Abstract: A tool for installing a flexible impeller within a water pump includes a sleeve having a diameter smaller than an initial diameter of an impeller in a relaxed state, a support extending about an end of the sleeve, and a translation assembly engaged with the support and configured for translating a pushing surface of the translation assembly. In operation, an impeller is contracted into a constrained state and placed in the sleeve, the sleeve is then positioned proximal or in engagement with an opening of the water pump, and the translation assembly is translated such that the pushing surface pushes the impeller into the engine assembly as the translation assembly is translated.

Abstract: Stands (43) of multiple lengths of drill pipe, for oil and gas drilling are individually supported in a storage bin (28, 29) in an array of plural layers of plural numbers of stands. The individual stands are held in cooperating notches (41, 42) in vertically aligned support sleepers (38, 39) so that each stand experiences loads due only to its own weight and motions of a bin frame (13) where, as preferred, the frame is supported on a drillship deck (12). Sleepers between stand layers are indexable between positions in the array and outside the array. A bridge crane (32, 33) spans the length of the bin and is moveable transversely above it. The bridge crane carries vertically movable magnetic lifting heads (47) for lifting, holding and releasing an individual pipe stand. The crane can move a stand between a supported position in the bin array and a supported position on a power-driven carriage (18, 49) which is movable along a path along an upper part of a side of the bin (28, 29).

Abstract: For the safety and convenience of personnel working on upper portions of a blowout preventer stack (10), a work platform (25) is supported at the midheight of the stack. The platform has a main support structure (26) which is affixable to central connection flanges in the stack. Auxiliary support members (33) are releasably affixable to arms (27) of the main structure, and to them are releasably affixable separate personnel support deck units (38). Guard rails (42) can be connected to the deck units. The platform is modular for easy mounting and demounting to the stack. The platform's main support structure (26) can be a long term element of the stack if desired.

Abstract: A floating marine structure, such as a drillship (10 ) includes at least one thruster (14, e.g.) which includes a thruster head (22) having a propeller (102) which is adjustable to vary the angular relation to the drillship hull (11) of the horizontal direction of thrust produced by operation of the thruster. The thruster includes an enclosure (23) above the propeller for a propeller drive motor (49). The thruster has a deployed position in which the propeller (102) is submerged below adjacent exterior surfaces of the hull. The thruster is retractable vertically into the hull to retracted position where the propeller is below the floating waterline (50) of the hull. Further, the thruster has a more elevated service position to which the thruster is movable vertically from its retracted position.

Abstract: A jackdown tension leg platform is set forth which may be used for processing a commodity liberated from the ocean floor by one or more wells. The platform includes a closed buoyant hull which houses production equipment and at least one connector disposed on the hull for vertical relative movement. The connector has one end secured to the ocean floor and is moved upwardly relative to the hull to submerge the hull to a depth below the majority of the ocean's hydrostatic forces and, at the same time, tension the connector to hold and stabilize the hull over the wells. Conduits are connected between the wells and the submerged hull and between the hull and the surface. A crew module may be provided above the surface atop the connector with a trunk disposed between the module and submerged hull to provide access therebetween.

Abstract: A submerged tubular tower 10 is connected at its lower end 15 to an ocean floor 11 at a site where at least one subsea hydrocarbon well is to be drilled. A riser duct 22 for each well to be drilled extends from an upwardly accessible connection point 20 at the upper end 14 of the tower to the lower end of the tower. The tower is positively buoyant to stand erect in an unguyed manner. The upper end of the tower is located a substantial distance above the ocean floor at a depth sufficiently small to enable wells to be drilled through the riser ducts, through equipment 19 landed on the top of the tower, using floating drilling equipment 12 designed for use in substantially shallower water depths.

Abstract: A gravity-type offshore structure, useful as an offshore drilling platform, e.g., is provided for use in ice-covered waters such as offshore of the Alaskan and Canadian North Slope. The structure is composed of a plurality of floatable and controllably ballastable modules, each of which can be fully submerged. The modules are stackable by selective ballasting and deballasting operations in a suitable sequence to define a mobile offshore structure. The structure is assemblable adjacent a site of use and is floatable after assembly to, from and between successive sites of use. At each site of use the assembled structure is ballasted by sea water to be supported by the sea floor and to have sufficient deadweight, in combination with its support by the sea floor, to stand against ice loads urging the structure laterally of the site. Major ones of the modules preferably are constructed of reinforced concrete arranged within the modules in a honeycomb cellular fashion.

