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: The present invention provides Ni (and/or Co) base precipitation hardened alloy compositions having improved resistance to stress corrosion cracking and being comprised of:12-25 wt. % Cr;0-10 wt. % Mo;0-12 wt. % W, with the proviso that Mo+0.5 W is .gtoreq.2 wt. % and .ltoreq.10 wt. % and with the proviso that Cr+Mo+0.5 W is .ltoreq.28 wt. %;2-6 wt. % of one or more of Al, Nb, and Ti;<0.05 wt. % C;<0.05 wt. % O;<0.05 wt. % N; and the balance being Ni (and/or Co) and any incidental impurities,wherein the concentrations of Ni (and/or Co), Cr and Mo (and/or W) are correlated so that their combination represents a point within the area ABCD of FIG. 1 hereof. Preferably, the ratio, expressed in atomic percent, of Al to Nb+Ti is between about 0 and 4.0, preferably between about 0.8 and 1.5, more preferably about 1. In addition, Hf is preferably included in a concentration, expressed in weight percent, of between about 10 (C+O+N) and 30 (C+O+N), more preferably between about 15 (C+O+N) and 20 (C+O+N).

Abstract: The present invention provides an approach for drilling offshore arctic wells in areas covered by floating ice. A grounded spray ice drilling structure having an inner drilling platform portion and an outer barrier portion which are contiguous is constructed by withdrawing water from beneath the ice sheet and spraying the water through the air when the air is below the freezing temperature of the water. This causes the water to freeze into spray ice as it passes through the air. The resulting spray ice is deposited on the ice sheet to build up the grounded spray ice drilling structure. The outer barrier portion is built up to a greater freeboard than the inner drilling platform portion, and is adapted to laterally confine the inner drilling platform portion and to protect the inner drilling platform portion from natural ice forces.

Abstract: The present invention provides an apparatus for aligning an integrated deck carried on a barge with a jacket secured to the seafloor. The apparatus comprises a plurality of cantilevered springs extending vertically downward from the deck and a plurality of sockets secured to the jacket, each socket being positioned to receive the lower end of one of the cantilevered springs. As the cantilevered springs are lowered into the sockets, wind or wave induced horizontal motion of the deck is accommodated by tilting of receiving members in the sockets. Once the cantilevered springs are fully engaged with the sockets, the receiving members no longer tilt and the great stiffness of the cantilevered springs permits only very slight horizontal motion of the deck so that the barge can be ballasted downward to transfer the deck load to the jacket without misalignment.

Abstract: A cable connector is provided which is particularly suitable for connecting tensioned armored cable sections used in wireline measurement while drilling operations or well logging operations. The cable connector comprises a pair of field latchable housings each attached to the braided outer covering of a cable, so that cable tension is transferred to the housings. The electrical connection between the inner flexible conductor wires of the armored cables is sealed from the environment within the housing by an elastomeric boot, with the boot being loosely positioned within the housing chamber by the flexible conductor wires. The housing need not isolate the electrical connection from the drilling fluids within the drill string, and the simplicity of the cable connector enhances both reliability and drill site assembly and repair.

Abstract: The present invention is a method for improving well cementing. A fluid such as drilling mud or preflush fluid is oscillated in the annulus prior to introduction of cement slurry into the annular interval to be cemented. The fluid is oscillated by changing its direction of flow at least twice. The oscillatory flow of the fluid flushes gelled drilling mud and filter cake from the annulus more effectively than conventional unidirectional flow. Following the oscillatory phase, cement slurry is pumped into the annular interval to be cemented, thus displacing the fluid, and is allowed to set. The fluid can be oscillated in the annulus either before or after the cement slurry is introduced into the casing. A selective check valve is also described which permits all fluids to flow in the forward direction out of the casing and into the annulus and which permits all fluids other than cement slurry to flow in the reverse direction out of the annulus and into the casing.

Abstract: The present invention is a process for the liquefaction of high pressure natural gas. The natural gas is expanded through a turboexpander to reduce its pressure and thereby cool it. The natural gas is then passed through a demethanizer to remove the heavier components therefrom. The natural gas is then precooled, before substantial warming occurs, by heat exchange with a C.sub.2 hydrocarbon refrigerant, either ethane or ethylene, contained in a single refrigerant system. The precooled natural gas is liquefied by heat exchange with a mixed refrigerant contained in a mixed refrigerant system. The mixed refrigerant consists essentially of nitrogen, methane and a C.sub.2 hydrocarbon, either ethane or ethylene. The mixed refrigerant contained in the mixed refrigerant system is cooled by heat exchange with the C.sub.2 hydrocarbon refrigerant contained in the single refrigerant system.

Abstract: A method and apparatus for installing a pipeline riser (90) through a J-tube (40) at a spud can-founded, compliant, offshore platform (20) are disclosed. The J-tube is mounted on the platform above the maximum expected mudline (28). An upper longitudinal section (44) of the J-tube passes through guide rings (46) on the platform while a lower longitudinal section (48) is maintained free of the platform. After platform settlement, the J-tube is lowered to an elevation near the actual mudline (30). During riser installation through the J-tube, a lower end (54) of the J-tube is restrained from lateral movement by a latch (70) attached to the platform. Before production operations, the lower end is released from the latch so that flexibility of the J-tube accommodates movement of the platform.

Abstract: A method is provided for constructing spray ice barriers to protect offshore structures in a frigid body of water from mobile ice, waves and currents. Water is withdrawn from the body of water and is sprayed through ambient air which is below the freezing temperature of the water so that a substantial amount of the water freezes as it passes through the air. The sprayed water is directed to build up a mass of ice having a size and shape adapted to protect the offshore structure. Spray ice barriers can also be constructed for the containment of pollutant spills.

Abstract: This invention relates to a composition of matter and to a method for producing a controllable, residue-free break of an emulsion or a dispersion of a water-in-oil emulsion. An emulsion breaker is incorporated into the emulsion. It is temporarily-protected (deactivated) so that breaking of the emulsion is initially avoided. By removing the protection, the breaker becomes active, and it acts to break the emulsion into its separate phases.

Abstract: The present invention is a torquemeter for measuring the torque applied during drilling operations. The torquemeter is of generally flat annular form and adapted to be positioned in the drive train around a Kelly and between the rotary table and the Kelly bushing and to rotate therewith. The torquemeter includes an annular torque link receiving forces from the rotary table whereby torque is transmitted from the rotary table to the torque link. The torque link has a set of bearing areas for receiving azimuthal forces from the Kelly bushing whereby torque is transmitted from the torque link to the Kelly bushing. Each of the bearing regions is mechanically isolated from the remainder of the torque link except for radially oriented bridging beams which support the isolated regions and serve as the sole conduits for transfer of mechanical forces from the isolated region to the remainder of the torque link.

Abstract: A method for controlling the flow of drilling fluid through a subaqueous wellbore is disclosed. The method comprises the steps of continuously measuring the output flow rate (A) of the drilling fluid from the wellbore, the input flow rate (B) of the drilling fluid to the wellbore, and at least a component of the pitch and roll (P/R) of the vessel, computating a floating alarm limit (C) dependent upon the pitch and roll (P/R) signal and the roughness of the sea, filtering the periodic fluctuation of the output flow rate (A) due to the motion of the vessel, and computating the delta flow signal (D) by subtracting the input flow rate (B) from the filtered output flow rate (A).