Abstract: A multi purpose hoisting device for use on a floating vessel having a deck, including: a load bearing structure to be mounted on the vessel; a main hoisting mechanism for raising/lowering an object above the deck and including: at least one main hoisting winch; an upper cable pulley block supported by the load bearing structure; a travelling cable pulley block; a main hoisting cable associated with the at least one main hoisting winch and passed over pulleys of the upper cable pulley block and of the travelling pulley block in a multiple fall configuration, such that the travelling cable pulley block is moveable relative to the load bearing structure by using the at least one main hoisting winch; a main hoist heave compensation mechanism associated with the main hoisting cable for damping the effect of sea-state induced motion of the vessel onto an object supported by the main hoisting cable.

Abstract: A method and device for establishing a borehole (26) in the seabed (4), comprising setting of a conductor (1), wherein the method is characterized in that it comprises:—providing the conductor (1) with a suction module (6);—then lowering the conductor (1) down to the seabed (4); and—displacing the conductor (1) down into the seabed (4).

Abstract: The invention relates to a device for manufacturing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a quantity of piles driven into an underwater bottom in a geometric pattern. The device comprises a positioning framework of a number of mutually connected guide tubes arranged in a geometric pattern and adapted to receive and guide a pile to be driven into the underwater bottom, wherein the guide tubes comprise a mechanism with which at least an internal wall part of the guide tubes is displaceable in the radial direction of the guide tubes from a radially inward support position for the pile to a radially more outward position in which the internal wall part substantially releases the pile. The invention also relates to a method and an assembly of a jack-up platform and the device.

Abstract: The invention relates to an underwater work assembly and to a method for anchoring the underwater work assembly in a bed of a lake, sea or river. The work assembly comprises a service platform which can be lowered and a plurality of supporting feet which are mounted so that they can be adjusted on the service platform for positioning on the lake, sea or river bed and can be moved in and out relative to the service platform by means of an actuating cylinder. In order to improve anchoring it is provided that at least one supporting foot is mounted rotationally relative to the service platform and that a rotary drive facing the supporting foot is provided, with which the supporting foot is driven in rotation for screwing into the lake, sea or river bed.

Abstract: A template for use in positioning subsea wellbores that has a drop away funnel that extends laterally from the template. The drop away funnel is used to locate a piling adjacent the wellbores and is selectively detached from the template after installing the piling. A tang and clevis type assembly mounts the drop away funnel to the template, where the tang and clevis are coupled together with a main stud. The main stud is oriented substantially parallel with an axis of the drop away funnel; so that when the stud is removed, the drop away funnel can decouple from the template and slide axially downward along the piling.

Abstract: A system configured to execute an underwater well drilling program in the bed of a body of water has a jack-up having a floating structure and a drilling installation supported on the floating structure; and an auxiliary floating unit connectable selectively to the jack-up to enable transfer of the jack-up over the body of water, even in very shallow water.

Abstract: A mobile drilling system comprising a top member with a drilling rig positioned thereon. The top member is removably engaged with a foundation member. The foundation member comprises a tower. The top member is moveable and adapted to be elevated out of the water for placement on top of the tower. The tower is preferably of concrete and extends out of the water and above any ice. A method is also described by which the top member is elevated out of the water either by jacking down legs or lifting by interaction with the tower.

Abstract: A floating offshore facility for offshore hydrocarbon production, comprising an upper deck, a lower deck, a well bay comprising a plurality of drilling slots and a plurality of production slots surrounding said drilling slots, a cart supporting a drilling riser and being movable together with said drilling riser inside the opening of the plurality of the drilling slots, and a drilling rig movable above the well bay to drill the well through the drilling riser.

