of steel or other metals
- E02D5/285—Prefabricated piles made of steel or other metals tubular, e.g. prefabricated from sheet pile elements
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D11/00—Methods or apparatus specially adapted for both placing and removing sheet pile bulkheads, piles, or mould-pipes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/60—Piles with protecting cases
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D7/00—Methods or apparatus for placing sheet pile bulkheads, piles, mouldpipes, or other moulds
- E02D7/20—Placing by pressure or pulling power
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D9/00—Removing sheet piles bulkheads, piles, mould-pipes or other moulds or parts thereof
- E02D9/02—Removing sheet piles bulkheads, piles, mould-pipes or other moulds or parts thereof by withdrawing
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2250/00—Production methods
- E02D2250/0053—Production methods using suction or vacuum techniques
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2250/00—Production methods
- E02D2250/0061—Production methods for working underwater
- E02D2250/0092—Production methods for working underwater using hydraulical means
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2300/00—Materials
- E02D2300/0026—Metals
- E02D2300/0029—Steel; Iron
Definitions
- This invention is in the field of anchoring systems.
- the invention relates to submerged anchoring systems and methods.
- an anchoring system having plural water tubes, each water tube defining a longitudinal channel, each longitudinal channel having an open end and a closed end opposite to the open end, a connecting structure maintaining the plural water tubes in rigid relation to one another, and each water tube of the plural water tubes extending from the connecting structure at least in a first direction, the longitudinal channels extending in the first direction from the respective open ends to the respective closed ends.
- the connecting structure may comprise a cap.
- ballasting unit having a housing open at a first end, a flexible wall separating the first end of the housing from a second end to define an air chamber at the second end, the flexible wall comprising a material selected to withstand undersea pressure, and to maintain a pressure differential in use of the ballasting unit.
- an anchoring system may be configured to be installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material.
- the anchoring system may comprise: a tube sheet that may have a top side and a bottom side; an access tube may define a flow channel through the tube sheet from the top side to the bottom side; and a plurality of water tubes may pass through the tube sheet.
- the anchoring system may be cylindrical.
- Each of the plurality of water tubes may define a longitudinal channel from the top side to the bottom side of the tube sheet.
- Each longitudinal channel may comprise an open end at the top side and a closed end below the bottom side.
- a plurality of flow channels may pass through the tube sheet from the top side to the bottom side.
- a skirt may extend from the bottom side of the tube sheet and may define a volume within the skirt below the tube sheet encompassing at least a portion of the water tubes and the flow channels.
- the anchoring system may further comprise a shock absorber that may be coupled to the closed end of at least one of the plurality of water tubes.
- the shock absorber may comprise an air chamber.
- the air chamber may comprise at least one flexible wall configured to withstand undersea pressure and may maintain a pressure differential between the longitudinal flow channel and the air chamber.
- the at least one flexible wall may comprise a neoprene material.
- a cylinder may have the at least one flexible wall closing the closed end longitudinal channel.
- the shock absorber may withstand pressures in excess of 20,000 PSI.
- the shock absorber may be rounded at a bottom end to facilitate penetration into the bottom material.
- the anchoring system may further comprise an excavation pump operatively coupled to the access tube on the top side of the tube sheet.
- the excavation pump may transfer at least a portion of the bottom material from the bottom side to the top side of the tube sheet.
- the anchoring system may further comprise at least one valve port fluidly coupled to the plurality of flow channels.
- the plurality of flow channels may be located near an edge of the tube sheet and an edge of the skirt.
- the at least one valve port may be configured to remove water, the bottom material, and a combination of water and the bottom material from the volume of the skirt.
- An injected material may be injected into the at least one valve port and deposited within the volume of the skirt.
- the injected material may comprise barite mud.
- the anchoring system may further comprise a reinforcement structure coupled to the skirt.
- the reinforcement structure may resist lateral motion and maintains the position of the skirt.
- a method of installing an anchoring system on a bottom of a body of water the bottom of the body of water being formed of a bottom material.
- the method may comprise submerging the anchoring system and lowering the anchoring system until a bottom of a skirt rests on the bottom of the body of water.
- the skirt may define an inner volume with the bottom of the body of water.
- the method may comprise pumping, using an excavation pump, the bottom material from the inner volume through an access tube to produce a negative pressure within the inner volume.
- the negative pressure may be configured to pull the anchoring system beneath the bottom of the body of water.
- the method may comprise continuing to pump the bottom material from the inner volume until the bottom of the skirt reaches a solid substrate.
- the method may comprise injecting a mud denser than the bottom material into the inner volume using one or more flow channels.
- the method may comprise dissipating lateral motion, vertical motion, and a combination of lateral and vertical motion of the anchoring system using a plurality of shock absorbers on a bottom end of a plurality of water tube within the skirt.
- the method may further comprise stabilizing the anchoring system with a reinforcement structure.
- the mud may comprise barite.
- a method of removing an anchoring system installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material may comprise providing suction to at least one flow channel to withdraw a mud denser than the bottom material from a skirt defining an inner volume of the anchoring system, the skirt in contact with a solid substrate of the body of water.
- the method may comprise pumping water through an access tube to produce a positive pressure within the inner volume of the anchoring system causing the skirt to lift from the solid substrate of the body of water.
- the method may comprise continuing to pump water into the inner volume until the anchoring system becomes free from the bottom of the body of water.
- the method may comprise lifting the anchoring system from the bottom of the body of water.
- FIG. 1 is a perspective view of an anchoring system without a skirt
- FIG. 2 is a side perspective view of the anchoring system with a skirt about an upper part of the anchoring system;
- FIG. 3 is a side perspective view of the anchoring system with the skirt extending further than the skirt shown in FIG. 2 ;
- FIG. 4 is a side perspective view of the anchoring system
- FIG. 5 is a side view of a ballasting unit for the anchoring system
- FIG. 6 shows the anchoring system with a flange connection for connecting to a pump to pump fluid from the unit, and a flange cover;
- FIG. 7 shows the anchoring system with pump and hydraulics on a bed or floor of a body of water
- FIG. 8 shows a stabilizing reinforcement structure for the anchoring system
- FIG. 9 is a top view of the anchoring system with the stabilizing reinforcement structure.
- the aspects described herein may serve as a mooring system in areas of the ocean, rivers, and/or other bodies of water where poor anchorage or holding ground exists.
- the aspects herein may be particularly applicable to sandy or silt ocean floor such as the Gulf of Mexico.
- the aspects herein may be used as a ballasting system in emergency procedures where a blowout has occurred in a deep sea oil field.
- the aspects herein may be constructed to conform to one or more requirements of a subsea structure for applications such as ballasting or anchoring. Some examples include: hydraulic valve systems, drilling systems, and/or excavation equipment.
- a core anchor system unit 10 comprises a center access tube 12 centrally located and passing through a generally planar connecting structure 14 , also known as a tube sheet 14 .
- the center access tube 12 may define a flow channel through the tube sheet 14 or connect to a flow channel defined by the tube sheet 14 .
- the tube sheet 14 may be constructed from steel.
- the tube sheet 14 may be fabricated from steel plate of approximately 1-inch thickness and laminated to a further thickness as required, depending on the field conditions and the intended function of the core anchor system unit 10 .
