Abstract: A mat jack-up drilling platform converted to a floating drilling platform. The mat jack-up platform, which normally contains a platform, a mat for resting on the seafloor, and legs attached at one end to the mat and on which the platform can be raised and lowered, is converted to a floating rig by jacking the mat to the platform, permanently joining the mat to the platform, and removing the legs.

Abstract: A structure that is floatable on a ocean surface and that is fixable relative to an ocean bottom. The structure includes an array of floatable, submersible caissons and a floatable box girder capable of supporting a modular superstructure. The box girder is floated to a position on the ocean surface above the submerged array of caissons. The array of caissons is then raised to engage and connect with the box girder. The caissons may also be secured to the ocean bottom.

Abstract: A relatively light-weight offshore structure with design characteristics that allow it to be installed in a water depth up to two hundred fifty (250') feet with a conventional jack-up drilling rig or a small derrick barge. The structure consists of one (1) vertical pipe column that is driven into the sea floor, which can be used as a conductor for a well and may also support a platform with wellhead deck, production equipment deck, heliport, etc. The vertical column is collar clamped and welded to a submerged support brace assembly. The brace assembly is rigid, light, floats during installation, and is self-uprighting. It consists of two (2) main diagonal support legs that are connected to the vertical column near the water-line, and has two (2) pile connection sleeves at its base for piles to be driven into the sea floor. The support piling may be pre-loaded into the support brace assembly for ease of offshore installation.

Abstract: Method and apparatus for making a dock or seawall. A forming float device, comprising a forming deck and ballasting means therebelow, floats in a body of water a selected distance from the shoreline. A first wall section is formed on the top surface of the forming deck, such that the first wall section rests horizontally on the surface of the deck, and comprises a plurality of wall pieces whereby the wall pieces are aligned and shaped appropriately to together provide a uniform wall. Each wall piece is fastened by fastening means to the top surface of the forming deck. Earth reinforcing strips are installed in each wall piece such that the earth reinforcing strips extend upwardly from the wall pieces generally perpendicular to the planes defined by the wall section and forming deck and the earth reinforcing strips are secured in that upward position. Alternatively, a bundle of cylindrical containers may be attached together and to the wall section. The forming float device is rotated 90.degree.

Abstract: Flexible column for offshore applications made from a composite material consisting or consisting essentially of a thermosetting resin reinforced with natural, artificial or synthetic fibers.

Abstract: A method and apparatus for offshore support structures utilizes a hollow pile disposed within one leg of a three-legged structure to support an offshore platform, wherein the hollow pile is fixedly secured to the tubular leg within which it is disposed.

Abstract: A method of constructing a column-like marine structure including the steps of constructing and placing an assembly of floats in a dry area, placing on the float assembly a column base having its own buoyancy, flooding the area to float the assembly of floats and column and moving them to deeper water, ballasting the floats to sink them and while maintaining buoyancy of the column removing the floats, completely ballasting the column to sink it, reconnecting the floats around the top of the column, constructing a further column part on top of the column, lifting the assembly by the buoyancy of the floats and/or the buoyancy of the column and floating it to a desired location in deeper water.

Abstract: Procedure for the construction of a concrete shaft for a platform or similar structure, where one of several of the shafts will be outfitted with relatively much equipment. The shafts are constructed of prefabricated sections which are consecutively installed butt-in-butt on top of each other and which are left in the shaft as an internal fully shaped shaft component, as the sections internally contain associated equipment and externally feature bodies for the installation of easily removable formwork elements, preferably easily mountable slipforms, while the space between the formwork elements and a prefabricated section is filled with reinforcement and concrete. The formwork elements, after the hardening of poured concrete, by a per se known procedure, are moved to a higher level.

Abstract: An underwater building comprises a floating base that is to be fixed to a bottom under water or the sea and a building body is constructed on the base. The base floats on the water surface before construction of the body of the building, and the building body formed thereon has a double-walled construction having an opening between an outside wall and an inside wall. Water is selectively poured into and drained from the opening, and by its weight the building body is controllably sunk into the water. Only a gateway tower portion made in the upper portion of the building body is eventually left projecting out of the water.

