Abstract: An acoustic receiver for sensing acoustic waves and generating orthogonal triaxial acoustic response data representative of said acoustic waves is disclosed. The receiver has at least four acoustic sensors oriented in at least four different directions. Each of the acoustic sensors is adapted to produce an electrical signal in response to an acoustic wave impinging thereon. The inventive acoustic receiver also includes means for combining the electrical signals to yield orthogonal triaxial acoustic response data. In one embodiment the means for combining the electrical signals comprises wiring the acoustic sensors in two series pairs to produce a combined output along two of the three orthogonal axes and orienting at least one acoustic sensor substantially parallel to the longitudinal axis of the acoustic receiver.

Abstract: An apparatus and method for installing a deck on an offshore substructure is provided. The apparatus comprises a deck supported by lifting mechanisms that are in turn attached to pontoons. The apparatus floats on the water with the lifting mechanisms compressed until transported to an offshore substructure having an upper end located above the water surface. The lifting mechanisms are then extended and the apparatus moved on the surface of the water to position the deck over the substructure. The deck is then lowered onto the substructure and the pontoons are lifted out of the water.

Abstract: An offshore structure which is resistant to wave, earthquake and ice loads and can be quickly installed and abandoned in response to changing environmental conditions includes a caisson having an upper section and a lower foundation section which are separated by a structural diaphragm. When installed, the lower foundation section extends downwardly a distance from the seafloor to provide sufficient lateral and vertical soil resistance to resist lateral and vertical loads on the structure. The upper section is adapted to support a deck structure. The structural diaphragm is adapted to rest on the seafloor when an offshore structure has been fully installed to enhance the lateral and vertical load carrying capacity of the offshore structure. During installation, the structural diaphragm and a pump are used to form suction in the lower foundation section, thus enhancing the penetration of the lower foundation section into the seafloor.

Abstract: A method for disposing of an offshore platform jacket comprises suspending the jacket in one piece under a tow vessel, towing it to the disposal site and safely and quickly releasing the jacket at the disposal site. Once the jacket foundation piles have been severed, the first end of the jacket is lifted using a derrick barge crane or winch connected to a first lift rigging device until the first lift rigging device engages with a first release device. The second end is lifted in a similar manner with a second lift rigging device and a second release device until the jacket is suspended substantially beneath the tow vessel. The lift rigging device include a spreader bar having at least one skid shoe attached thereto, at least two padeyes attached at opposite ends of the spreader bar, a lift sling attached to the padeyes and at least two jacket support slings. Each release device is attached to the tow vessel and includes at least one rocker beam having a connector.

Abstract: This invention provides a method for constructing an offshore platform by mating a self-floating deck structure with a self-floating substructure. The self-floating deck structure may be a floating pier or barge, on which the desired equipment has been mounted. Mating is achieved by at least partially submerging the substructure, positioning the pier or barge above it, and deballasting the substructure to create a vertical bearing force between the substructure and the pier or barge. Horizontal force may be transmitted between the deck and substructure by a variety of mechanical, structural, and magnetic means.

Abstract: A method for controlling the pressure at the base of a gas-lifted riser during casing installation is disclosed. Prior to casing installation, drilling fluid is displaced from the riser and the riser is filled with seawater. During casing installation, the riser base pressure is monitored, and the height of seawater in the riser is adjusted to compensate for increases in the riser base pressure. The riser base pressure is thereby maintained substantially equal to the seawater pressure at the base of the drilling riser throughout installation of the casing.

Abstract: A method is disclosed for installing a tubular member, having an upper end and a closed lower end, axially into and through an over-pressured region of the earth by using a mandrel to drive the tubular member from near the bottom, which results in a significant section of the tubular member being pulled through the over-pressured region. In another embodiment, a filler material is inserted into at least a portion of the tubular member, and the tubular member is driven from the upper end, with the filler material assisting the progression of the tubular member through the over-pressured region.

Abstract: An earthquake-compliant offshore platform for use in regions of strong earthquakes is disclosed in which the natural vibrational period of the jacket structure is preferably in the range of about 4 seconds to about 8 seconds, which is between the primary excitation period of earthquake energy and the primary storm wave period. The earthquake-compliant jacket structure is lighter than a conventional steel battered jacket for the same location and conditions and has a constant cross-section. The vibrational period of the earthquake compliant platform can be tuned by altering structural stiffness or mass.

