Abstract: A stable extreme pressure grease comprising a base oil, a soap and an EP agent, in the preparation of which excess soap is provided for reaction with the EP agent whereby the thickening effect of the remaining soap in the grease is retained.

Abstract: A method for continuous velocity estimation of seismic data uses non-linear signal matching. Common depth point trace data is examined at selected offsets and non-linear signal matching is performed to derive moveout information from which the RMS and interval velocities may be further estimated. Non-linear signal matching for selected offsets of each CDP trace gather functions to derive characteristic match curve data at selected depths or travel time intervals. The match curve data inherently contains moveout information that relates to energy velocities for the particular trace position. Derived velocity data for selected time depths may then be output across a line of survey.

Abstract: A process for converting sulfide ion present in a solution to innocuous, water soluble sulfur species is provided. The process basically includes the steps of contacting the sulfide ion with an oxidizing agent to oxidize it to the water soluble sulfur species and admixing a surface active agent with the solution in an amount sufficient to inhibit precipitation of elemental sulfur and to promote subsequent oxidation. To enhance the formation of the water soluble sulfur species and to speed up the reaction, the oxidation reaction is conducted under alkaline conditions.

Abstract: Produced oil and water from a waterflood operation are initially subjected to a rough separation step producing an oil stream and an oily water stream. The oily water stream is mixed with a high density solvent for the oil, and the resulting mixture is processed in a hydrocyclone to produce clean water and an oil-solvent stream. The clean water is reinjected as additional flooding water, and the oil-solvent stream is separated to produce an oil product and clean solvent which is recycled to the process.

Abstract: A method and logger apparatus for analyzing mud returns to determine the presence of formation hydrocarbons. The logger takes a gas sample from a gas trap formed in the mud return line, purges it of all non-helium gases either by condensing them or chemically reacting them out of the sample. The sample is then fed into a special helium mass spectrometer that identifies how much of each helium isotope (.sup.3 He and .sup.4 He) is present. This data is then fed to a correlator/computer and an isotope ratio calculated and monitored. A significant increase in this ratio is indicative of the presence of formation hydrocarbons. The computer uses additional input to track the sample vs its original downhole location to enable proper identification. The method and apparatus are particularly useful with oil-based drilling fluids.

Abstract: A mesophase pitch suitable for carbon fiber production is produced by heat soaking a heavy aromatic hydrocarbon feedstock at conditions such that a substantial part of the feedstock is converted to mesophase pitch. The mesophase pitch is separated from the heat soaked material by settling at a pressure higher than the pressure of the heat soaking step. In one embodiment, separate mesophase pitches having different properties can be recovered from the heat soaked feedstock.

Abstract: Properties of premium coke are improved by coking the feed at a temperature lower than the normal coking temperature and thereafter subjecting the coke to a heat soak at substantially the same temperature as the temperature at which the coke was formed.

Abstract: Permeability of a highly permeable zone in a subterranean formation is reduced by injecting an oil external emulsion of an aqueous solution of alkali metal silicate. Emulsion adjacent the well bore is broken by the application of microwave. Released alkali metal silicate then forms a plug of gel at this point, through contact with formation brines, which holds the rest of the emulsion in place until it breaks down and gels. In one aspect a second internal phase containing a gelation agent is provided to accelerate gelling.

Abstract: Permeability of a highly permeable zone in a subterranean formation is reduced by injecting into the formation a polymerizable material which expands on polymerization, and thereafter effecting such polymerization.

Abstract: A method and apparatus for drilling subsea wells in water depths exceeding 3000 feet (preferably exceeding 4000 feet). Drilling mud returns are taken at the seafloor and pumped to the surface by a centrifugal pump that is powered by a seawater driven turbine. A low-differential pressure rotating head seats in the upper tapered portion of the longitudinal throughbore of an upper stack package which is attached to the top of the blowout preventer stack and seals against the drill string as it is run in and out of the borehole. The method and apparatus of the present invention enable higher mud weights to be used than can be used in conventional techniques which allows kicks to be more easily controlled, fewer casing strings to be run, and overall drilling time reduced by up to 40%.

Abstract: A microwave-based emulsion treating system comprising a microwave energy source, a microwave applicator for treating an oil-water emulsion, a wave guide between the microwave energy source and the microwave applicator, a circulator in the wave guide, a separator vessel for receiving and separating microwave-treated emulsion, and means for removing an oily water phase from the separator, circulating it to a water load chamber on the circulator, and returning it from the water load chamber to the separator.