Abstract: Offshore well drivepipe or caisson may be supported by a skeletal frame type supported having spaced apart caisson receiving guide sleeves and spaced apart sets of pile guide sleeves interconnected by lateral and diagonal brace members. The support may be totally submerged and sleeved over the caisson while resting on the seabed and secured thereto by conventional piles which are installed through the pile guide sleeves and driven to temporary or permanent depth. The support structure provides a low-cost, reusable, temporary or permanent support for well caissons or drivepipes.

Abstract: A system for positioning and mounting a large structure over a template lying on the ground or on the seafloor, uses a guide ring and a guide slot, both fixed to the structure, for guiding and holding onto two docking piles during a mating operation. These piles have been driven or drilled down into the seafloor/ground in advance through guide members fixed to the template.

Abstract: The present invention is directed to a water-based correctional facility, a water-based correctional system including a ship or ship hull converted into a water-based correctional facility and a method of converting a ship or ship hull into the correctional facility or system. Preferably, the correctional system includes a water-based pier and vehicular bridge. The correctional facility includes all the features and capabilities of a typical land-based correctional facility.

Abstract: A motion absorbing docking assembly for use in subsea docking operations. A tubular docking pile receives a pile head assembly in which a retractable pile head is positioned. When the pile head is impacted by a docking guide on a jacket being lowered into place, axially spaced shock cells having a common central support member absorb the relative motion between the pile head and the docking pile. This arrangement provides for absorption of twice the distance that each individual shock cell is capable of absorbing by itself.

Abstract: A support device on the sea-bed for legs of a self-elevating oil-rig platform are characterized in that it comprises an individual and independent shoe (3) intended to be fixed on the lower end of the leg (2) and fitted with a detachable and adjustable locking means (20), for fitting rigidly on the said lower end of the leg (2) .

Abstract: A method and apparatus for positioning in the sea a buoyant platform having a plurality of legs which are movable relative to the platform. One or more tubular elements are detachably suspended from one or more of the legs, such that upon lowering of the legs relative to the buoyant platform, the tubular elements come into contact and rest on the sea bottom. The tubular elements are preferably detached from the legs and a filler material such as gravel is filled into the open ended tubular elements, thereby forming one or more foundations upon which the legs can rest so that the platform can be jacked upwardly relative to the legs and extend above the sea level.

Abstract: Method and apparatus for lowering a heavy hollow column into hard soil and rock at the bottom of a body of water which column has a downwardly widening outer surface and a sharp lower edge. By means of plurality of suction nozzles erosive water flows are generated alongside and below the lower edge which sharp lower edge due to the erosive effect of the water flows and the local tensions generated in the soil by the weight of the column disintegrates the soil.

Abstract: A method and apparatus for offshore support structures utilizes a hollow pile disposed within one leg of a three-legged structure to support an offshore platform, wherein the hollow pile is fixedly secured to the tubular leg within which it is disposed.

Abstract: The present invention is of a deepwater platform which incorporates a central two-piece tower extending from the ocean floor to at least a few feet above the ocean surface. The central tower is divided into an upper tower section and a lower tower section, with the lower tower section being substantially higher than the upper tower section. The tops of outwardly and downwardly positioned struts are connected to the tower at the dividing point between the upper and lower tower sections. Both the lower end of the central tower and the lower ends of the struts are anchored to the ocean floor by driving piles through pile sleeves secured thereto. The dividing line between the upper tower section and the lower tower section depends upon the angle at which the struts are positioned against the tower.

Abstract: Method of erecting a minimal structure offshore platform around an existing caisson or drive pipe without any bolted, grouted, or underwater welded connections. This method involves the welding of a stop ring onto the caisson at a point just above the water line. A template having two sleeves for receiving piles and a sleeve for receiving a caisson is lowered over the caisson until the template rests on the stop ring. The template is concentrically aligned by a shim mounted to the top of the caisson sleeve. The caisson sleeve is centered around the caisson by inserting shims between the caisson and the caisson sleeve, and then the caisson sleeve is welded to the caisson and the stop ring. Piles are driven through the pile sleeves to grade using shims on the high point of the pile sleeve to align the pile with the axis of the sleeve as the pile sections are welded together. Once the piles are driven, the pile sleeves are centered around the piles by inserting shims between the piles and the piles sleeves.

