Abstract: Various embodiments relate to a method and a seabed supported base structure for providing a shallow water drilling terminal, where a prefabricated floating seabed substructure is towed to site, ballasted to rest on the seabed and/or piled to the seabed forming a seabed foundation. The seabed supported base structure is provided with at least one cantilevered unit with openings for drilling of wells, projecting sideways out from the exterior side of a vertical wall, terminated above sea level. A prefabricated floating drilling module provided with an outrigger with sidewise movable drilling device is towed to the site, guided into the seabed substructure through an opening in the wall structure at the periphery of the base structure, ballasted and mated onto the base structure, whereupon wells are drilled from a drilling gear. Upon completed drilling and operation of the wells, the drilling unit is removed and substituted by a production unit.

Abstract: Process for installing an offshore tower, specifically a substructure, which basically comprises the following steps: a) dry manufacturing a foundation comprising a block (1, 1?) basically made of concrete and dry manufacturing a base section (25) of a shaft (2); b) applying said base section to said foundation block, forming a unit called the “starting unit”; c) moving said starting unit to the installation point of said substructure; and d) actuating in a controlled manner, first ballast valve means in such a manner that said starting unit sinks until resting on the seabed; having placed said foundation block or said starting unit in the body of water where the installation point said substructure is located.

Abstract: A subsea system for installing, suspending and removing underwater equipment below the surface of the sea is provided. The subsea system includes a landing base module for landing and positioning underwater equipment thereupon, the landing base module comprising a base member and a first buoyancy system; and a second buoyancy system for affixing to the underwater equipment, the second buoyancy system having sufficient buoyancy to float the underwater equipment toward the surface of the sea when detached from the landing base module, wherein the underwater equipment includes a ballast system structured and arranged to permit the underwater equipment to be lowered onto the landing base module. A method for installing, suspending and removing underwater equipment below the surface of the sea and a kit of parts are also provided.

Abstract: It includes at least one platform defining a plane, first and second sets of complementary coupling elements associated with the tower section and the platform respectively, and arranged in levels. In a first relative position of the sets of coupling elements, the platform is allowed to pass, in a substantially horizontal position, through different levels of sets of coupling elements and in a second relative position of the sets of coupling elements, the platform rests with its second set of coupling elements on a first set of coupling elements of one given level. A device for moving the platform may be provided for fitting it inside the tower section. The first or the second set of coupling elements in different levels are aligned along a longitudinal direction inside the tower section.

Abstract: A system for hydraulically fracturing an underground formation in an oil or gas well to extract oil or gas from the formation, the oil or gas well having a wellbore that permits passage of fluid from the wellbore into the formation. The system includes a plurality of electric pumps fluidly connected to the well, and configured to pump fluid into the wellbore at high pressure so that the fluid passes from the wellbore into the and fractures the formation. The system can also include a plurality of natural gas powered generators electrically connected to the plurality of electric pumps to provide electrical power to the pumps.

Abstract: A barge has been designed to function in a four-season environment with a plurality of configurable, peripheral bays (bays) that support sustainable energy capture devices (devices). The barge is round with bays that curve inward, opposite the barge's curvature, and where devices can be placed. The bays allow the devices to be removed for maintenance by support ships. The barge is buoyant and floats independently of the devices in each bay. The barge is hollow and its entire circumference can be traversed by the crew. A central platform is contained within the barge by cables that may have wave energy capture mechanisms installed. The central platform and can be accessed by the crew through one or multiple floating walkways. Devices installed at the bays will float independently of the barge and may have wave energy capture mechanisms on them at the bay-device interface.

Abstract: A new jacket design method is disclosed, especially for deepwater water heavy jacket applications. The method utilizes a special type of air bags, called Ship Launching Air Bags (SLAB), to provide low cost temporary buoyancy used for jacket installation purpose only. A designer only needs to satisfy the jacket stiffness for the resistance of environmental and gravity loads without the consideration of jacket reserve buoyancy. The required jacket reserve buoyancy could be increased with the utilization of temporally attached SLABs during the jacket installation.

Abstract: A single heavy lift system is made of modular units, each of which has a pair of supporting legs carrying a transverse beam therebetween. The beam is engaged to the supporting legs through jackup units that allow the transverse beams of several modular units move in unison and thus increase lifting capacity of the system. The modular units can be formed as modular, self-propelled units, transported to the site, where the lifting task is to be performed if necessary. The system can be positioned in a dry dock or offshore.

Abstract: Concrete silo for offshore drilling and production operations includes a reinforced concrete foundation secured at the seabed by steel piles and steel anchors embedded into the seabed. An exterior vertical reinforced concrete wall is supported by the foundation. An interior vertical reinforced concrete wall is supported by the foundation and houses a central cell. A series of radial shear walls extend between the exterior concrete wall and the interior concrete wall to form a series of perimeter cells. A roof and series of horizontally extending service platforms are supported off of the outer concrete wall and the interior concrete wall. A series of vertical well casings extend through the concrete foundation and down into the seabed for drilling operations.