Abstract: A computer-implemented technique for dip filtering of seismic data whereby seismic data of a selected attribute in space and time coordinates is displayed in accordance with a 3-D illumination model such that the apparent angle of illumination of the data relative to an apparent viewing position is optimally adjusted to achieve best differentiation and display presentation of seismic dipping events, fault indications, excessive multiple indications, and the like. The method requires a perceptual view of a seismic section as a 3-D surface from which a vector of images can be derived. Thereafter, vector of images surface components are derived and, in accordance with a pre-determined illumination model, i.e. composed as a function of azimuth and elevation relative to a display, the vector of images of the seismic data are transformed to produce enhancing a specific eye view/illumination alignment.

Abstract: A long pipeline is constructed at an on-shore site and then launched into a body of water. A tension force is maintained on the pipeline during launching to hold the pipeline off the floor of the body of water.

Abstract: A method of placing a template on the seafloor beneath a floating vessel. The method comprises suspending the template beneath at least one sling-mounted pendant buoy and using a tow cable and restraint cable to position the template in a position generally centered beneath the vessel. An extendable support, such as a drill string, may be connected to a previously attached descent sling, control lines and buoy slings detached, additional ballast added as needed, and the template lowered to the seafloor.

Abstract: A process for separating upgoing and downgoing seismic wave events in a vertical seismic profile, and particularly for vertical seismic profiles wherein the seismic energy source is offset from the borehole in which seismic detectors are located in vertical spaced array. The process operates on two detector signals at a time (as S.sub.1 and S.sub.2) and is based on the concept that waves traveling in opposite directions have spatial derivatives of opposite sign. The derivative is approximated by the difference of the two signals which is time integrated to recover the phase. The resulting integrated difference signal I is then amplitude scale corrected and combined by addition or substraction with a signal S.sub.0 representing the sum of the two detector signals to form a succession of filtered signals which, when recorded in alignment in order of detector depths to form a vertical seismic profile preserves either the upgoing or the downgoing seismic events.

Abstract: A single leg tension leg platform is a semi-submersible structure moored at a deep water site by hybrid mooring consisting of a single tension leg or cluster of tendons attached to a central column and, optionally, a conventional spread mooring system. The central column is surrounded by peripheral stability buoyant columns symmetrically arranged and typically in number from about 3 to 8. All the vertical tendons are located in a tight cluster at the center of the platform. This means that the tendons no longer effectively restrain pitch/roll or yaw motion. The role of the tendon cluster is essentially the direct, stiff elastic restraint of heave and compliant restraint of horizontal offset. Pitch/roll response is controlled primarily by careful distribution of peripheral buoyancy and detuning.

Abstract: A perforating-gun spacer used to position a plurality of guns to perforate a multizone reservoir is formed of a plurality of telescoping sections which are held in an extended position by tapered pins. A slidable piston maintains the pins in engaged position. When the perforating guns are fired, the resultant pressure pulse in the wellbore fluid moves the piston upwardly out of engagement with the restraining pins which then disengage permitting the telescoping sections to collapse when the expended tool is dropped into the bottom of the wellbore. This avoids partial or complte blockage of the lowermost production zone by the upper portion of the perforating gun string.

Abstract: A tensioner system for a riser of a subsea production well. A plurality of at least three tensioners are each pivotally secured to both a lower surface of the production platform and to a tensioner ring that is itself secured to the riser. The tensioner ring may be generally octagonal with arms protruding from alternate faces of the octagon. These arms define the connecting points for the tensioners. The tensioners are angulated with respect to the axis of the riser, converging toward a single point lying on that axis and defining a first angle. The arms preferably form a second angle with respect to the body of the tensioner ring that is equal to said first angle so that the reaction surface defined by the bottom of the arms is perpendicular to the force lines along which the tensioners act. The failure of one of the tensioners will not result in unbalanced forces that could produce bending torsion, as occurred with previous designs.

Abstract: Disclosed is a low toxicity oil for use in drilling fluids. The oil consists essentially of branched- and cyclic-paraffins having 11 to 17 carbon atoms per molecule and further having a low aromatic content of less than about 1% and a low normal-paraffin content of less than about 5%. The low polynuclear aromatic oil is useful in both oil-based and water-based drilling mud, particularly where low toxicity and lack of water sheen are important such as in offshore drilling environments. The oil also has the advantage of being non-fluorescent so that it does not mask UV fluorescence of formation crudes produced from the drill cuttings in wildcatting operations.