Abstract: Method and apparatus to stabilize a columnar platform for deepwater offshore applications. An added mass stabilizer system is utilized to control first order heave, pitch, roll, surge and sway motions of the floating platform. The stabilizer is suspended beneath the platform by a set of tendons a sufficient distance to (1) enter a quiescent zone beneath the action of waves and currents, (2) provide a sufficiently long movement arm to resist pitch and roll torquing, and (3) incorporate sufficient flexibility into the suspension system to avoid shock loads. The stabilizer is sized to (a) provide sufficient submerged weight to maintain the tendons in constant tension and, (b) create adequate added mass (actual stabilizer weight plus mass of water moved by the stabilizer) to provide the desired control of first order motions. A secondary mooring system such as a spring-buoy mooring or dynamic positioning system can be provided to control drift produced by higher order motions and first order yaw.

Abstract: A tension leg platform for drilling and/or production, processing and transporting hydrycarbons from sub sea wells or installations, and methods for installation of such platform. The platform comprises in operational position the following: a working platform which has position above the sea level, a buoyant body (1) which is connected with the underside of the platform and has substantially position below the surface, and a number of tension legs (13) which connect the buoyant body (1) with a fundament anchored to the sea bed. The invention is characterized in that the lower parts of the tension legs (13) in per se known fashion are anchored to the fundament (14) and at their upper ends are controlled in guides (20, 21) on the outside of the buoyant body and are attached to the buoyant body (1) above or just below the water line.

Abstract: The floating structure comprises one or more catenary mooring cables for anchoring the structure to the seabed. An extensible dynamic tensioner system is provided for maintaining a predetermined dynamic tension in each mooring cable, as the structure responds to cyclic wave forces, and for increasing the natural periods of oscillation of the pitch, roll, heave, surge, sway, and yaw motions of the moored floating structure by reducing the spring stiffness of the mooring system. A motion damping system is coupled between the dynamic tensioner system and the structure for damping the linear and angular displacements of the structure relative to the tensioned cables. The damping system selectively applies frictional forces against a movable member in the tensioner system. The movable member does not move relative to the cables.

Abstract: A system and method for mating a preconstructed integrated deck mounted on a barge with a previously installed offshore jacket is provided. The system comprises at least two primary load transfer units, at least one secondary load transfer unit, and a plurality of drop block assemblies. The primary load transfer units are designed to absorb a portion of the weight of the integrated deck as the integrated deck is lowered onto the jacket. The secondary load transfer units are designed to engage after a portion of the weight of the integrated deck has been absorbed by the primary load transfer units and to assist the primary load transfer units in absorbing an additional portion of the weight of the integrated deck as it continues to be lowered onto the jacket. The drop block assemblies are designed to disengage the integrated deck from the barge and thereby transfer the remaining weight of the integrated deck to the jacket.

Abstract: The invention relates to a process and a floating apparatus (1, 2, 18) for the construction of columnlike elements (16, 17), forming part of a pier, a jetty or the like marine structure, in which a first part (16) is manufactured on a support (5) attached to the floating apparatus. Whilst said apparatus rests on the waterbottom (15), which first part (16) is lowered on the waterbotton (15) after lifting the floating apparatus to free it from the waterbottom and after displacement to a place with deeper water. There the next part (17) is made upon the still deeper water, lowered again until they rest on the bottom, after which the next part is made and so on until the final height and destination are reached. The floating apparatus is completely equiped (10, 11, 14) for performing the work and has a construction such, that it can be disengaged from the finished structure.

Abstract: A method and apparatus for offshore support structures utilize a central support having three legs interconnected with an outrigger support structure comprised of at least two legs and at least one hollow pile is disposed within at least one leg of the central support, the hollow pile being fixedly secured to the tubular leg within which it is disposed.

Abstract: A method of installing a floatable or buoyant body on the sea floor includes towing the body to an installation site at the sea surface and subsequently submerging the body towards the sea floor by supplying ballast to the buoyant body. The supply of ballast is discontinued when the buoyant body reaches a preselected sinking velocity and the vertical movement of the buoyant body is discontinued at a predetermined level above the sea floor by a floating vessel or the like which is floating at the sea surface. One end of the vessel is connected to the buoyant body by a connector system, the length of which is smaller than the sea depth at the installation site. The buoyant body is displaced laterally to a preselected final location, whereafter the buoyant body is further submerged towards the sea floor until the same is positioned on the sea floor at a preselected installation site.