Abstract: A development and production facility for an offshore oil or gas field is constructed and drilling of wells is performed using a jack-up drilling platform in an improved manner. The facility is composed of a development well platform and a production platform, each of which is composed of a modular prefabricated unitary deck assembly of substantially turn-key completeness and of a prefabricated jacket or leg assembly to which the deck assembly is matable. Crane or derrick barges are used only to position the deck assemblies on the leg or jacket assemblies after the latter assemblies have been placed erect on and secured to the sea floor by use of the jack-up platform. The development well platform is constructed first so that drilling of development wells can be performed from the jack-up platform through the former platform concurrently with the placement and completion of the production platform.

Abstract: A hydraulic fluid comprising at least one polyethoxylated fatty amino carboxylate zwitterion. Preferred compositions contain polyethoxylated fatty amines and fatty amino carboxylates. Fatty acid quaternary ammonium salt-based biocides, polyethoxylated fatty amino corrosion inhibitors, polyhydroxy alcohol freezing-point depressants and dispersants may be included. Concentrates of the compositions and their method of preparation are disclosed.

Abstract: A tension-leg offshore platform comprises a positively buoyant, floating upper unit in which an operations platform is supported above an ocean surface by a plurality of spaced vertical columns defining buoyancy chambers. The lower ends of the columns are connected to the ocean floor by a corresponding plurality of tension-leg assemblies. Each tension-leg assembly is comprised of a plurality of positively buoyant tubular members having their lower ends connected securely against upward movement to the ocean floor. The tubular members are of substantially equal length less than the pertinent water depth by an amount adequate to cause their upper ends to be located below the area of significant surface wave action yet substantially above the ocean floor. A separate flexible tension member for each tubular member connects the lower ends of the columns to the upper ends of the corresponding tubular members.

Abstract: A mobile offshore platform has a buoyant and ballastable mat base of substantial horizontal extent. A cylindrical pylon is fixed to and extends upwardly from the center of the base. The pylon has a height greater than the maximum operating water depth of the platform. A positively buoyant deck unit has a central opening through it within which the pylon cooperates. The deck unit is movable vertically along the pylon in response to the operation of jacking mechanisms and cooperating jacking legs located adjacent the corners of the deck unit. The jacking legs are engageable at their lower ends with the base whereby operation of the jacking mechanism causes the deck unit to be moved vertically along the pylon relative to the base. In use, the deck unit is elevated to the top of the pylon after the base is submerged into contact with a sea floor and the jacking legs are thereafter disposed in a retracted position with their lower ends adjacent the deck unit.

Abstract: An air cushion vehicle has a plenum structure surrounding the vehicle body and a plurality of skirt segments. Each segment is attached to its own rigid frame which supports a flexible membrane. The frame outer end pivots from the plenum structure, while the frame inner end can move upwardly relative to the vehicle body from an inclined deployed position to a horizontal retracted position. The skirt membrane is extended from the frame during hovering and can be furled to its frame for replacement. The skirt segments are replaceable from inside the vehicle's air plenum.

Abstract: There is provided an apparatus for measuring linear movement of an ice mass on a body of water. The apparatus comprises two stationary anchors on the floor of the body of water. Two sheathed cables attached to the anchors extend from the anchors through a downtube in the ice mass to spring-loaded reels located above the ice mass. The spring-loaded reels are coupled to multi-turn potentiometers. The downtube comprises a pipe and two cable guide structures disposed therein. The guide structures are oil filled to afford smooth axial movement of the cables through the downtube as the ice mass and the downtube carried thereby move relative to the anchors.

Abstract: A concrete offshore structure located in a body of water of selected depth and extending from a bed defining the bottom of the water body to above the water surface comprises at least two similar prefabricated concrete modular subassemblies interconnected in a vertical arrangement in such manner to define a horizontal interface between each such pair of subassemblies. vertically disposed shear resistant pin means between the subassemblies and cement at the interface secure them together.A method for deploying such a structure includes towing the subassemblies offshore, mating them, and towing the assembled structure to the selected offshore installation site.