Abstract: The offshore drilling system comprises a floating drilling vessel 1, a well drilled in the sea bottom 2, a tubular riser extending the well up to the floating vessel, well sealing elements fastened to the end of the riser at the level of floating vessel 1. The riser comprises tubular elements 12 connected to one another by connectors 13 designed to withstand the internal pressure of the well. Tubulars 12 comprise a metallic tubular body hooped by windings of fibers coated with a polymer matrix. The riser comprises several sections, each section consisting of tube elements whose hoop stress is determined as a function of the depth at which the section lies and of the mechanical strength of said metallic tubular body.

Abstract: The disclosure provides a method and system of installing subsea well trees, comprising: creating a glory hole having a depth below a seabed at a well location of a hydrocarbon reservoir; moving a floating offshore platform coupled with a foundation, the platform having a topsides and a caisson with downwardly extending walls defining an inner volume between the walls, the foundation coupled to the caisson walls, and the caisson walls having adjustable buoyancy; lowering the offshore platform with the foundation into the glory hole; drilling from the topsides into the hydrocarbon reservoir below the foundation to create a well; installing a well tree on the well, the well tree being disposed in the glory hole below the height of the seabed; coupling the well tree to a flow line; releasing the offshore platform from the foundation; and reusing the offshore platform to install other foundations at other predetermined well locations.

Abstract: A whipstock system for drilling a wellbore from a water bottom supported platform having wellbores with conductor pipes disposed through guide slots in a template on the bottom of a body of water includes a whipstock pipe extending from an equipment deck surface on the platform to a stab in sub. The whipstock pipe includes a window and j-slot mechanism for releasably engaging a scab liner. A stab in sub is configured to make mechanical connection between the whipstock pipe and a surface of a wellbore conductor pipe cut proximate the water bottom. The system includes a scab liner extending from the window to the water bottom when the stab in sub is engaged to the cut conductor pipe. The window is disposed above the water bottom. The scab liner configured to enable drilling a wellbore surface hole therethrough to a selected depth of a surface casing.

Abstract: A system including a setback and racking system and a set of wellbay accesses, at least a portion of the setback and racking system positioned at an elevation lower than the elevation of the wellbay accesses. A system including a centrally located setback and racking system, a set of wellbay accesses, and at least one peripheral skidding system, wherein the setback and racking system is positioned at least partially below the elevation of the peripheral skidding system. A system including at least one peripheral skidding system and a set of wellbay accesses positioned along a wellbay access perimeter surrounding a central focus that is not an integral part of the peripheral skidding system. A method of drilling by aligning each of at least two drilling modules with a respective wellbay access via a peripheral skidding system and operating at least two drilling modules at least partially simultaneously.

Abstract: A method for motion compensation includes obtaining measurements related to heave at a surface of a rig, transmitting the measurements to a processor, automatically transmitting a control signal from the processor to a motion compensation component in response to the measurements wherein the motion compensation component is a slip joint and is attached to a drill string located in the wellbore, activating the motion compensation component to compensate for motion in response to the signal, and preventing axial or rotational movement of a portion of the drill string below the motion compensation component.

Abstract: The invention relates to an underwater drilling arrangement for introducing a tubular foundation element into the bed of a body of water comprising at least one rotary drill drive, whereby a drill rod running inside the foundation element can be set into rotation by means of the rotary drill drive. The invention is characterized, among other things, in that a submersible working platform for placement onto the bed of a body of water is provided, whereby on the working platform at least one holding means for securing the foundation element in a rotationally fixed manner on the working platform is arranged and in that at least one mounting part for placement onto the foundation element is provided, whereby the mounting part has a clamping means for securing the mounting part on the foundation element, and the rotary drill drive is arranged on the mounting part.

Abstract: An apparatus, a system and a method for motion compensation use wired drill pipe to transmit downhole measurements from downhole tools to the surface. The wired drill pipe may transmit control signals from a terminal located at the surface to the downhole tools. In response to the control signals, a motion compensation component may enable the drill string to compensate for motion, such as, for example, heave. The motion compensation component may change a length of the drill string. A downhole tool having arms may be connected to the drill string and the wired drill pipe. The control signals may direct the downhole tool to move between an extended position and a retracted position.