- the center access tube 12 may be fabricated from a minimum of schedule 80 pipe. Larger diameters (e.g. above 48-inches) may be fabricated from penstock material. The particular pipe ratings may be selected to withstand field conditions with water depth being one of the considerations.
- a mud or excavation pump 48 may be mounted at the top of the center access tube 12 in order to excavate mud, silt, and/or sand from the underside of the tube sheet 14 .
- the excavation may cause the core anchor system 10 to become submerged in the ocean floor/substrate.
- the excavation pump 48 may be removed and replaced with a flange cap 46 .
- the tube sheet 14 may maintain the one or more water tubes 16 in rigid relation to one another.
- the hollow water tubes 16 may extend through and downward from the tube sheet 14 .
- the water tubes 16 may define longitudinal channels from a top of the tube sheet 14 to a bottom of the tube sheet 14 .
- the water tubes 16 may be located at precise locations in order to balance the tube sheet 14 .
- the water tubes 16 may be constructed from steel and may be seal-welded into the tube sheet 14 . Alternatively, the water tubes 16 may be fitted with collars and bolted into place.
- the water tubes 16 may be open at a top 20 and a bottom 30 of each of the water tubes 16 .
- one or more of the longitudinal channels of the water tubes 16 may be capped or closed by one or more shock absorbers 60 at the bottom 30 of the water tubes 16 as further described with reference to FIG. 5 below.
- the water tubes 16 may be fabricated from a minimum of schedule 80 pipe but may be adjusted based on field conditions.
- the tube sheet 14 may comprise one or more valve ports 22 fluidly coupled to additional flow channels 24 through the tube sheet 14 .
- the valve ports 22 may control flow of fluid through the additional flow channels 24 to remove water and/or mud from under the tube sheet 14 or to insert another material such as barite to displace the mud from under the tube sheet 14 .
- the flow channels 24 may extend to the bottom of the tube sheet 14 .
- Other aspects may have the flow channels 24 extending the entire length of the water tubes 16 or any length between the bottom of the tube sheet 14 and the length of the water tubes 16 .
- the length of the flow channels 24 may be optimized to control the consistency of the injected material.
- the flow channels 24 may be located closer to the skirt 18 than the water tubes 16 .
- the core anchor system unit 10 may have a skirt 18 .
- the skirt 18 may extend downward from the periphery of the tube sheet 14 .
- the skirt 18 is shown as a cutaway in order to show the interior of the skirt 18 .
- the skirt 18 may extend a portion of the water tubes 16 .
- the skirt 18 may extend to the bottom end 30 of the water tubes 16 (e.g. a full length of the water tubes 16 ).
- the skirt 18 may extend past the bottom end 30 of the water tubes 16 in order to facilitate a seal.
- the skirt 18 is not shown in order to more clearly demonstrate the interior features.
- the shock absorber 60 may be fabricated from a molded neoprene cylinder having an approximately 0.5-inch thickness.
- the shock absorber 60 may be attached to the bottom end 30 of the water tube 16 and form closed end 30 of the longitudinal channel.
- An upper pipe flange 32 and a lower pipe flange 34 may facilitate connection of the shock absorbers 60 to the bottom ends 30 of the water tubes 16 .
- the upper pipe flange 32 may be welded to the bottom of each water tube 16 and may be approximately 6 -inches in diameter.
- the cylindrical portion of the shock absorber 60 may be sandwiched between the two flanges 32 and 34 forming a water tight space at the very bottom of each water tube 16 .
- the shock absorbers 60 may comprise an outer housing 36 .
- a flexible wall 38 may separate an air chamber 40 within the housing 36 from seawater admitted through an opening 42 .
- the flexible wall 38 may take the form of the bottom 30 of the neoprene cylinder.
- the air chamber 40 may provide a cavity for expansion of the neoprene cylinder.
- the neoprene cylinder may be suitable for pressures in excess of 20,000 PSI.
- the shock absorber 60 may be placed on the water tubes 16 when the core unit 10 functions as a mooring device for a vessel or structure floating on the ocean surface and subjected to energy created through wave action. If a lateral or vertical force is applied to the core unit 10 (e.g. through severe wave action), the core unit 10 may undergo a jarring effect against the water column. The shock absorber 60 may dissipate the energy by having the air and neoprene compress without causing damage.
- the flexible wall 38 of the shock absorber 60 may be selected to be of a stiffness such that the shock absorber 60 may be moved by pressures encountered when deployed but may not fully collapse the air chamber 40 at an intended depth of use.
- the pressure of the overlying water on the flexible wall 38 of the shock absorber 60 may act to resist changes in attitude of the core anchor system unit 10 and exposed to the overlying water through the longitudinal channels of the water tubes 16 . If the density of the substrate material surrounding the core unit 10 is inconsistent in density, the shock absorbers 60 may maintain the unit 10 in a vertical position while a lateral force is applied to the core unit 10 .
- the sealed cavity 40 may be at ambient sea level air pressure and may require a non-conductor coating to prevent condensation in the air chamber 40 .
- FIGS. 6 and 7 depict the core anchor system unit 10 having no reinforcement.
- a pipe flange 44 may be the same diameter as the center access tube 12 and may be fitted and welded to an end of the center access tube 12 .
- a collar may be welded to the center access tube 12 and the collar may be bolted to the tube sheet.
- a flange cover 46 may be secured to a top of the pipe flange 44 when no other equipment may be attached to the pipe flange 44 .
- a size of the pipe flange 44 may be determined based on the intended function of the core anchor system unit 10 .
- a particular use of the core anchor system unit 10 may determine whether or not the flange cover 46 is required, such as when the core anchor system unit 10 serves as an anchor as mud may be added to the center access tube 12 to extrude water from the skirt 18 .
- the pipe flange 44 may accommodate securing a pump 48 having a capacity to pump heavy mud, silt, and/or sand.
- the pump 48 may form part of a suction element by being secured to the pipe flange 44 .
- the flange cover 46 may not be required when the core anchor system unit 10 acts as a drilling template or as a second layer of safety above a blowout preventer on an oil well.
- the unit 10 and center tube 12 may be large enough to accommodate a superstructure which would, in turn, may support a hydraulically operated knife gate valve with the capacity to sever steel.
- the center access tube 12 may extend downward to a point where the tube 12 may form a seal in the substrate.
- the diameter of the tube 12 may be large enough to accommodate a standard riser pipe. The entire structure may be locked in place by the weight of the above water column.
- the core anchor system unit 10 When the core anchor system unit 10 is deployed having the pump 48 , the core anchor system unit 10 may be connected by one or more hydraulic lines 54 to a hydraulic manifold system 52 .
- the hydraulic manifold system 52 may be situated either on board a surface vessel or may be placed on the bed, bottom, substrate, or floor 50 of a body of water, such as the sea, ocean, river or lake. The particular arrangement may be selected based on the field conditions and the particular use of the core anchor system unit 10 .
- the hydraulic manifold system 52 may be charged from a single source (not shown) located onboard a surface vessel (not shown). Hydraulic fluid may be directed under pressure to the core anchor system unit 10 to a point where the hydraulic fluid may open or close one of the individual valve ports 22 or power a motor (not shown) of the pump 48 .