Abstract: Apparatus and method are provided for handling guidelines for an ocean drilling platform rig. A cart for guiding the lines rides on a track and can be moved away from a drill well when a blowout preventer is moved into place over the well on its own cart. When the load of the blowout preventer is transferred to a drilling string, the blowout preventer support cart is moved away from the drill well and the guideline handling cart is positioned over the well. The guidelines are then attached to a guideline frame on the blowout preventer.

Abstract: A cylindrical stress sensor has a case that is long relative to its diameter. The case may be completely imbedded in the body of a host material in which a change of stress is of interest. That portion of the sensor which is imbedded has a rounded end. The rounded end, circular cross section, and relatively large length-to-diameter ratio avoid errors occasioned by stress concentration. A strain transducer of a vibrating wire excited by a magnetic coil is located remote from any imbedded end of the sensor. Changes in strain on the wire alter the frequency of the wire. This change in frequency is picked up by the excitation coil as a signal. A stacked, three-transducer array, with the wire of each transducer at 45.degree. from a neighboring transducer, can detect changes in the magnitudes and directions of the principal stresses, without first establishing the direction of the primary or secondary principal stress.

Abstract: An ocean thermal energy conversion facility includes a long pipe assembly which is supported at its upper end by the hull of the floating facility. Cold water flows to the facility from deep in the ocean. The pipe assembly comprises an elongate pipe construction and a weight connected to the lower end of the construction by a line of selected length. A floatation collar is connected to the construction at its upper end to cause the construction to have positive buoyancy and a center of buoyancy closer to the upper end of the construction than its center of mass. The weight renders the entire pipe assembly negatively buoyant. In the event that support of the pipe assembly should be lost, as by release of the assembly from the facility hull in an emergency, the assembly sinks to the ocean floor where it is moored by the weight. The pipe construction floats submerged above the ocean floor in a substantially vertical attitude which facilitates recovery of the assembly.

Abstract: Apparatus is provided for connecting to a floating structure the upper end of a pipe assembly disposed substantially vertically in an ocean and the like. The pipe can be an upwelling pipe in an ocean thermal energy conversion installation. Gimbal apparatus are coupled between the pipe and the structure concentrically about the pipe. The gimbal apparatus define two orthogonal gimbal axes about which the pipe can move relative to the structure. The gimbal apparatus carry essentially all of the load between the pipe and the structure. Ball joint apparatus are coupled between the upper end of the pipe and the structure to define the boundaries of a path of fluid flow between the pipe and the structure. The ball joint apparatus includes an element associated with the pipe and an element associated with the structure. The ball joint apparatus is centered in the intersection of the gimbal axes.

Abstract: Apparatus is provided for connecting to a floating structure the upper end of a pipe assembly disposed substantially vertically in an ocean or the like. The pipe can be an upwelling pipe in an ocean thermal energy conversion installation. A downwardly open, elongate hollow socket is connected to the structure, and a mating elongate hollow pin member is connected to the upper end of the pipe assembly. Mating of the pin member in the socket requires only upward linear motion of the pin into the socket. Separate tethers are connectible in parallel to the pin and socket between the pipe assembly and the floating structure for holding the pin member in mated engagement with the socket. The tethers are severable for releasing the pipe assembly, which is negatively buoyant, from the floating structure in the event of an emergency or otherwise.

Abstract: An ocean thermal energy conversion facility includes a long pipe assembly which is supported at its upper end by the hull of the floating facility. Cold water flows to the facility from deep in the ocean. The pipe assembly comprises an elongate pipe construction and a weight connected to the lower end of the construction by a line of selected length. A floatation collar is connected to the construction at its upper end to cause the construction to have positive buoyancy and a center of buoyancy closer to the upper end of the construction than its center of mass. The weight renders the entire pipe assembly negatively buoyant. In the event that support of the pipe assembly should be lost, as by release of the assembly from the facility hull in an emergency, the assembly sinks to the ocean floor where it is moored by the weight. The pipe construction floats submerged above the ocean floor in a substantially vertical attitude which facilitates recovery of the assembly.