Abstract: An apparatus for, and method of, lowering items from a drilling rig to a well located below it through the use of a landing string comprised of drill pipe having an enlarged diameter section with a shoulder, in combination with upper and lower holders having wedge members with shoulders that engage and support the drill pipe at the shoulder of the enlarged diameter section, the shoulder of the drill pipe and the shoulders of the wedge members being rotatable with respect to each other.

Abstract: A whipstock system for drilling a wellbore from a water bottom supported platform having wellbores with conductor pipes disposed through guide slots in a template on the bottom of a body of water includes a whipstock pipe extending from an equipment deck surface on the platform to a stab in sub. The whipstock pipe includes a window and j-slot mechanism for releasably engaging a scab liner. A stab in sub is configured to make mechanical connection between the whipstock pipe and a surface of a wellbore conductor pipe cut proximate the water bottom. The system includes a scab liner extending from the window to the water bottom when the stab in sub is engaged to the cut conductor pipe. The window is disposed above the water bottom. The scab liner configured to enable drilling a wellbore surface hole therethrough to a selected depth of a surface casing.

Abstract: A mobile drilling system comprising a top member with a drilling rig positioned thereon. The top member is removably engaged with a foundation member. The foundation member comprises a tower. The top member is moveable and adapted to be elevated out of the water for placement on top of the tower. The tower is preferably of concrete and extends out of the water and above any ice. A method is also described by which the top member is elevated out of the water either by jacking down legs or lifting by interaction with the tower.

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/gas interface level in a drilling riser up or down. The arrangement comprises a high pressure drilling riser and a surface BOP at the upper end of the drilling riser. The surface BOP has a gas bleeding outlet. The riser also comprises a BOP, with a by-pass line. The drilling riser has an outlet at a depth below the water surface, and the outlet is connected to a pumping system with a flow return conduit running back to a drilling vessel/platform.

Abstract: A system including a setback and racking system and a set of wellbay accesses, at least a portion of the setback and racking system positioned at an elevation lower than the elevation of the wellbay accesses. A system including a centrally located setback and racking system, a set of wellbay accesses, and at least one peripheral skidding system, wherein the setback and racking system is positioned at least partially below the elevation of the peripheral skidding system. A system including at least one peripheral skidding system and a set of wellbay accesses positioned along a wellbay access perimeter surrounding a central focus that is not an integral part of the peripheral skidding system. A method of drilling by aligning each of at least two drilling modules with a respective wellbay access via a peripheral skidding system and operating at least two drilling modules at least partially simultaneously.

Abstract: The invention relates to a centralization and running tool (CTR) in a subsea installation in connection with offshore related oil and gas exploration, where the subsea installation (SCM) is arranged to be placed on the ocean bottom or a drilling template and comprises a pipe-formed body (10), at least partially open at the top and extended, arranged to receive and carry through a drill stem (12) from a drilling rig or a drilling vessel. The centralization and running tool (20) is arranged to surround the drill stem (12) and to be placed in the pipe-formed body (10), and the centralization and running tool (20) comprises, together with the drill stem (12), a rotary packing housing (22) with a number of seals (24,26) that lie against the drill stem (12), and the packing housing (22), in accordance with the movements of the drill stem (12), is arranged for radial movement to take up angular deviations of the drill stem (12).

Abstract: The invention relates to an underwater drilling arrangement for introducing a tubular foundation element into the bed of a body of water comprising at least one rotary drill drive, whereby a drill rod running inside the foundation element can be set into rotation by means of the rotary drill drive. The invention is characterized, among other things, in that a submersible working platform for placement onto the bed of a body of water is provided, whereby on the working platform at least one holding means for securing the foundation element in a rotationally fixed manner on the working platform is arranged and in that at least one mounting part for placement onto the foundation element is provided, whereby the mounting part has a clamping means for securing the mounting part on the foundation element, and the rotary drill drive is arranged on the mounting part.