- the hydraulic pump 48 and the valve ports 22 may be employed in the course of submerging the core anchor system unit 10 in the floor 50 and injecting mud. Once the core anchor system unit 10 is in position, the hydraulic manifold system 52 and the pump 48 may be removed to be used on another core anchor system unit 10 . If the core anchor system 10 is to be removed, the hydraulic manifold system 52 and the pump may be reattached to the core anchor system unit 10 and water may be pumped below the tube sheet 14 .
- the flange cover 46 may comprise two valve ports 22 .
- One port 22 may have a check valve between approximately 2-inches to 4-inches in diameter.
- the other port 22 may have a small gate valve of the same size. Both valves may facilitate the injection of barite mud and/or the extruding of water.
- These gate valves 22 may be operated mechanically by remotely operated vehicles (ROVs).
- the a core anchor system unit 10 may comprise attachments to accommodate a remote-operated vehicle (ROV) attached in a similar manner as the flange cover 46 shown in FIG. 6 .
- the ROV may, in turn, be equipped with a hydraulic mud pump, motor, and/or hydraulic reservoir.
- the ROV system may be self-contained and may require few mechanical attachments to the ocean surface.
- the gate valves 22 may comprise hydraulic knife-gate valves having the capacity to sever a drilling pipe (not shown).
- one hydraulic knife gate may be used to sever a defective pipe portion.
- the dimensions of this valve may be approximately 5-feet to 6-feet in diameter and may weight approximately 1000-lbs or more.
- the core anchor system unit 10 may be submerged in order to rest on the ocean floor.
- the anchor system unit 10 may be suspended to deploy and/or retrieve the anchor system unit 10 using the center access tube 12 .
- the center access tube 12 may be used to provide suction or injection of material to assist in sinking or raising the anchor system unit 10 into or from a substrate 50 of an ocean, a river, and/or a lake.
- the center access tube 12 may provide both a suspension element and a suction element.
- the excavation pump 48 may then be enabled to pump water, mud, silt, sand, and/or other material from the ocean floor through the center access tube 12 .
- a buoyancy of the core anchor system unit 10 may be moved to a lower position and one or more hydrostatic forces push the tubes 16 into the ocean floor.
- the stability of the unit 10 may be maintained by the hydrostatic force.
- An excavation of the mud, silt, and/or sand may cause the core anchor system unit 10 to become completely submerged in the substrate 50 .
- the excavation pump 48 may be removed and the center access tube 12 may be capped.
- the flange cover 46 may be fastened to the center access tube 12 of the core anchor system unit 10 after being submerged in the substrate 50 .
- the flange cover 46 may be fitted with two valve ports 22 , a check valve, and a gate valve.
- the gate valve allows dense mud to be pumped into the center tube 12 while the check valve allows water to be forced out of the capped access of the center access tube 12 as gate valve fills with the injected mud (e.g. barite).
- the unit 10 may be positioned vertically.
- the unit 10 may be submerged to a depth in the ocean substrate where an aggregate material of the ocean floor may be compacted and becoming solidified. This process involves no pounding of piles in any part of the deployment process.
- the top of the unit 10 may be submerged in mud, sand, or a combination of both mud and sand.
- the core anchor system unit 10 displaces the water by volume and therefore, the core anchor system 10 may experience buoyancy on an underside surface area of the tube sheet 14 and the skirt 18 .
- each water tube 16 extending below the tube sheet 14 lowers a center of gravity of the anchor system unit 10 .
- a portion of the underside surface area of the tube sheet 14 may be transferred down deep into compacted substrate material of the ocean.
- the buoyancy may have a lesser effect on the portion of the core anchor system 10 remaining at the surface of the substrate.
- the water tubes 16 may leave a small water-filled cavity on the underside of the tube sheet 14 , between the outer walls of the water tubes 16 and the skirt 18 .
- the remaining water present underneath the skirt 18 may be extruded through check valves by injecting fine ground heavy mud (e.g. barite) underneath the skirt 18 .
- fine ground heavy mud e.g. barite
- material with a higher density than the naturally deposited substrate material may be injected along an interior wall of the skirt 18 using the flow channels 24 .
- water may be forced out from underneath the skirt 18 using one or more check valves.
- a continuity of the water column may be interrupted sufficiently so as to cause a pressure imbalance which would in turn, lock the core unit 10 and any attached superstructure in place.
- the injected material e.g. barite, may be mixed with water only to a degree which may produce a viscosity to facilitate pumping or mixed with water only to a consistency which would permit pumping.
- the process may be reversed to remove the core anchor system unit 10 .
- the buoyancy may be restored by injecting water through the flow channels 24 .
- the core anchor system unit 10 may comprise a stabilizing reinforcement structure 800 .
- One or more ribs 802 may be fastened to the exterior of the skirt 18 .
- the ribs 802 comprise rectangular steel sheets welded along one edge generally perpendicular to the circumference of the skirt 18 .
- the ribs 802 extend the entire length of the skirt 18 .
- the stabilizing reinforcement structure 800 provides a reinforcement and stabilizing effect.
- a mooring unit 10 may be deployed at a depth of approximately 1-km and having a 35-feet height in order to reach the compacted substrate material.
- the skirt 18 needs to be approximately 35-feet in height in order to reach down to compacted substrate material.
- the tube sheet 14 may have a diameter of at least 25-feet.
- the hydrostatic pressure at a 1-km depth may be over approximately 1450-lbs per sq. inch.
- the reinforcement structure 800 allows for the unit 10 having a small calculated, diameter tube sheet 14 , while having an overall diameter that may be stable for the desired height of the unit 10 .
- the stabilizing reinforcement structure 800 may also permit the core anchor system unit 10 to remain stable as the barite is pumped into the core anchor system unit 10 .
- the reinforcement structure 800 may resist lateral pressure and/or collapse while the pressure inside the unit 10 is neutral or above neutral during mud injection and water removal.
- the stabilizing reinforcement structure 800 may support the anchor system unit 10 if the continuity of the water column is interrupted before the mud is sufficiently pressurized and compacted.
- the reinforcement structure 800 may also support the anchor system unit 10 while the mud compacts slowly as the mud settles due to gravity. The reinforcement structure increases the surface area in order to produce additional friction to resist lateral motion during suction.
- a strengthening flange 804 may be welded to the rib 802 .
- the strengthening flange 804 may minimize listing of the core anchor system unit 10 .
- the flange 804 may be curved with a radius of curvature similar to that of the skirt 18 and may extend the length of the skirt 18 .
- the flange 804 may be centrally attached to the edge of the rib 802 .
- the flange 804 may be integrally formed from the rib 802 by bending the edge of the rib 802 .
- One or more rings 806 may be welded to the flanges 804 .
- the rings may have a radius of curvature similar to that of the skirt 18 .
- three rings 806 are present with one on each end of the core anchor system unit 10 and one centrally located along the unit 10 .
- the three rings 806 enable material surrounding reinforcement structure 800 to flow toward the perimeter of the core unit 10 and tighten around the skirt 18 of the unit 10 .
- the center access tube 12 may extend below the tube sheet 14 .