Abstract: Embodiments of gravity base structures are disclosed that comprise first and second elongated base sections separated by an open region and configured to support the on-bottom weight of the structure on a seabed, and an upper section positioned above the open region and configured to extend at least partially above the water surface to support topside structures. Some embodiments further comprise first and second inclined sections coupling the base sections to the upper section. Some embodiments comprise a skirt structure below the base sections for facilitating engagement with the seabed. Some embodiments comprise selectively fillable internal fluid chambers to facilitate raising and lowering the structure in a sea and relocating the structure.

Abstract: A structure for a tidal flow energy generation system is fabricated from tubular framework having tubular modules with mounts for respective tidal flow turbine nacelles. The node modules include tubular limbs extending in transverse directions and elongate tubes and provided to interconnect with the tube limbs of the node modules. The structure can be pre-fabricated and transported to a location for deployment. The structure can be deployed by means of hovering the assembled structure to the seabed, for example by means of flooding the structure.

Abstract: Embodiments of gravity base structures are disclosed that comprise first and second elongated base sections separated by an open region and configured to support the on-bottom weight of the structure on a seabed, and an upper section positioned above the open region and configured to extend at least partially above the water surface to support topside structures. Some embodiments further comprise first and second inclined sections coupling the base sections to the upper section. Some embodiments comprise a skirt structure below the base sections for facilitating engagement with the seabed. Some embodiments comprise selectively fillable internal fluid chambers to facilitate raising and lowering the structure in a sea and relocating the structure.

Abstract: Embodiments of gravity base structures are disclosed that comprise first and second elongated base sections separated by an open region and configured to support the on-bottom weight of the structure and be supported by the floor of the body of water, and an upper section positioned above the open region and configured to extend at least partially above the water surface to support topside structures. Some embodiments further comprise first and second inclined sections coupling the base sections to the upper section.

Abstract: The disclosure provides an offshore platform and related method, having: a floating structure, a truss assembly coupled to the floating structure, and a heave plate coupled to the truss assembly. The floating structure includes a pontoon adapted to be disposed at least partially below a surface of water in which the offshore platform is disposed; and at least three vertically extending columns coupled to the pontoon, the columns having a larger lateral dimension than the pontoon coupled to the column, creating a pontoon offset portion. The truss assembly includes at least three separated walls of trusses slidably coupled to the columns, each truss wall having at least two vertically disposed truss legs, each truss leg being slidably coupled to a column at the pontoon offset portion independently from a truss leg of an adjacent wall; and cross-bracing between the truss legs of each of the truss walls.

Abstract: A complementary locking system for locking legs to the deck of a jack-up offshore drilling platform is disabled. The system includes at each leg, at least one assembly comprising plates forming two counter-racks that engage with a leg rack and, on one side of the plates, at least one internal element for connecting the internal edges of the plates, at least one external element for connecting the external edges of the plates and at least one intermediate member for connecting said at least one internal element to said at least one external element. Methods of installing said complementary locking system on the legs of a jack-up offshore drilling platform are also disclosed.

Abstract: The present invention relates to a mobile offshore oil drilling and production platform (10) that allows a field operator to cope with uncertainty and economically develop a small or marginal oil filed typically located in a remote location. More particularly, the invention relates to a versatile platform which includes a hull (12) extending above the level of sea to house hydrocarbon extracting and scale up or scale down hydrocarbon processing system modules and equipment with provisions to drill new wells and work-overs using modular portable vertical drilling rigs or conventional rigs, connected to a mat acting as the foundation resting on the seabed which may or may not incorporate storage, using tubular legs, and provision to even abandon the field with minimal costs and disruption. The present invention also relates to a method of installing and de-installing the oil drilling and production platform (10).

Abstract: A method and system for attaching a TLP to its tendons using pull-down lines to rapidly submerge the hull to installation draft while compensating for inherent hull instability during submergence and to provide motion arrest and aid in station keeping. The system includes tensioning devices mounted on the TLP, usually one for each tendon. Each tensioning device is equipped with a pull-down line which is connected to the corresponding tendon. The TLP hull is submerged to lock-off draft by applying tensions to the pull-down lines connected to the top of the tensions, or by a combination of applying tensions to the pull-down lines and ballasting the hull. As the tensioners take in pull-down line, the hull submerges, i.e. the draft increases.

Abstract: A drilling rig, in particular for the offshore industry, in the form of a jack-up platform on which a cantilever is mounted so as to be movable at least substantially horizontally and in a first direction, with the cantilever projecting more or less outside the jack-up platform. On the cantilever a drilling platform is present, which drilling platform is movable relative to the jack-up platform in a second direction, different herefrom. This drilling platform is fixedly mounted on the cantilever while the latter is movable relative to the jack-up platform in both abovesaid directions.

