Abstract: A system for running riser pipes from a floating vessel to each of a plurality of conductors set in the sea floor in a circular pattern. A vertically mooring guidance riser is first connected between the center of the pattern and the floating vessel. A permanent riser pipe is guided down to one of the conductors by use of a guide frame positioned on the guidance riser. When all of the permanent riser pipes are run, the guidance riser may be removed. Special running tools and guide frames are described.

Abstract: An inspection tool for detecting any flaws or defects in the upper end of a string of casing set in the bottom of a body of water. The tool has a cylindrical housing carrying a radiographic-sensitive film which fits over the open end of the string of casing and a radiographic source supported in the axis of the cylindrical housing. Means are provided for raising and lowering the tool.

Abstract: This invention relates to a floating production system for offshore development of oil and gas wells which employs an underwater buoy to decrease tension on flexible riser pipes used to connect a subsea pipeline to the floating vessel. The underwater buoy utilizes a cradle assembly having a drag balancing tail assembly to counteract the twisting moment applied to the cradle by current drag forces.

Abstract: This invention relates to an apparatus for cutting cores from the sidewall of a borehole after the borehole has been drilled. The apparatus includes an elongated housing which supports guide means which provides a path along which a core bit and motor can be moved to extend and retract the core bit. The guide means has a rotational control section and a transverse control section. The rotation control section guides the motor and its core bit from an upright position in the housing to a selected angle and the vertical transverse control section guides the coring bit means in the direction of the formation.

Abstract: This relates to drilling in water from a platform or vessel using a riser pipe. An inverted funnel skirt or cone is placed over slots cut in the wall of a riser pipe a short distance above its lower end. The apex end of the cone is welded to the riser pipe above the slots and drill cuttings pass through the slots and fall to the seafloor. Another embodiment includes an "L" shaped diverter flowline welded to the periphery of each hole in the riser pipe with one leg of the "L" extending a short distance below the hole.

Abstract: An injection well control method and apparatus controls fluid injection rates during secondary or tertiary petroleum recovery operations by monitoring bottomhole pressure adjacent an underground formation receiving the injected fluids while simultaneously adjusting the fluid injection rate to substantially reduce unwanted variations in said bottomhole pressure. The injection controller is further adapted for operation on a solar-powered circuit to eliminate the need for electrical power lines in remote geographical locations.

Abstract: An ice island is constructed in a marine area having a sheet of natural ice by mining ice blocks from the ice sheet, curing the blocks and placing the cured blocks directly on the ice sheet until the natural sheet touches bottom and the desired weight of the ice island is obtained. Methods are disclosed for special placement of the blocks to prevent overstressing the natural ice sheet.

Abstract: A method of core cutting and apparatus operable on a seven conductor wireline logging cable for drilling a hole in the sidewall of a drill hole which comprises an elongted housing with a hydraulically operated backup shoe mounted within the housing for wedging the housing at a selected location in the drill hole and a hydraulic motor with a drilling bit connected thereto for rotation by the hydraulic motor. Hydraulic means are mounted within the housing and are connected to the hydraulic motor for moving the bit into drilling engagement with the sidewall of the drill hole. In one embodiment, a core cutting bit is connected to the motor for obtaining a sample of a subterranean formation at the selected location.

Abstract: Means are provided for latching a Vertically Moored Platform riser spacer to the riser pipes which connect a floating platform to a subsea anchor. This includes a spring loaded latch pin recessed in a hole in the riser donut housing which surrounds the riser and which is released by pulling a spring loaded latch release pin to let the latch pin move outwardly to a latched position where it is held in this position by a spring loaded shear pin. To disengage the latch pin, a hydraulic ram or other means can be used to shear the retaining pins and remove the latch pin.

Abstract: Special J-slot connectors have been devised for connecting concentric riser pipes and casing from a structure at the surface of a body of water to corresponding concentric casings set in the sea floor. This can be called a "tieback tool" for sealingly securing a first tubular member suspended from a vessel floating on a body of water to a casing hung in the wellbore in the bottom of the body of water. Special multiple axially aligned J-slot means are also provided together with means to assure proper "makeup" of the J-slots. Means are also provided for proper alignment of circumferentially spaced J-slot connectors. Special self-emergizing seals are also disclosed.

Abstract: Method and apparatus are described to reduce the tension required on a riser pipe used in offshore drilling between a floating vessel and a subsea wellhead. Heavy drilling fluid is circulated down a drill pipe and up the annulus between the drill pipe and the borehole wall to a point just above a subsea wellhead. From this point, a separate drilling fluid return conduit extends to the floating vessel. Means are provided to maintain a constant level of an interface between the heavy returning drilling fluid and the lightweight fluid which can be confined within the riser pipe.