- the center access tube 12 may extend to the bottom end of the water tubes 16 or to the level of the bottom of a skirt or shell casing 18 for aspects having a skirt 18 .
- shock absorbers 60 shown herein demonstrate a rounded housing 36
- other aspects may have different shaped housings 36 to assist in penetration of the water tubes 16 into the mud.
- a suspension element (not shown) may deploy and/or retrieve the anchor system unit 10 .
- the conventional suction anchor having dimensions of 30-feet in height and a diameter of 20-feet provides approximately 3786 square feet of surface area which would produce suction and friction between the anchor and the surrounding ocean substrate.
- the core anchor system unit 10 may have a surface area of 5652 square feet (excluding outer stabilizers and reinforcement) providing friction and suction at the interface between the unit 10 and the ocean substrate.
- the additional surface area may provide suction and friction may be 1884 square feet.
- the core anchor system unit 10 may only be submerged only to a point in the substrate where the aggregate material is sufficiently compacted in order to form a seal by injecting finely ground barite mud.
- the a core anchor system unit 10 may permit a number of structures to be attached, separate and apart from simple mooring lines. For example, several core units 10 may be held together by a superstructure to form a secure platform placed above or on the mud-filled substrate. In one example, the core units 10 may support a wind turbine that may be erected with minimal environmental impact in a cost effective manner.
- aspects herein describe a generally cylindrical core anchor system unit 10
- other aspects may comprise different shapes, such as for example, a rectangular prism.
Abstract
An anchoring system installed on a bottom of a body of water. The anchoring system has a tube sheet with an access tube defining a flow channel therethrough. One or more water tubes pass through the tube sheet. Each of the water tubes defining a longitudinal channel through the tube sheet. Each longitudinal channel has an open end at the top side and a closed end below the bottom side. A plurality of flow channels pass through the tube sheet. A skirt extends from the bottom of the tube sheet and defines a volume within the skirt encompassing at least a portion of the water tubes and the flow channels. A shock absorber is coupled to the closed end of at least one of the plurality of water tubes. The anchoring system is installed using negative pressure and extracted using positive pressure.
Description
- This invention is in the field of anchoring systems. In particular, the invention relates to submerged anchoring systems and methods.
- There is a need for anchoring systems to provide anchoring in soft ocean floors. A variety of tools are known, some of which rely upon suction to hold an anchor in the sea floor. For example as disclosed in US Publication No. 2012/0024535 discloses underwater wellhead closure systems that include a template having first and second anchoring ports and that is secured to a floor of a body of water. A suction pile having a cylindrical body with a head portion and an open bottom is coupled to the first anchoring port, such that the suction pile provides additional hold down force to the template. The system also includes a suction cap coupled to the second anchoring port, and has a cylindrical body with an open bottom and a head portion having at least one suction pump.
- There is provided an anchoring system having plural water tubes, each water tube defining a longitudinal channel, each longitudinal channel having an open end and a closed end opposite to the open end, a connecting structure maintaining the plural water tubes in rigid relation to one another, and each water tube of the plural water tubes extending from the connecting structure at least in a first direction, the longitudinal channels extending in the first direction from the respective open ends to the respective closed ends.
- In various aspects, there may be included any one or more of the following features: the connecting structure may comprise a cap. There may be a skirt extending in the first direction from the cap, for example along the full length of the skirt. There may be a suction element and a suction flow channel through the cap defined by the suction element or defined by the cap and connected to the suction element. There may be an additional flow channel through the cap and a valve controlling flow through the additional flow channel. There may be a suspension element connected to the connecting structure. There may be respective walls at the closed ends of the longitudinal flow channels, the flexible walls comprising a material selected to withstand undersea pressure, and each flexible wall separating the respective longitudinal flow channel from a respective air chamber to maintain a pressure differential in use of the anchoring system.
- There is also provided a ballasting unit having a housing open at a first end, a flexible wall separating the first end of the housing from a second end to define an air chamber at the second end, the flexible wall comprising a material selected to withstand undersea pressure, and to maintain a pressure differential in use of the ballasting unit.
- According to an aspect, an anchoring system may be configured to be installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material. The anchoring system may comprise: a tube sheet that may have a top side and a bottom side; an access tube may define a flow channel through the tube sheet from the top side to the bottom side; and a plurality of water tubes may pass through the tube sheet. The anchoring system may be cylindrical.
- Each of the plurality of water tubes may define a longitudinal channel from the top side to the bottom side of the tube sheet. Each longitudinal channel may comprise an open end at the top side and a closed end below the bottom side. A plurality of flow channels may pass through the tube sheet from the top side to the bottom side. A skirt may extend from the bottom side of the tube sheet and may define a volume within the skirt below the tube sheet encompassing at least a portion of the water tubes and the flow channels.
- The anchoring system may further comprise a shock absorber that may be coupled to the closed end of at least one of the plurality of water tubes. The shock absorber may comprise an air chamber. The air chamber may comprise at least one flexible wall configured to withstand undersea pressure and may maintain a pressure differential between the longitudinal flow channel and the air chamber. The at least one flexible wall may comprise a neoprene material. A cylinder may have the at least one flexible wall closing the closed end longitudinal channel. The shock absorber may withstand pressures in excess of 20,000 PSI. The shock absorber may be rounded at a bottom end to facilitate penetration into the bottom material.
- The anchoring system may further comprise an excavation pump operatively coupled to the access tube on the top side of the tube sheet. The excavation pump may transfer at least a portion of the bottom material from the bottom side to the top side of the tube sheet.
- The anchoring system may further comprise at least one valve port fluidly coupled to the plurality of flow channels. The plurality of flow channels may be located near an edge of the tube sheet and an edge of the skirt. The at least one valve port may be configured to remove water, the bottom material, and a combination of water and the bottom material from the volume of the skirt. An injected material may be injected into the at least one valve port and deposited within the volume of the skirt. The injected material may comprise barite mud.
- The anchoring system may further comprise a reinforcement structure coupled to the skirt. The reinforcement structure may resist lateral motion and maintains the position of the skirt.
- According to an aspect, there is provided a method of installing an anchoring system on a bottom of a body of water, the bottom of the body of water being formed of a bottom material. The method may comprise submerging the anchoring system and lowering the anchoring system until a bottom of a skirt rests on the bottom of the body of water. The skirt may define an inner volume with the bottom of the body of water. The method may comprise pumping, using an excavation pump, the bottom material from the inner volume through an access tube to produce a negative pressure within the inner volume. The negative pressure may be configured to pull the anchoring system beneath the bottom of the body of water. The method may comprise continuing to pump the bottom material from the inner volume until the bottom of the skirt reaches a solid substrate. The method may comprise injecting a mud denser than the bottom material into the inner volume using one or more flow channels. The method may comprise dissipating lateral motion, vertical motion, and a combination of lateral and vertical motion of the anchoring system using a plurality of shock absorbers on a bottom end of a plurality of water tube within the skirt.
- The method may further comprise stabilizing the anchoring system with a reinforcement structure. The mud may comprise barite.