Abstract: An offshore universal riser system (OURS) and injection system (OURS-IS) inserted into a riser. The OURS/OUR-IS provides a means for pressurizing the marine riser to its maximum pressure capability and easily allows variation of the fluid density in the riser. The OURS-IS includes a riser pup joint with provision for injecting a fluid into the riser with isolation valves. The OURS includes a riser pup joint with an inner riser adapter, a pressure test nipple, a safety device, outlets with valves for diverting the mud flow, nipples with seal bores for accepting RCDs. The easy delivery of fluids to the OURS-IS is described. A method is detailed to manipulate the density in the riser to provide a wide range of operating pressures and densities enabling the concepts of Managed Pressure Drilling, Dual Density Drilling or Dual Gradient Drilling, and Underbalanced Drilling.

Abstract: An apparatus for, and method of, lowering items from a drilling rig to a well located below it through the use of a landing string comprised of drill pipe having an enlarged diameter section with a shoulder, in combination with upper and lower holders having wedge members with shoulders that engage and support the drill pipe at the shoulder of the enlarged diameter section, the shoulder of the drill pipe and the shoulders of the wedge members being rotatable with respect to each other.

Abstract: A system and method is described for well intervention in subsea installed oil and gas wells, comprising a surface vessel (10), or rig, with equipment (22) for handling and controlling a connection string (20) for downhole tools, and also a system (26) for the supply and return of drilling fluid, from where the connection string (20) for the downhole tool runs down in an actual drilling hole (36) of a well on the subsea, where a X-mas tree (12) with associated blowout preventer (16) is arranged on the well, and where a return line (24) for drilling fluid runs up to said system (26) on the surface vessel or the rig. The connecting string (20) for downhole tools runs into the well through open sea without a riser or landing string being fitted, and a removable intervention valve (14) is arranged in the drilling hole (36), where the intervention valve is arranged to function as a testable, temporary barrier.

Abstract: At least a portion of a subsea well is drilled casing-while-drilling techniques. A landing shoulder is formed within an outer string of a casing. The outer string of casing is secured to an outer wellhead housing above the landing shoulder and lowered into the wellbore. A casing hanger is attached to an inner string of casing and lowered through the outer string of casing into the wellbore. A drill bit at the at the lower end of the inner string of casing is rotated to deepen the well. The string of inner casing moves downward as the well is being deepened until landing the casing hanger on the load shoulder. A tieback member is attached to an inner wellhead housing and lowered into sealing engagement with the casing hanger. The inner wellhead housing lands in the outer wellhead housing.

Abstract: The disclosure is drawn to methods of drilling wells utilizing blow out prevention components of differing pressure ratings. In the initial drilling phase, a lower pressure rated blow out prevention component is used. In a subsequent drilling phase where a reservoir of a natural resource is penetrated, a higher pressure rated blow out prevention component is used.

Abstract: A system and method is described for use and return of drilling fluid/cuttings from a well, which is drilled on the ocean floor, in connection with offshore related oil production and gas production, where, from a drilling rig or drilling vessel (10), a drill stem (12) runs down into the bore hole and where a blowout preventer (BOP) is placed on said well, without mounting a riser between the rig or the vessel and said blowout preventer. A sealing and pressure-regulating device (16) is arranged on the blowout preventer (14) arranged to regulate the level of the drilling fluid, and thus the outlet pressure of the drilling fluid in said sealing and pressure-regulating device, and a pump module (18) is set up at a suitable distance adjacent said sealing and pressure-regulating device, where the pump module is arranged to pump said drilling fluid up to the ocean surface via an external return pipe.

Abstract: A riserless mud recovery system including a mud return line secured by an anchor is disclosed. Some system embodiments for drilling a well bore in an offshore location having a water surface and a subsea formation include an offshore structure positioned on a platform at a water surface, a drill string for forming the well bore suspended from the offshore structure, a drilling fluid source on the platform for supplying drilling fluid through the drill string, a suction module for collecting the drilling fluid emerging from the well bore, a return pipe coupled to the suction module, a pump for receiving the drilling fluid from the suction module and pumping the drilling fluid through the return pipe to a location at the water surface, and an anchor for securing the return pipe, where the anchor is coupled to the return pipe and the subsea formation.