Abstract: A marine structure which includes a jack-up platform assembly having a platform and at least three support legs, each leg having a generally cylindrical adapter at a lower end thereof. A support assembly includes a receptacle for each of the support legs, the receptacle mating with the support leg adapter and supporting the platform assembly, enabling the platform to be jacked up above an ocean surface. A stop assembly is removably attached to each of the support legs, the stop assembly being spaced from the support leg adapter and including a stationary part which mechanically engages a portion of the receptacle when the support leg adapter penetrates a predetermined distance into the receptacle. The stop assembly is secured to the receptacle by pins extending through a part of the stop assembly and a part of the receptacle.

Abstract: A platform consisting of a rigid structure supporting the deck, floats fixed to the lower part of the rigid structure, and flexible structure formed of piles fixed by their upper ends to the rigid structure and to the floats and by their lower ends to a base provided on the seabed, the piles being held under tension.

Abstract: A transportation and construction method utilizing construction components of the type comprising vertically spaced pairs of male and female lock assemblies, with vertically reciprocating female locks for locking horizontally extending pin members of the male lock assemblies into receiving sockets of the female assemblies, comprising the steps of transporting a plurality of construction components having such lock assemblies to a construction site in the manner of standard freight containers, emplacing a first such component at the site supported by an underlying earth formation, positioning a second such component adjacent the first component, placing at least some of the female locks in raised or release positions, mating pin members with the respective sockets of the raised female locks, and then lowering the female locks to lock the second component to the first component and support it thereon in cantilever fashion, then extending supports downwardly adjacent the second component into load bearing engage

Abstract: A method of constructing and assembling huge modules whose module frame includes sidewalls, a roof, trusswork frames and at least one deck structure secured within and to the module frame involves introducing a separately built deck structure into the module frame at floor level. The introduction is either through a temporary lower opening in a side wall frame, or from beneath the module frame. The deck structure is then positioned within the module frame, controllably elevated therein to a desired level and then secured to the module frame. This sequence is repeated as required such that additional separately built deck structures are similarly introduced into the module frame, positioned, elevated therein and secured thereto. After the desired number of deck structures has been installed, any lower opening in the sidewall frames is closed with trusswork braces.

Abstract: For rapid assembly of the deck of a drilling platform on a pipe scaffold, a connecting element made of two interlocking parts is described. The first part is in the form of a closing head integrated by casting into the end of a vertically standing pipe of the pipe scaffold, a ring-shaped horizontal support surface and a lifting bitt extending upward. The second part is in the form of a bell-shaped cover which envelops the lifting bitt. The cover on its upper surface is welded to the drilling platform, and at its underside includes a supporting surface which bears upon the supporting surface of the first part.

Abstract: A method and apparatus for transporting a marine superstructure on a vessel floating in a body of water to a working site, placing the semi submersible part of the apparatus into a body of water, lowering the semi submersible into a stable position, moving the marine superstructure from the vessel and onto the semi submersible, elevating the semi submersible with the marine superstructure over the marine structure, lowering the semi submersible vessel and the marine superstructure, causing the marine superstructure to rest on the marine structure, pulling the semi submersible away from the marine structure and marine superstructure and placing the semi submersible back onto the vessel. To remove the marine superstructure from the marine structure and place the marine superstructure onto the vessel the same method is used in reverse.

Abstract: A method and apparatus for making a dock or sea wall whereby the wall comprises at least one sectional dock member, the dock member comprising a concrete base section and a concrete wall section perpendicular to and attached thereto. A forming float device is used to make each sectional dock member while the forming float device floats in a body of water (e.g. sea). Both the base and wall sections of the dock member are formed horizontally on the water, thereby simplifying the means of constructing and positioning the dock members. The forming float device provides a base section forming surface and a wall section forming surface perpendicular thereto. Rotation means are used to rotate the forming float device from a first position in which the base section is horizontally formed to a second position in which the wall section is also horizontally formed. Then the forming float device is rotated a third time to properly orient the dock member prior to positioning the dock member on the sea floor.