- According to an aspect, there is provide a method of removing an anchoring system installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material. The method may comprise providing suction to at least one flow channel to withdraw a mud denser than the bottom material from a skirt defining an inner volume of the anchoring system, the skirt in contact with a solid substrate of the body of water. The method may comprise pumping water through an access tube to produce a positive pressure within the inner volume of the anchoring system causing the skirt to lift from the solid substrate of the body of water. The method may comprise continuing to pump water into the inner volume until the anchoring system becomes free from the bottom of the body of water. The method may comprise lifting the anchoring system from the bottom of the body of water.
- While the invention is claimed in the concluding portions hereof, example embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
-
FIG. 1 is a perspective view of an anchoring system without a skirt; -
FIG. 2 is a side perspective view of the anchoring system with a skirt about an upper part of the anchoring system; -
FIG. 3 is a side perspective view of the anchoring system with the skirt extending further than the skirt shown inFIG. 2 ; -
FIG. 4 is a side perspective view of the anchoring system; -
FIG. 5 is a side view of a ballasting unit for the anchoring system; -
FIG. 6 shows the anchoring system with a flange connection for connecting to a pump to pump fluid from the unit, and a flange cover; -
FIG. 7 shows the anchoring system with pump and hydraulics on a bed or floor of a body of water; and -
FIG. 8 shows a stabilizing reinforcement structure for the anchoring system; and -
FIG. 9 is a top view of the anchoring system with the stabilizing reinforcement structure. - The aspects described herein may serve as a mooring system in areas of the ocean, rivers, and/or other bodies of water where poor anchorage or holding ground exists. In particular, the aspects herein may be particularly applicable to sandy or silt ocean floor such as the Gulf of Mexico. The aspects herein may be used as a ballasting system in emergency procedures where a blowout has occurred in a deep sea oil field. The aspects herein may be constructed to conform to one or more requirements of a subsea structure for applications such as ballasting or anchoring. Some examples include: hydraulic valve systems, drilling systems, and/or excavation equipment.
- As shown in
FIGS. 1-4 , a coreanchor system unit 10 comprises acenter access tube 12 centrally located and passing through a generally planar connectingstructure 14, also known as atube sheet 14. Thecenter access tube 12 may define a flow channel through thetube sheet 14 or connect to a flow channel defined by thetube sheet 14. In this aspect, thetube sheet 14 may be constructed from steel. Particularly, thetube sheet 14 may be fabricated from steel plate of approximately 1-inch thickness and laminated to a further thickness as required, depending on the field conditions and the intended function of the coreanchor system unit 10. Thecenter access tube 12 may be fabricated from a minimum of schedule 80 pipe. Larger diameters (e.g. above 48-inches) may be fabricated from penstock material. The particular pipe ratings may be selected to withstand field conditions with water depth being one of the considerations. - A mud or
excavation pump 48 may be mounted at the top of thecenter access tube 12 in order to excavate mud, silt, and/or sand from the underside of thetube sheet 14. The excavation may cause thecore anchor system 10 to become submerged in the ocean floor/substrate. When theanchor system unit 10 has reached a desired depth, theexcavation pump 48 may be removed and replaced with aflange cap 46. - The
tube sheet 14 may maintain the one ormore water tubes 16 in rigid relation to one another. Thehollow water tubes 16 may extend through and downward from thetube sheet 14. Thewater tubes 16 may define longitudinal channels from a top of thetube sheet 14 to a bottom of thetube sheet 14. Thewater tubes 16 may be located at precise locations in order to balance thetube sheet 14. Thewater tubes 16 may be constructed from steel and may be seal-welded into thetube sheet 14. Alternatively, thewater tubes 16 may be fitted with collars and bolted into place. - According to the aspect presented in
FIG. 1 , thewater tubes 16 may be open at a top 20 and a bottom 30 of each of thewater tubes 16. In another aspect shown inFIGS. 2-4 , one or more of the longitudinal channels of thewater tubes 16 may be capped or closed by one ormore shock absorbers 60 at the bottom 30 of thewater tubes 16 as further described with reference toFIG. 5 below. Thewater tubes 16 may be fabricated from a minimum of schedule 80 pipe but may be adjusted based on field conditions. - As seen in
FIGS. 1 and 4 , thetube sheet 14 may comprise one ormore valve ports 22 fluidly coupled toadditional flow channels 24 through thetube sheet 14. Thevalve ports 22 may control flow of fluid through theadditional flow channels 24 to remove water and/or mud from under thetube sheet 14 or to insert another material such as barite to displace the mud from under thetube sheet 14. According to this aspect, theflow channels 24 may extend to the bottom of thetube sheet 14. Other aspects may have theflow channels 24 extending the entire length of thewater tubes 16 or any length between the bottom of thetube sheet 14 and the length of thewater tubes 16. The length of theflow channels 24 may be optimized to control the consistency of the injected material. In some aspects, theflow channels 24 may be located closer to theskirt 18 than thewater tubes 16. - According to the aspects presented in
FIGS. 2 and 3 , the coreanchor system unit 10 may have askirt 18. InFIG. 2 , theskirt 18 may extend downward from the periphery of thetube sheet 14. InFIG. 2 , theskirt 18 is shown as a cutaway in order to show the interior of theskirt 18. InFIG. 3 , theskirt 18 may extend a portion of thewater tubes 16. In some aspects (not shown), theskirt 18 may extend to thebottom end 30 of the water tubes 16 (e.g. a full length of the water tubes 16). In some aspects, theskirt 18 may extend past thebottom end 30 of thewater tubes 16 in order to facilitate a seal. In the aspect presented inFIGS. 1 and 4 , theskirt 18 is not shown in order to more clearly demonstrate the interior features. - Turning to
FIG. 5 , ashock absorber 60 is shown. Theshock absorber 60 may be fabricated from a molded neoprene cylinder having an approximately 0.5-inch thickness. Theshock absorber 60 may be attached to thebottom end 30 of thewater tube 16 and form closedend 30 of the longitudinal channel. Anupper pipe flange 32 and alower pipe flange 34 may facilitate connection of theshock absorbers 60 to the bottom ends 30 of thewater tubes 16. Theupper pipe flange 32 may be welded to the bottom of eachwater tube 16 and may be approximately 6-inches in diameter. The cylindrical portion of theshock absorber 60 may be sandwiched between the twoflanges water tube 16. - The
shock absorbers 60 may comprise anouter housing 36. Aflexible wall 38 may separate anair chamber 40 within thehousing 36 from seawater admitted through anopening 42. Theflexible wall 38 may take the form of the bottom 30 of the neoprene cylinder. Theair chamber 40 may provide a cavity for expansion of the neoprene cylinder. The neoprene cylinder may be suitable for pressures in excess of 20,000 PSI. When theshock absorbers 60 cap the bottom ends 30 of thewater tubes 16, arounded housing 36 may aid penetration of thewater tubes 16 into the mud. - The
shock absorber 60 may be placed on thewater tubes 16 when thecore unit 10 functions as a mooring device for a vessel or structure floating on the ocean surface and subjected to energy created through wave action. If a lateral or vertical force is applied to the core unit 10 (e.g. through severe wave action), thecore unit 10 may undergo a jarring effect against the water column. Theshock absorber 60 may dissipate the energy by having the air and neoprene compress without causing damage. - The