Abstract: A subsea drilling method and system for controlling the drilling fluid pressure, where drilling fluid is pumped down into the borehole through a drill string and returned back through the annulus between the drill string and the well bore. The drilling fluid pressure is controlled by draining drilling fluid out of the drilling riser (8) or BOP (6) at a level between the seabed and the sea water in order to adjust the hydrostatic head of drilling fluid. The drained drilling fluid and gas is separated in a subsea separator (28) where the gas is vented to surface through a vent line (39), and the fluid is pumped to surface via pump (40).

Abstract: Methods and systems for drilling subsea wells bores with dual-gradient mud systems include drilling the subsea well bore while employing a subsea pumping system, a subsea choke manifold and one or more mud return risers to implement the dual gradient mud system. When a well bore influx is detected, the well bore is shut in, and components determine if pressure control may be used to circulate the influx out of the well bore, the size of the influx, and how much the mud system weight will need to be reduced to match the dual gradient hydrostatic head before the influx reaches the subsea pump take point. The subsea pumping system, subsea choke manifold, and mud risers are isolated while the influx is circulated up one or more fluid passages in the drilling riser package using the surface pump, through the wellhead, and out the surface choke manifold.

Abstract: According to one or more aspects of the invention, a method for drilling an offshore wellbore into a seabed from a platform positioned proximate to the water surface comprises making-up a first tubular string with a first conveyance assembly and running the first tubular string into the wellbore with the first conveyance assembly, wherein the first tubular string enters the wellbore from the water column at an entry position proximate to the seabed; performing a wellbore task with the first tubular string; while the wellbore task is being performed with the first tubular string, making-up a second tubular string in the water column from a second conveyance assembly; withdrawing the first tubular string from the wellbore with the first conveyance assembly once the wellbore task is completed; and running the second tubular string with the second conveyance assembly into the wellbore at the entry point from the water column.

Abstract: A drilling system comprising a pipe comprising a first end and a second end; a drill bit near a first end of the pipe, adapted to drill a hole in a formation; a pipe rotator near a second end of the pipe adapted to rotate the pipe; and a pump connected to the pipe between the first end and the second end, the pump adapted to transport a fluid from the first end of the pipe to the second end of the pipe, the pump comprising a first portion adapted to rotate with the pipe and a second portion adapted to remain stationary relative to the pipe.

Abstract: An aluminum riser assembly has a plurality of riser joints connectable together to form a riser string. When upper and lower joints are assembled, clamps support auxiliary pipes for carrying hydraulic lines. A drive rotates a sleeve rotatably supported on the upper joint, and the sleeve rotates a union nut rotatably disposed on the upper joint. As the union nut rotates, it moves axially along the riser joint and threads onto the lower joint. The union nut is tightened until it engages an external collar to complete the coupling between the upper and lower riser joints. The entire process can then be repeated for additional upper riser joints to make up a riser string.

Abstract: An underwater drilling rig (1) in modular form, which can be simply assembled underwater and in which standard tubulars and tubular assemblies are stored in a novel arrangement within containers (6) and can be added to, and removed from, the string in the well bore, whilst there is continuous circulation of drilling fluid and also continuous segregation of drilling fluid from the seawater.

Abstract: A subsea drilling system includes a drilling module having a tool carousel being removable and replaceable in or out of water, a skid module and an ROV to be connected to and disconnected from the skid module in or out of water, for operating the subsea drilling system with the ROV. A method for operating a subsea drilling system includes removing a tool carousel from a drilling module and replacing the tool carousel with another tool carousel, in or out of water. An ROV is connected to a skid module and disconnected from the skid module in or out of water. The subsea drilling system is operated with the ROV.