Abstract: Both an offshore platform mating system and method are disclosed in which adjacent first and second jacket sections are provided with a plurality of corresponding docking poles and receptacles, respectively. Alignment of the adjacent jacket sections is facilitated by using at least one extended or lead docking pole on the first jacket section which projects further toward the second jacket section than do the other docking poles and is thus the first to engage one of the horizontally aligned receptacles when the first and second jacket sections vertically approach. Mating procedures for the first and second jacket sections continue with rotational alignment of the first and second jacket sections about the lead docking pole which acts as a pivot while alignment of the other receptacles is adjusted with respect to the other docking poles.

Abstract: Structures with inter-connecting members such as shores, struts, braces and the like which are subject to compression and/or tension stresses can be erected even when the foundation strata do not exactly meet anticipated levels, or when differential settlements occur at base points after loads are applied. At least one of the structural members is in the form of a first elongate section having a hollow mating end, and a second elongate section including a hollow bell-shaped end. The mating end of the first section is slidably received in the bell-shaped end of the second section, and the first and second sections are allowed to slide axially of one another at least during erection of the structure. At a desired time after erection, relative sliding movement between the first and second sections is prevented, thus fixing the length of the structural member.

Abstract: The present invention relates to an improved caisson structure which is adapted to support a production platform above the water and has its base on bottom and has a foot print or base which will pass through the drilling slot of a jackup rig. The caisson structure includes a large diameter caisson supported in a base structure including at least three base columns through which piling is placed and bracing extending between the columns and the caisson, a platform supported at the upper end of the caisson with production tubing and its casing extending upward through the caisson, and where desired, filled with concrete surrounding the casing within the caisson. The improved caisson structure can be used to surround and support an existing conductor pipe extending from a subsea wellhead to the surface or to surround a wellhead at the surface and the conductor which extends to such wellhead from a subsea well bore.

Abstract: An offshore platform mating system of the present invention is disclosed in which an upwardly open lower receptacle is provided on upper extensions of leg portions of a jacket bottom section of the offshore platform for receiving a mating pin so as to project a docking pole upwardly. Downwardly open upper receptacles are provided on the lower extensions of each leg portion of the corresponding jacket top section and are disposed to receive the upwardly projecting docking pole of the mating pin. A connection is provided for securing the jacket top section to the jacket bottom section. A method is also disclosed for installing the offshore platform utilizing the mating pins.

Abstract: A method of stabilizing a floating body comprises applying to the body a vertical force so as to maintain the body in an equilibrium position which is spaced vertically from the normal floating position of the body, in which the vertical force comprises a limited vertical force applying means acting on the body in one vertical direction and a flexible tension member applying tension to the body or the force applying means in the opposite vertical direction, the tension member having a tension less than the said limited vertical force.

Abstract: A load transfer system and method for its use for mating an integrated deck structure onto an offshore platform substructure at an offshore location is disclosed. The load transfer system utilizes a probe extending downwardly from the integrated deck and adapted to mate with the substructure, and a shock-load absorbing system having a first spring with a linear compressive response and a second spring with a variable compressive response mounted in series between the integrated deck and the probe.

Abstract: The equipped deck (1) is charged onto a self-elevating platform (2). The platform is positioned close to the fixed platform (11) and the deck is lifted from the self-elevating platform (2) to the level of the fixed platform (11). The deck is slid on the fixed platform (11) by means of a cradle (6) mounted on blocks provided with regulating jacks. The blocks co-operate with sliding ways provided on each of the platforms. The two platforms are coupled by means of a guiding frome (12).

Abstract: A method of assembly of an offshore tower comprises engaging a column with a sleeve of a support structure by positioning the column so that its longitudinal axis is vertical or nearly vertical, positioning the support structure so that the column-receiving sleeve is uppermost and the axis of the sleeve is vertical or nearly vertical, with the sleeve above the top of the column, and positioning the column in the sleeve by relative longitudinal movement between the column and support structure.

Abstract: A modular spaced framed structure is constructed using uniform components to provide the desired geometry of the modular structure. The structure is comprised of a plurality of rigid Y-shaped devices, each of which has three tubular branches which are disposed at respective predetermined space angles with respect to one another, and a plurality of panels spanning the spaces between the devices. Linear coupling members are also provided for interconnecting abutting branches of adjacent devices. In the preferred embodiment the three branches of each device are oriented at respective space angles of 108.degree., 108.degree. and 108.degree. so that a tower structure having a pentagonal horizontal cross-section is formed. Each successive level of the tower below the apex has a substantially greater area than the level above it so that the legs of the tower are inclined to provide greater resistance to earthquake forces.