flexible wall 38 of theshock absorber 60 may be selected to be of a stiffness such that theshock absorber 60 may be moved by pressures encountered when deployed but may not fully collapse theair chamber 40 at an intended depth of use. The pressure of the overlying water on theflexible wall 38 of theshock absorber 60 may act to resist changes in attitude of the coreanchor system unit 10 and exposed to the overlying water through the longitudinal channels of thewater tubes 16. If the density of the substrate material surrounding thecore unit 10 is inconsistent in density, theshock absorbers 60 may maintain theunit 10 in a vertical position while a lateral force is applied to thecore unit 10. The sealedcavity 40 may be at ambient sea level air pressure and may require a non-conductor coating to prevent condensation in theair chamber 40. -
FIGS. 6 and 7 depict the coreanchor system unit 10 having no reinforcement. Apipe flange 44 may be the same diameter as thecenter access tube 12 and may be fitted and welded to an end of thecenter access tube 12. In another aspect, a collar may be welded to thecenter access tube 12 and the collar may be bolted to the tube sheet. Aflange cover 46 may be secured to a top of thepipe flange 44 when no other equipment may be attached to thepipe flange 44. A size of thepipe flange 44 may be determined based on the intended function of the coreanchor system unit 10. A particular use of the coreanchor system unit 10 may determine whether or not theflange cover 46 is required, such as when the coreanchor system unit 10 serves as an anchor as mud may be added to thecenter access tube 12 to extrude water from theskirt 18. Thepipe flange 44 may accommodate securing apump 48 having a capacity to pump heavy mud, silt, and/or sand. Thepump 48 may form part of a suction element by being secured to thepipe flange 44. - In another aspect, the
flange cover 46 may not be required when the coreanchor system unit 10 acts as a drilling template or as a second layer of safety above a blowout preventer on an oil well. Theunit 10 andcenter tube 12 may be large enough to accommodate a superstructure which would, in turn, may support a hydraulically operated knife gate valve with the capacity to sever steel. Thecenter access tube 12 may extend downward to a point where thetube 12 may form a seal in the substrate. The diameter of thetube 12 may be large enough to accommodate a standard riser pipe. The entire structure may be locked in place by the weight of the above water column. - When the core
anchor system unit 10 is deployed having thepump 48, the coreanchor system unit 10 may be connected by one or morehydraulic lines 54 to ahydraulic manifold system 52. Thehydraulic manifold system 52 may be situated either on board a surface vessel or may be placed on the bed, bottom, substrate, orfloor 50 of a body of water, such as the sea, ocean, river or lake. The particular arrangement may be selected based on the field conditions and the particular use of the coreanchor system unit 10. Thehydraulic manifold system 52 may be charged from a single source (not shown) located onboard a surface vessel (not shown). Hydraulic fluid may be directed under pressure to the coreanchor system unit 10 to a point where the hydraulic fluid may open or close one of theindividual valve ports 22 or power a motor (not shown) of thepump 48. - The
hydraulic pump 48 and thevalve ports 22 may be employed in the course of submerging the coreanchor system unit 10 in thefloor 50 and injecting mud. Once the coreanchor system unit 10 is in position, thehydraulic manifold system 52 and thepump 48 may be removed to be used on another coreanchor system unit 10. If thecore anchor system 10 is to be removed, thehydraulic manifold system 52 and the pump may be reattached to the coreanchor system unit 10 and water may be pumped below thetube sheet 14. - According to some aspects, the
flange cover 46 may comprise twovalve ports 22. Oneport 22 may have a check valve between approximately 2-inches to 4-inches in diameter. Theother port 22 may have a small gate valve of the same size. Both valves may facilitate the injection of barite mud and/or the extruding of water. Thesegate valves 22 may be operated mechanically by remotely operated vehicles (ROVs). The a coreanchor system unit 10 may comprise attachments to accommodate a remote-operated vehicle (ROV) attached in a similar manner as theflange cover 46 shown inFIG. 6 . The ROV may, in turn, be equipped with a hydraulic mud pump, motor, and/or hydraulic reservoir. The ROV system may be self-contained and may require few mechanical attachments to the ocean surface. Thegate valves 22 may comprise hydraulic knife-gate valves having the capacity to sever a drilling pipe (not shown). - When the core
anchor system unit 10 is used as a blowout preventer, one hydraulic knife gate may be used to sever a defective pipe portion. The dimensions of this valve may be approximately 5-feet to 6-feet in diameter and may weight approximately 1000-lbs or more. - According to aspects herein, the core
anchor system unit 10 may be submerged in order to rest on the ocean floor. Theanchor system unit 10 may be suspended to deploy and/or retrieve theanchor system unit 10 using thecenter access tube 12. Thecenter access tube 12 may be used to provide suction or injection of material to assist in sinking or raising theanchor system unit 10 into or from asubstrate 50 of an ocean, a river, and/or a lake. Thecenter access tube 12 may provide both a suspension element and a suction element. - The
excavation pump 48 may then be enabled to pump water, mud, silt, sand, and/or other material from the ocean floor through thecenter access tube 12. By pumping this material through thecenter access tube 12, a buoyancy of the coreanchor system unit 10 may be moved to a lower position and one or more hydrostatic forces push thetubes 16 into the ocean floor. The stability of theunit 10 may be maintained by the hydrostatic force. An excavation of the mud, silt, and/or sand may cause the coreanchor system unit 10 to become completely submerged in thesubstrate 50. - Once the core
anchor system unit 10 has reached a desired depth, theexcavation pump 48 may be removed and thecenter access tube 12 may be capped. When deployed as a mooring device, theflange cover 46 may be fastened to thecenter access tube 12 of the coreanchor system unit 10 after being submerged in thesubstrate 50. Theflange cover 46 may be fitted with twovalve ports 22, a check valve, and a gate valve. The gate valve allows dense mud to be pumped into thecenter tube 12 while the check valve allows water to be forced out of the capped access of thecenter access tube 12 as gate valve fills with the injected mud (e.g. barite). - After the
unit 10 is pushed down to the desired depth, theunit 10 may be positioned vertically. Theunit 10 may be submerged to a depth in the ocean substrate where an aggregate material of the ocean floor may be compacted and becoming solidified. This process involves no pounding of piles in any part of the deployment process. In some aspects, the top of theunit 10 may be submerged in mud, sand, or a combination of both mud and sand. - The core
anchor system unit 10 displaces the water by volume and therefore, thecore anchor system 10 may experience buoyancy on an underside surface area of thetube sheet 14 and theskirt 18. In order to counteract this effect, eachwater tube 16 extending below thetube sheet 14 lowers a center of gravity of theanchor system unit 10. Also, a portion of the underside surface area of thetube sheet 14 may be transferred down deep into compacted substrate material of the ocean. By lowering the center of gravity and transferring the underside surface area to a deeper position, the buoyancy may have a lesser effect on the portion of thecore anchor system 10 remaining at the surface of the substrate. Thewater tubes 16 may leave a small water-filled cavity on the underside of thetube sheet 14, between the outer walls of thewater tubes 16 and theskirt 18. - When a seal could be formed underneath the
skirt 18 and the compacted ocean substrate, the remaining water present underneath theskirt 18 may be extruded through check valves by injecting fine ground heavy mud (e.g. barite) underneath theskirt 18. To remove a majority of the buoyancy effect and hold theanchor system unit 10 in place, material with a higher density than the naturally deposited substrate material may be injected along an interior wall of theskirt 18 using theflow channels 24. By injecting material with the higher density, water may be forced out from underneath theskirt 18 using one or more check valves. Through removal of the water under theskirt 18, a continuity of the water column may be interrupted sufficiently so as to cause a pressure imbalance which would in turn, lock thecore unit 10 and any attached superstructure in place. The injected material, e.g. barite, may be mixed with water only to a degree which may produce a viscosity to facilitate pumping or mixed with water only to a consistency which would permit pumping. - The process may be reversed to remove the core