Abstract: A riserless mud recovery system including a mud return line secured by an anchor is disclosed. Some system embodiments for drilling a well bore in an offshore location having a water surface and a subsea formation include an offshore structure positioned on a platform at a water surface, a drill string for forming the well bore suspended from the offshore structure, a drilling fluid source on the platform for supplying drilling fluid through the drill string, a suction module for collecting the drilling fluid emerging from the well bore, a return pipe coupled to the suction module, a pump for receiving the drilling fluid from the suction module and pumping the drilling fluid through the return pipe to a location at the water surface, and an anchor for securing the return pipe, where the anchor is coupled to the return pipe and the subsea formation.

Abstract: A method for drilling a borehole in a producing subsea wellbore wherein a flexible conduit is connected at one end to a surface vessel and at the other end via a pressurized subsea wellhead to the producing wellbore such that a remotely operated electrical drilling device (RODD) can be deployed down the flexible conduit, the method comprising: directing a RODD to the location for drilling in the wellbore; and drilling a further wellbore section with the RODD; wherein the drilling comprises drilling in underbalanced conditions with respect to the formation; and using fluids produced from the formation to transport the drill cuttings away from the drilling device.

Abstract: Systems and methods for drilling a well bore in a subsea formation from an offshore structure positioned on a water surface with a drill string that is suspended from the structure and includes a bottom hole assembly adapted to form a top hole portion of the well bore. A drilling fluid source on the offshore structure supplies drilling fluid through the drill string to the bottom hole assembly where the drilling fluid exits from the bottom hole assembly during drilling and returns up the well bore. A suction module is disposed at the sea floor and collects the drilling fluid emerging from the well bore. A pump module is disposed on a return line, which is in fluid communication with the suction module, at a position below the water surface and above the sea floor.

Abstract: A floating rig or structure for drilling in the floor of an ocean using a rotatable tubular includes a seal housing having a rotatable seal connected above a portion of a marine riser fixed to the floor of the ocean. The seal rotating with the rotating tubular allows the riser and seal housing to maintain a predetermined pressure in the system that is desirable in underbalanced drilling, gas-liquid mud systems and pressurized mud handling systems. The seal is contemplated to be either an active seal or a passive seal. A flexible conduit or hose is used to compensate for relative movement of the seal housing and the floating structure because the floating structure moves independent of the seal housing. A method for use of the system is also disclosed.

Abstract: A system and method is described for use and return of drilling fluid/cuttings from a well, which is drilled on the ocean floor, in connection with offshore related oil production and gas production, where, from a drilling rig or drilling vessel (10), a drill stem (12) runs down into the bore hole and where a blowout preventer (BOP) is placed on said well, without mounting a riser between the rig or the vessel and said blowout preventer. A sealing and pressure-regulating device (16) is arranged on the blowout preventer (14) arranged to regulate the level of the drilling fluid, and thus the outlet pressure of the drilling fluid in said sealing and pressure-regulating device, and a pump module (18) is set up at a suitable distance adjacent said sealing and pressure-regulating device, where the pump module is arranged to pump said drilling fluid up to the ocean surface via an external return pipe.

Abstract: Devices and methods for obtaining cores from a sea bed. A corer device includes one or more core barrels for retaining a cores and one or more pressure barrels. Fluid pressure within the pressure barrels is selectively varied to cause the corer device to be drawn into and released from the sea bed. The core barrels are provided with core catchers for retaining a core within.

Abstract: An offshore riser system has riser joints, each having a pin and a box. The pin has an external grooved profile that is engaged by a locking element carried by the box of another riser joint. An actuating ring engages with the locking element to move it into the locked position. A retractable spider supports the string of riser while the new joint is being made up. A makeup tool on the riser deploying floor moves the ring relative to the locking element, causing the locking element to move to the locked position.