Abstract: A jacket for supporting an offshore platform or the like comprises at least one vertical column member, laterally and vertically spaced guide sleeves for piles to be driven into the sea floor and lateral bracing connecting the guide sleeves to the column member. The jacket may be installed with the piles prepositioned extending through the guide sleeves and temporarily secured thereto until the jacket and pile assembly is in position on the sea floor and ready for pile driving. The vertical column member may receive a pile which may include a well casing. A method of installation for the jacket may include drilling a well through the column member after installation of the jacket and securement to the sea floor by the piles which extend through the guide sleeves.

Abstract: A compliant offshore structure in which the primary restoring force to lateral displacement is provided by elongate flex elements. A gravity base is rigidly secured to the ocean bottom. A tower extends vertically upward from the base to a position above the ocean surface. A work deck is supported atop the tower. The tower is secured to the base by elongate flex elements which are arranged in an array surrounding the central axis of the structure. Each flex element has one end secured to the base and a second end secured to the tower. The flex elements permit the tower to pivot about its lower end, thus providing the tower and deck with a compliant response to environmental forces. The flex elements also support the tower above and free from contact with the base. This eliminates the need for a vertical load bearing joint between the tower and base.

Abstract: An arctic offshore platform adapted for use in hydrocarbon exploration and production operations conducted in relatively shallow waters with low to moderate ice environments. The arctic offshore platform of the present invention includes one or more support legs. Each support leg includes a base resting on the ocean floor, a central support column extending upward through the base to a position above the ocean surface and a sloped-sided member seated atop the base and extending upward around the central support column to a position above the ocean surface. In installation, the base and central support column are installed and secured to the ocean floor as a unit. Following this, the sloped-sided member is secured atop the base. The sloped-sided member causes ice sheets which may impact the support leg to fail in flexure, thus reducing the overall ice loadings on the support leg relative to the loading which would exist were the sloped-sided member absent.

Abstract: A tension-restricted articulated platform tower for offshore oil and gas production. Two or more tower segments of increasing lateral dimension (proceeding toward the ocean floor) are stacked and articulated by means of a resilient joint. The platform tower behaves as a fixed tower under normal quiescent conditions with each of the segments above the base segment sitting thereabove in an at rest position. When forces sufficient to unseat the compressed resilient joint element are directed against the platform tower (e.g., from wind, waves, or water current), the tower behaves complaintly with tension elements secured to each corner post providing a restorative force proportional to the amount of tower movement.

Abstract: Arrangement in an offshore concrete platform comprising a base structure (1) and at least one tower structure (3) having a tower foot (5). The tower foot (5) is supported by a pair of annular, downwardly diverging, conical shell structures (6,7) forming a transition to the base structure (1). The shell structure (6,7), having angles of inclination which can be varied independently of each other, advantageously may be supported directly by the walls of respective cylinders (11,12) being an integral part of the walls of the base structure (1). The structural shape and geometry of the arrangement implies that the size of the diameter of the tower foot (5) can be chosen independently of the size of the base.

Abstract: A support device for a leg (2) of an off-shore drilling jack-up platform including a separate heightener (3) adapted to be interposed between each leg of the platform and the sea bed so as to increase the depth of installation of the platform. Each heightener is provided with detachable means (4, 7, 11, 12) for connecting the heightener to the lower end (4) of a respective leg (2) which improves the strength thereof.

Abstract: A system for mating an integrated deck structure with an offshore substructure is provided. The system comprises a spud can attached to a leg of the integrated deck structure and a bin attached to a leg of the substructure for receiving the spud can. The bin contains a bed comprising a medium having variable stiffness and damping characteristics which is utilized to minimize the dynamic forces that occur between the integrated deck structure and the substructure during the mating procedure.

Abstract: A load transfer device and method is disclosed for rapid, controlled transfer of a load between two support surfaces such as transfer of a prefabricated deck from a barge to an offshore deck support structure. The load transfer device connects a piston chamber to a support base on the barge and receives the prefabricated deck on one end of the piston rod, the other end of which is received within the piston chamber and is supported upon an enclosing membrane of a bladder assembly which distends and contracts as hydraulic fluid enters and is dispelled therefrom to raise, support or lower the piston rod.