anchor system unit 10. The buoyancy may be restored by injecting water through theflow channels 24. - Turning to
FIGS. 8 and 9 , the coreanchor system unit 10 may comprise a stabilizingreinforcement structure 800. One ormore ribs 802 may be fastened to the exterior of theskirt 18. In this aspect, theribs 802 comprise rectangular steel sheets welded along one edge generally perpendicular to the circumference of theskirt 18. In this aspect, theribs 802 extend the entire length of theskirt 18. - The stabilizing
reinforcement structure 800 provides a reinforcement and stabilizing effect. For example, amooring unit 10 may be deployed at a depth of approximately 1-km and having a 35-feet height in order to reach the compacted substrate material. In this case, theskirt 18 needs to be approximately 35-feet in height in order to reach down to compacted substrate material. For the sake of stability and considering the ocean environment, if theskirt 18 were to be 35 feet in height, thetube sheet 14 may have a diameter of at least 25-feet. The hydrostatic pressure at a 1-km depth may be over approximately 1450-lbs per sq. inch. The square footage of thetube sheet 14 combined with the added pressure caused by the transfer of portions of thetube sheet 14 by thewater tubes 16, may cause excessive total pressure exerted on theunit 10. In order to compensate for this excessive total pressure, thereinforcement structure 800 allows for theunit 10 having a small calculated,diameter tube sheet 14, while having an overall diameter that may be stable for the desired height of theunit 10. - The stabilizing
reinforcement structure 800 may also permit the coreanchor system unit 10 to remain stable as the barite is pumped into the coreanchor system unit 10. Thereinforcement structure 800 may resist lateral pressure and/or collapse while the pressure inside theunit 10 is neutral or above neutral during mud injection and water removal. For example, the stabilizingreinforcement structure 800 may support theanchor system unit 10 if the continuity of the water column is interrupted before the mud is sufficiently pressurized and compacted. Thereinforcement structure 800 may also support theanchor system unit 10 while the mud compacts slowly as the mud settles due to gravity. The reinforcement structure increases the surface area in order to produce additional friction to resist lateral motion during suction. - Along an edge opposite to the edge welded to the
skirt 18, a strengtheningflange 804 may be welded to therib 802. The strengtheningflange 804 may minimize listing of the coreanchor system unit 10. Theflange 804 may be curved with a radius of curvature similar to that of theskirt 18 and may extend the length of theskirt 18. In this aspect, theflange 804 may be centrally attached to the edge of therib 802. In other aspects, theflange 804 may be integrally formed from therib 802 by bending the edge of therib 802. - One or
more rings 806 may be welded to theflanges 804. The rings may have a radius of curvature similar to that of theskirt 18. In this aspect, threerings 806 are present with one on each end of the coreanchor system unit 10 and one centrally located along theunit 10. The threerings 806 enable material surroundingreinforcement structure 800 to flow toward the perimeter of thecore unit 10 and tighten around theskirt 18 of theunit 10. - Although the aspects shown herein demonstrate the
center access tube 12 not extending below thetube sheet 14, in other aspects, thecenter access tube 12 may extend below thetube sheet 14. For example, thecenter access tube 12 may extend to the bottom end of thewater tubes 16 or to the level of the bottom of a skirt orshell casing 18 for aspects having askirt 18. - Although the
shock absorbers 60 shown herein demonstrate arounded housing 36, other aspects may have different shapedhousings 36 to assist in penetration of thewater tubes 16 into the mud. - Although the aspects herein demonstrate using the
center access tube 12 for positioning the coreanchor system unit 10, other aspects may provide separate elements for positioning. For example, a suspension element (not shown) may deploy and/or retrieve theanchor system unit 10. - Although particular dimensions, reinforcements, and/or stabilizer requirements may be described herein, these attributes may be adjusted based on the ocean depth, field conditions, and/or an intended use of the core
anchor system unit 10. Although particular proportions may be demonstrated in the drawings, the proportions may be adjusted based on the ocean depth, field conditions, and/or the intended use of thecore anchor system 10. The aspects presented herein operate similar to conventional anchors with generally smaller dimensions. For example, conventional anchors have dimensions of between 6-20 meters in diameter and lengths of 30 meters or more. - For example, the conventional suction anchor having dimensions of 30-feet in height and a diameter of 20-feet provides approximately 3786 square feet of surface area which would produce suction and friction between the anchor and the surrounding ocean substrate. In an example aspect herein having the same overall volume and dimensions (e.g. height of 30 feet and a diameter of 20 feet) the core
anchor system unit 10 may have a surface area of 5652 square feet (excluding outer stabilizers and reinforcement) providing friction and suction at the interface between theunit 10 and the ocean substrate. When the surface area of thewater tubes 16 plus thecenter access tube 12 are calculated, the additional surface area may provide suction and friction may be 1884 square feet. - Additionally, conventional anchors may require complete submersion in the substrate. In the aspects herein, the core
anchor system unit 10 may only be submerged only to a point in the substrate where the aggregate material is sufficiently compacted in order to form a seal by injecting finely ground barite mud. - According to some aspects, the a core
anchor system unit 10 may permit a number of structures to be attached, separate and apart from simple mooring lines. For example,several core units 10 may be held together by a superstructure to form a secure platform placed above or on the mud-filled substrate. In one example, thecore units 10 may support a wind turbine that may be erected with minimal environmental impact in a cost effective manner. - Although the aspects herein describe a generally cylindrical core
anchor system unit 10, other aspects may comprise different shapes, such as for example, a rectangular prism. - Immaterial modifications may be made to the embodiments described here without departing from what is covered by the claims.
- In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite articles “a” and “an” before a claim feature do not exclude more than one of the feature being present. Each one of the individual features described here may be used in one or more embodiments and is not, by virtue only of being described here, to be construed as essential to all embodiments as defined by the claims.
- The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
Claims (20)
1. An anchoring system configured to be installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material, the anchoring system comprising:
a tube sheet having a top side and a bottom side;
an access tube defining a flow channel through the tube sheet from the top side to the bottom side;
a plurality of water tubes passing through the tube sheet, each of the plurality of water tubes defining a longitudinal channel from the top side to the bottom side of the tube sheet, each longitudinal channel comprises an open end at the top side and a closed end below the bottom side;
a plurality of flow channels through the tube sheet from the top side to the bottom side;
a skirt extending from the bottom side of the tube sheet and defining a volume within the skirt below the tube sheet encompassing at least a portion of the water tubes and the flow channels; and
a shock absorber coupled to the closed end of at least one of the plurality of water tubes.