Abstract: A riser assembly includes a rotating control housing connected between an upper portion and a lower portion of a riser assembly, and a packing element rotatable with respect to the rotating control housing, wherein the packing element is configured to isolate an annulus of the lower portion from the upper portion when a drillstring is engaged through the packing element, and wherein the packing element is configured to be retrieved and replaced through the upper portion.

Abstract: Method for drilling and lining a well wherein at least one liner (1, 2, 32) with a larger external diameter than the substantial part of a drilling riser (10) is pre-installed at a point below the substantial part of the drilling riser (10). A bore hole section (21) is drilled after the drilling riser (10) has been installed, the bore hole section having a larger diameter than the at least one pre-installed liner (1, 2, 32). The at least one pre-installed liner (1, 2, 32) is subsequently lowered into the bore hole section (21, 22). A drilling and liner system for implementing the method is also described.

Abstract: A modular transfigurable drilling rig comprises one or more transfigurable containers with drilling equipment to form an operational drilling rig. The transfigurable containers include a first and second load bearing support and a load bearing bottom disposed between the first and second load bearing supports, thereby forming a space. The container includes drilling equipment rotatably attached to the load bearing supports or the load bearing bottom. The drilling equipment is disposed within the space. The drilling rig further includes one or more connectors adapted to engage at least two transfigurable containers together. The drilling rig further includes piping adapted to connect the drilling equipment together, cabling adapted to provide communication between the drilling equipment, and a power source connected to the drilling equipment, wherein the power source is adapted to provide power to the drilling equipment.

Abstract: The present invention relates to an underwater rock boring apparatus having differential global positioning system receiver and boring method thereof, new boring technology—a satellite navigation device orients the accurate position of a target—is brought to the underwater boring technology. A differential global positioning system (DGPS) receiver is provided at the body of a boring machine that is installed at the central opening of a self elevation platform (SEP) barge, the location of the boring machine is set to concentricity of the target boring position, and the position of the hull can be controlled without any movement of the boring machine. Then, the barge quickly moves to the next target boring location owing to the operation of a hull moving means so that the construction efficiency of the boring work can be enhanced.

Abstract: A method for drilling in the floor of an ocean from a floating structure using a rotatable tubular includes a seal housing having a rotatable seal connected above a portion of a marine riser fixed to the floor of the ocean. The seal rotating with the rotating tubular allows the riser and seal housing to maintain a predetermined pressure in the system that is desirable in pressurized mud cap and reverse circulation drilling. A flexible conduit or hose is used to compensate for relative movement of the seal housing and the floating structure because the floating structure moves independent of the seal housing. The drilling fluid is pumped from the floating structure into an annulus of the riser, allowing the formation of a mud cap downhole in the riser, or allowing reverse circulation of the drilling fluid down the riser, returning up the rotatable tubular to the floating structure.

Abstract: A method and associated equipment are disclosed which allow drilling at least a portion of a well and subsequently cementing casing in a single trip. The method is particularly suited for deep-water offshore operations where the drill string can be run through a section of casing leaving a bit and an under-reamer extending out below. The casing is equipped with ports through which cement can be pumped as well as an external casing packer to prevent the uncured cement in the annulus from U-tubing. Several casing sections can be run in during drilling and cemented succession using the one trip method.

Abstract: An apparatus and method for protecting against the problems associated with heave of a floating drilling rig are disclosed. The disclosed invention is a unique inline compensator in which a plurality of cylinders housed within a tubular housing and a plurality of low pressure and high pressure accumulators function together to provide a system for compensating for heave in the event a primary heave compensation system fails or becomes inoperative. The typical inline compensator of the present invention utilizes a plurality of hydraulic cylinders that act in opposite directions and that have different piston areas such that the piston rods of the cylinders are extended or retracted at different pressure levels to account for heave. The typical inline compensator of the present invention is self-contained and compact enough to fit in the limited space available on a floating drilling structure. Further, a pair of inline compensators of the present invention can be utilized with coiled tubing operations.