Abstract: Improvements to a ring pontoon semisubmersible vessel. The centerlines of the corner columns ar displaced with respect to the axial centerlines of the forward and aft portions of the ring pontoon. Additionally, the centerlines of the corner columns may be displaced with respect to the axial centerlines of the starboard and port portions of the ring pontoon. The superstructure deck may be supported by radial braces extending from the ring pontoon to locations on the superstructure deck which are inward of the ring pontoon.

Abstract: A deep water platform, suitable for use as a hydrocarbon exploration or production facility in very deep offshore waters, and a method of constructing the same are shown. The platform is positioned on top of a buoyant leg structure. During normal drilling operations the platform is anchored by a gravity base tethered with pre-tensioned cables to the buoyant leg structure. According to the invention, the gravity base is retractable to permit the platform to be moved from site to site within a drilling region. Long distance relocation is also possible by retracting the gravity base, disassembling the platform, transporting the component parts, and reassembling the rig in a new location.

Abstract: A jack-up rig includes a cantilever beam assembly and a drilling module is mounted on the cantilever beam assembly. The jack-up rig also includes means for moving the cantilever beam assembly from the storage position to extended positions wherein a rearward end of the cantilever beam assembly is extended from the jack-up rig. The fixed platform comprises a fixed platform support structure having a drilling module support surface and a beam opening. The jack-up rig is positioned near the fixed platform with the cantilever beam assembly generally aligned with the beam opening in the fixed platform support structure. The cantilever beam assembly then is extended through a portion of the beam opening to an extended position wherein the drilling module is supported on the cantilever beam assembly a distance generally above the drilling module support surface. The jack-up rig then is lowered to a position wherein the drilling module is supported on the fixed platform support structure.

Abstract: A submersible production storage barge and method for transporting and installing a jack-up rig in a body of water has the submersible production storage barge releasably secured to a jack-up rig while the jack-up rig and submersible production storage barge are towed as a unit to the desired offshore location.

Abstract: A node intersection between circular columns and pontoon members at a tendon-moored semisubmersible offshore platform. The pontoon members have a box shape, defined by vertical side walls, a horizontal deck and a horizontal bottom skin, joined together into a foursided frame, via the columns. The node intersection comprises vertical bulkheads within the lower ends of the columns, forming internally intersecting continuations of the vertical sidewalls.

Abstract: A jacket tower structure for use in deep water which includes a plurality of tapering jacket sections adapted to be nested, each section including at least three jacket legs. The base and lower jacket sections include cylindrical legs interconnected by box section bracing, the upper jacket sections including cylindrical bracing. The box section bracing is connected to the legs by a unique joint for transmitting stresses to the legs. The box section bracing is floodable for equilizing hydrostatic pressure during and upon installations. Certain transverse box section bracing at ends of adjacent jacket sections include intermediate connection projections for welding during joining of adjacent jacket sections. The cylindrical legs include a plurality of water tight compartments of selected volume, each compartment having one or more check valves for admitting water into the compartments when external water pressure exceeds air pressurization of the compartments.

Abstract: A mobile sea barge having a unitary lower hull which has sufficient buoyancy to float the entire barge, an upper hull spaced from the lower hull by a single, centrally-positioned, vertical member, and a movable stabilizing hull arranged about the central support member for controlled movement between the upper and lower hulls is provided. Controlled movement of the stabilizing hull permits the operational modes of submerging and emerging of the lower hull into or from a bottom-founded gravity-forced mode from which drilling operations can be carried out. In the bottom-founded mode on the sea floor the barge functions as a gravity platform. Movement of the stabilizing hull is provided by a plurality of jacking legs and jacking units which constitute the control devices. The barge can be quickly switched between the surface-floating and the gravity-forced, bottom-founded modes. Controlled vertical descent to the sea floor is provided by the static stability of the stabilizing hull.

Abstract: The platform comprises an annular truncated cone of concrete which constitutes the main resistant element of the platform and is designed to take the thrust of ice, and a cylindrical steel part housed inside the annular truncated cone. Watertight passages parallel to the generatrices of the cylindrical wall are provided to house piles in the peripheral ring, close to the wall. A watertight passage well is provided in the cylindrical steel part for the passage of the drill pipes. A circular running track is provided for gantry cranes used for piles handling. The platform has two drilling rigs placed on one half of the platform and able to work simultaneously.

Abstract: The procedure for draining off shallow gas from the seabed and arrangement for execution of the procedure, whereby through the upper sedimentary layer is placed a system of vertical drainage piles (2) for gas around the site in question for location of a construction on the seabed or along a pipeline route on the seabed.The arrangement includes principally a base plate (1) with a central hole for acceptance of a drainage pile (2) after the base plate (1) has been placed on the seabed.