Abstract: An unarticulated riser pipe for connecting a subsea pipeline to facilities on a floating platform. The riser pipe has a vertical section which is rigidly attached to a horizontal section which provides flexibility. Means are provided to maintain the tension on the vertical section. In one embodiment, a subsea frame aids in connecting the horizontal and vertical sections and then to set a limit on permitted motion of the riser pipe.

Abstract: This describes a method of performing operations in a well selected from a group or cluster of subsea wells which are produced through a production riser means to production facilities on a floating platform. There is provided a flexible workover riser on the platform which extends through a passage on the platform at a location remote from the moon pool for the production riser means. The flexible workover riser is run through said passage and guided into connection with the production tubing in the subsea well. Wireline or other well operations are then conducted through the connected flexible workover riser from the floating platform.

Abstract: An apparatus operable on a wireline logging cable for drilling a hole in the sidewall of a drill hole which comprises a hydraulically operated backup shoe for wedging the apparatus at a selected location in the drill hole, a hydraulic motor with a drilling bit connected thereto for rotation by the hydraulic motor and hydraulic means connected to the hydraulic motor for moving the bit into drilling engagement with the sidewall of the drill hole. In the improvement of this invention, the hydraulic means for moving the bit into drilling engagement comprises a new flow restrictor valve. This flow restrictor valve has an orifice and a slender pointed rod for restricting the flow of fluid through the orifice. Opposing spring means and control fluid means engage the rod for controlling its movement toward and away from the orifice.

Abstract: This concerns a method of connecting a subsea flowline to facilities on top of an offshore platform which is supported above a body of water and which has a plurality of conductors extending from above the water to within the sea bottom. One of the conductors is cut just above the mud line and raised to leave a gap between the lower end of the upper portion of the conductor and the conductor stub which remains firmly anchored in the sea bottom. The flowline is pulled to a position just adjacent said conductor stub. A production riser is lowered through the upper portion of the conductor and then the lower end of the production riser is connected to the pulled end of the flowline.

Abstract: A releasing tool for use in disconnecting a casing or conductor pipe cemented below the marine floor from a riser pipe supported from a floating vessel in which the riser pipe and conductor are held together by a snap ring. This includes cam carrier connectable to the lower end of a longitudinal member, such as a drill pipe, and a releasing pin block carrying radially supported releasing pins which are urged inwardly. When the cam of the cam carrier is urged downwardly with respect to the releasing pin block it forces the releasing pins outwardly through ports in the latch pin of the casing to release the split rings from its engaging position.

Abstract: An apparatus for use in lowering casing strings or other parts from a floating unit to a subsea well which includes an expansion-type casing running tool employing extendible latches that have left-handed threads cut on their exterior for engagement with similar threads on the inside of the casing which is to be lowered. Tapered blocks are spring loaded for expanding the dogs into position and hydraulic pressure is used to retract the blocks thus disengaging the running tool from the equipment just lowered. If disengagement of the latches is not accomplished, the running tool can be removed from the casing by left-handed rotation.

Abstract: A novel way of maintaining a riser in the approximate center of a moon pool of a drilling barge operating in a shallow water. A single hydropneumatic cylinder is used to support the riser from the barge laterally at four points using a series of cables, sheaves, and a load cell.

Abstract: Drilling operations are run in a riser pipe, e.g., 20 inches in diameter, which extends from a ship to an anchored wellhead assembly on the ocean floor. Various strings of casing for lining the borehole wall are run down through the interior of the riser pipe. The first string of casing run is of relatively large diameter, e.g., 9-5/8 inches in diameter. Each successive string of casing which is run in this particular well is progressively smaller in diameter. Ideally, one would need a new and smaller riser in order to maintain about the same drilling fluid upward velocity. A high upward fluid velocity can be maintained by placing sleeve inserts in the annulus space between the drill string and the riser pipe interior wall. Additional strings of sleeves may be run inside the original sleeve to obtain a multiple effective sizing of the riser pipe.

Abstract: This invention relates to a structure floating on a body of water. Three or more spar buoy-type floats support the structure above the water. The structure is connected to anchors in the floor of the body of water by .[.elongated members such as.]. large diameter pipe .Iadd.for example.Iaddend.. There are no other anchoring connections in the system. Each spar buoy has a unique structure so that vertical forces and overturning moments on the floating structure are minimized. .[.The spar buoys have a buoyancy means having a volume of two parts..]. g The buoy of each spar buoy has a volume of two parts. The first part can be defined as resulting from a straight, vertical, prismatic shape which runs the entire vertical length of the .[.buoyancy means..]. .Iadd.buoy.Iaddend.. The volume of this prismatic portion comprises between about 40 and 80 percent of the total displacement. The .[.buoyancy means have a second or.]. .Iadd.second part has an .Iaddend.