Abstract: A method is disclosed for installing a tubular member, having an upper end and a closed lower end, axially into and through an over-pressured region of the earth by using a mandrel to drive the tubular member from near the bottom, which results in a significant section of the tubular member being pulled through the over-pressured region. In another embodiment, a filler material is inserted into at least a portion of the tubular member, and the tubular member is driven from the upper end, with the filler material assisting the progression of the tubular member through the over-pressured region.

Abstract: The invention is a rigid, hollow core, low-density ball sealer designed to perform effectively in hostile well environments. It temporarily seals perforations inside cased wells at temperatures up to 400.degree. F. (204.degree. C.), at hydrostatic pressures up to 20,000 psi (137 Mpa), and at differential pressures across the perforations up to 1,500 psi. Ball densities may range from 0.80 to 1.3 gm/cc (or higher). It can withstand the degradation effects of solvents common to oil and gas wells during a workover. Nominal changes in ball density occur during a 24-hour period when exposed to a hostile well environment. The ball sealer is comprised of two pieces made of a high strength material that snap together to form a hollow-core sphere. If necessary, adjustments to ball density can occur subsequent to manufacturing of the ball pieces.

Abstract: A process for separating solids from a fluid using at least one polymer and acoustic energy at or above cavitation is disclosed. The fluid containing the polymer is flowed into a vessel and acoustic energy is applied to the fluid at intensity sufficient to induce cavitation within the fluid. At least a portion of the solids are allowed to agglomerate in at least one position within the vessel. The agglomerated solids are then separated from the fluid.

Abstract: A non-upset tubing section, a tubular coupling, a connection for non-upset tubing sections, and a method for connecting the non-upset tubing section and the tubular coupling are disclosed. Methods for fabricating the non-upset tubing section and the tubular coupling are also disclosed. In one embodiment, the non-upset tubing section has an outer diameter of about 23/8 inches and, in another embodiment has an outer diameter of about 27/8 inches. The non-upset tubing section also has an externally tapered threaded surface having approximately eight rounded threads per linear inch. The tubular coupling has an outer diameter of about 27/8 inches, for use with at least one 23/8 inches OD tubing section, or about 31/2 inches, for use with at least one 27/8 inches OD tubing section. The coupling also has an internally tapered threaded surface having approximately eight rounded threads per linear inch and having a pitch diameter of about 2.258 inches for use with the 23/8 inches OD tubing section or about 2.

Abstract: A process for welding mechanically and/or thermally treated alloy pipes to achieve the full tensile capacity of the unwelded base alloy across the welded pipe joint is disclosed. The process comprises welding the pipes together at the beveled pipe ends to form a cap of weld metal. The weld metal cap overlaps that portion of the heat-affected zone which is created in the base alloy adjacent to the bevel of each pipe during welding. To further increase the tensile capacity of the welded joint, a low-heat buffer bead layer can be deposited on the outer surface of each pipe proximate the outer edge of each bevel, prior to depositing the weld metal between the bevels. The buffer bead layers serve to reduce the thickness of that portion of the heat-affected zone which is formed in the base alloy under each toe of the weld metal cap (upon formation of the weld metal cap) to a level having no significant reduction in the overall tensile capacity of the welded joint.

Abstract: A borehole mining process for recovery of petroleum from unconsolidated heavy oil formations. The process consists of drilling a borehole in the unconsolidated heavy oil reservoir, which is formed from sand particles aggregated by heavy oil, and positioning a casing and a first and second tubing string within the borehole. At least one nozzle is positioned on the lower end of the second tubing string and is oriented for fluid emission generally radially outwardly from the second tubing string. Fluid is then flowed downwardly through the second tubing string and outwardly through the nozzle, thereby eroding a cavity in the reservoir and forming a slurry consisting of the fluid, the heavy oil, and the particles from the reservoir. The slurry is flowed upwardly through the annulus between the first and second tubing strings to the upper end of the borehole for recovery of the heavy oil.

Abstract: A method for increasing the end-bearing capacity of an open-ended pile is disclosed. The method comprises first determining the quantity of granular material necessary to insure full mobilization of the available capacity of the soil at the tip of the pile. The granular material is then inserted within the pile on top of the soil column, thereby causing the column of granular material to plug or lock-up within the pile during transient loading and thus mobilize the available capacity.

Abstract: A sleeve for a seismic air gun exhaust chamber is disclosed. The sleeve prevents water from accumulating in the air gun exhaust chamber when the air gun is vertically positioned and provides a convenient method for regulating the volume of the air gun exhaust chamber, and thus the frequency of acoustic energy emitted by the gun. The sleeve is characterized by a false bottom which is connected to the main chamber by an orifice and passages.