Abstract: An offshore construction in which a floatable platform is supported through raisable and lowerable support legs directly or indirectly on the sea bed. At least two cable winches for each support leg are arranged as lifting equipment on the platform. One cable winch is connected through a single cable line with the lower end of a support leg. The other cable winch displays a multiple cable line guided around two pulley blocks. One of these pulley blocks is arranged on the support leg. In order to be able to employ the lifting equipment even in the case of great support leg lengths, the other pulley block is arranged on a ring. This ring surrounds the support leg and is detachably connected through a locking device with the platform.

Abstract: A stable offshore platform for surface or undersea work is provided by connecting a semi-submersible trailer unit with a workboat. Preferably, two columns of the trailer are joined by a beam member or truss, and this assembly is linked to the workboat via a truss-like trailer tongue with a ball swivel joint. When in transit, the semi-submersible unit is deballasted to a shallow draft condition and towed by the workboat.

Abstract: A mobile offshore platform and method of fabrication are disclosed. The platform features a deck member, a base member, leg structures interconnecting the two members, and means for varying the distance between the members. The leg structures are secured to the base and are preferably spaced around the periphery of the work area at the vertices of a regular polygon to provide a deck member having a large, substantially obstruction-free, work area. The legs are also connected to the base member to provide a force resistant to vertical flexing of the base member, and to distribute more uniformly the loading of the base member. The base member is adapted to store petroleum products. A multi-tiered embodiment for deep water work is also disclosed.

Abstract: The invention relates to an offshore, gravity base, jack-up platform comprising a deck, a gravity base and one or more legs interconnecting the deck and base. The gravity base comprises a generally polygonal shaped, monolithic hull structure with reaction members extending downwardly from the hull to penetrate the waterbed and react to vertical and lateral loads imposed upon the platform while maintaining the gravity hull in a posture elevated above the surface of the waterbed.A method aspect of the invention includes the steps of towing a gravity base, jack-up platform, as a unit, to a preselected offshore site floating upon the gravity hull. During the towing operation, the deck is mounted adjacent the gravity base with a leg or legs projecting through the deck. At a preselected offshore station ballast is added to the gravity base and the platform descends slightly to a posture where the platform is buoyantly supported by the deck.

Abstract: An anchor apparatus to anchor houseboats or similar water craft comprising at least one retractable anchor element selectively movable between an upper or travel position and a lower or anchor position affixed to the houseboat having a swivel pad specifically configured to anchor the houseboat coupled to the lower portion thereof and a control device operatively coupled to the retractable anchoring element to control the vertical extension and retraction of the retractable anchor element to selectively extend the retractable anchor element downward relative to the houseboat to imbed the swivel pad in the bottom thereby anchoring the houseboat and to retract the retractable anchor element upward relative to the houseboat to permit normal travel of the houseboat.

Abstract: A diaphragm closure support system connectable to the inside of a pipe adjacent a diaphragm closure on the end of the pipe to prevent rupture of the diaphragm closure by hydrostatic pressure when the pipe is submerged in water. A diaphragm closure support ring having slots formed therein is welded to the inside of the lower end of the pipe. A diaphragm support plate, slightly smaller than the inside diameter of the support ring, is positioned to engage the resilient diaphragm closing the end of the pipe. A plurality of T-bolts are pivotally secured to the support plate and positioned to extend into the slots in a support ring. A T-bolt retraction ring is moveably secured to the support plate and positioned to urge the T-bolts into a locked position in the slots in the support ring.

Abstract: A method is disclosed for driving a pile into the ocean floor utilizing an underwater hammer. A leg of an offshore jacket structure is provided with several annular guide sleeves affixed to the leg at several spaced apart locations along the exterior of the leg. A pile is disposed underwater in the lower guide sleeves proximate the lower end of the structure leg. A housing assembly having a hammer mounted inside is lowered from the surface through the guide sleeves and into contact with the top of the pile, with the hammer being beneath the surface. The pile is driven by a succession of blows delivered by the hammer. The housing is then raised to the surface and moved to another driving location by an overhead sling.

Abstract: The disclosure relates to a compliant platform for use in deep water. The platform comprises a structure including a working deck positioned above the water by a plurality of leg members which are rigidly connected to the working deck and are pinned into the bottom of the body of water. Horizontal bracing members are rigidly connected between the leg members. Vibration-influencing means are located on the structure to provide the structure with a first mode of vibration with a frequency less than the frequency of the peak of spectral wave density profile expected in the body of water at the location of the structure and a second mode of vibration with a frequency greater than the peak frequency of the spectral wave density profile expected in the body of water at the location of the structure.