2. The anchoring system according to claim 1 , wherein the shock absorber comprises an air chamber.
3. The anchoring system according to claim 2 , wherein the air chamber comprises at least one flexible wall configured to withstand undersea pressure and maintain a pressure differential between the longitudinal flow channel and the air chamber.
4. The anchoring system according to claim 3 , wherein the at least one flexible wall comprises a neoprene material.
5. The anchoring system according to claim 3 , further comprising a cylinder wherein the at least one flexible wall closes the closed end longitudinal channel.
6. The anchoring system according to claim 1 , wherein the shock absorber withstands pressures in excess of 20,000 PSI.
7. The anchoring system according to claim 1 , wherein the shock absorber is rounded at a bottom end to facilitate penetration into the bottom material.
8. The anchoring system according to claim 1 , further comprising an excavation pump operatively coupled to the access tube on the top side of the tube sheet, the excavation pump transferring at least a portion of the bottom material from the bottom side to the top side of the tube sheet.
9. The anchoring system according to claim 1 , further comprising at least one valve port fluidly coupled to the plurality of flow channels.
10. The anchoring system according to claim 9 , wherein the at least one valve port is configured to remove water, the bottom material, and a combination of water and the bottom material from the volume of the skirt.
11. The anchoring system according to claim 9 , wherein an injected material is injected into the at least one valve port and deposited within the volume of the skirt.
12. The anchoring system according to claim 11 , wherein the injected material comprises barite mud.
13. The anchoring system according to claim 1 , wherein the plurality of flow channels are located near an edge of the tube sheet and an edge of the skirt.
14. The anchoring system according to claim 1 , further comprising a reinforcement structure coupled to the skirt.
15. The anchoring system according to claim 14 , wherein the reinforcement structure resists lateral motion and maintains the position of the skirt.
16. The anchoring system according to claim 1 , wherein the anchoring system is cylindrical.
17. A method of installing an anchoring system on a bottom of a body of water, the bottom of the body of water being formed of a bottom material, the method comprises:
submerging the anchoring system and lowering the anchoring system until a bottom of a skirt rests on the bottom of the body of water, the skirt defining an inner volume with the bottom of the body of water;
pumping, using an excavation pump, the bottom material from the inner volume through an access tube to produce a negative pressure within the inner volume, the negative pressure configured to pull the anchoring system beneath the bottom of the body of water;
continuing to pump the bottom material from the inner volume until the bottom of the skirt reaches a solid substrate;
injecting a mud denser than the bottom material into the inner volume using one or more flow channels; and
dissipating lateral motion, vertical motion, and a combination of lateral and vertical motion of the anchoring system using a plurality of shock absorbers on a bottom end of a plurality of water tube within the skirt.
18. The method of claim 17 further comprises stabilizing the anchoring system with a reinforcement structure.
19. The method of claim 17 in which the mud comprises barite.
20. A method of removing an anchoring system installed on a bottom of a body of water, the bottom of the body of water being formed of a bottom material, the method comprises:
providing suction to at least one flow channel to withdraw a mud denser than the bottom material from a skirt defining an inner volume of the anchoring system, the skirt in contact with a solid substrate of the body of water;
pumping water through an access tube to produce a positive pressure within the inner volume of the anchoring system causing the skirt to lift from the solid substrate of the body of water;
continuing to pump water into the inner volume until the anchoring system becomes free from the bottom of the body of water; and
lifting the anchoring system from the bottom of the body of water.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/964,996 US20180245302A1 (en) | 2016-02-11 | 2018-04-27 | Anchoring system and method |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201662294290P | 2016-02-11 | 2016-02-11 | |
US15/429,768 US10024021B2 (en) | 2016-02-11 | 2017-02-10 | Anchoring system |
US15/964,996 US20180245302A1 (en) | 2016-02-11 | 2018-04-27 | Anchoring system and method |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/429,768 Continuation-In-Part US10024021B2 (en) | 2016-02-11 | 2017-02-10 | Anchoring system |
Publications (1)
Publication Number | Publication Date |
---|---|
US20180245302A1 true US20180245302A1 (en) | 2018-08-30 |
Family
ID=63245634
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/964,996 Abandoned US20180245302A1 (en) | 2016-02-11 | 2018-04-27 | Anchoring system and method |
Country Status (1)
Country | Link |
---|---|
US (1) | US20180245302A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112211790A (en) * | 2019-07-10 | 2021-01-12 | 北京金风科创风电设备有限公司 | Ground anchor device, inhaul cable tower, wind generating set and construction method |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110274503A1 (en) * | 2010-05-07 | 2011-11-10 | Chevron U.S.A. Inc. | Apparatus and method for securing subsea devices to a seabed |
US20120230773A1 (en) * | 2011-03-09 | 2012-09-13 | Keppel Offshore & Marine Technology Centre Pte Ltd. | Skirted Foundation For Penetrating Soft Material |
-
2018
- 2018-04-27 US US15/964,996 patent/US20180245302A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110274503A1 (en) * | 2010-05-07 | 2011-11-10 | Chevron U.S.A. Inc. | Apparatus and method for securing subsea devices to a seabed |
US20120230773A1 (en) * | 2011-03-09 | 2012-09-13 | Keppel Offshore & Marine Technology Centre Pte Ltd. | Skirted Foundation For Penetrating Soft Material |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112211790A (en) * | 2019-07-10 | 2021-01-12 | 北京金风科创风电设备有限公司 | Ground anchor device, inhaul cable tower, wind generating set and construction method |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4425055A (en) | Two-section arctic drilling structure | |
CA1235913A (en) | System for driving open end pipe piles on the ocean floor using pneumatic evacuation and existing hydrostatic pressure | |
US4405258A (en) | Method for containing oil and/or gas within a blow-out cover dome | |
US4098333A (en) | Marine production riser system | |
US3859806A (en) | Offshore platform | |
US3698198A (en) | Deep-water drilling, production and storage system | |
US9758941B2 (en) | Offshore tower for drilling and/or production | |
US3535884A (en) | Offshore drilling and production structure | |
US3380256A (en) | Underwater drilling installation and method of construction | |
WO2014114235A1 (en) | Suction-type pile leg, offshore caisson, and seabed-fixed offshore platform | |
US3976021A (en) | Installation of vertically moored platform | |
EP0039699A1 (en) | Method and column for collection and separation of oil, gas and water from blowing wells at the sea bed | |
EA002582B1 (en) | Offshore caisson | |
CN103270221B (en) | For drilling and/or exploit offshore structure and the method thereof of submarine well | |
US4626136A (en) | Pressure balanced buoyant tether for subsea use | |
US2699042A (en) | Portable marine foundation for drilling rigs and method of operation | |
US3552903A (en) | Subsea production satellite | |
US6203248B1 (en) | Sliding-resistant bottom-founded offshore structures | |
US3657895A (en) | Offshore platform | |
US2865179A (en) | Offshore drilling structure | |
US4069681A (en) | Offshore structure for deltaic substrates | |
US20180245302A1 (en) | Anchoring system and method | |
US4695201A (en) | Removable bottom founded structure | |
US3396544A (en) | Storage tank fixed on the ocean bottom and method of installation | |
MX2010005485A (en) | Self-standing riser system having multiple buoyancy chambers. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |