Abstract: An articulated, compliant offshore structure having a base portion establishing a gravity-type foundation on the ocean bottom, a tower extending upward from the base portion and a deck seated on the tower a spaced distance above the ocean surface. The tower is secured to the base portion by an articulated joint which permits the tower and deck to undergo limited pivoting about the base. This provides compliancy in response to forces imposed on the structure by wind, waves and ocean currents. A set of tensioned members, preferably cables, are secured between anchorages on the base and at an elevated position on the tower to provide controlled resistance to pivoting of the tower. In the preferred embodiment the tower and base are concrete shell structures.

Abstract: A complaint offshore platform in which the primary restoring force to lateral displacement is established by flex piles driven into the seafloor and fixedly secured to the platform legs a preselected distance above the seafloor. The platform includes a substantially rigid space-frame structure extending from the ocean bottom to a position above the ocean surface. A drilling and production deck is secured atop the space-frame structure. Shear piles extend through the base of the space-frame structure to prevent lateral displacement of the base while permitting the space-frame structure to pivot about its base. As the platform sways about its base in response to environmental forces, the flex piles establish a vertical couple at the location at which they are attached to the space frame structure. This couple resists movement of the platform away from a vertical orientation. In the preferred embodiment, the flex piles are secured to the platform at or near one-half the total height of the space-frame structure.

Abstract: A pile assembly adapted for use in a compliant piled tower. A plurality of drive piles are driven into the ocean floor in a symetric array about a central, substantially vertical axis. A flex pile is secured to the upper end of each drive pile and extends upward to a preselected elevation above the ocean floor. The longitudinal axes of each drive pile flex pile pair are laterally offset from one another with the flex piles also being arranged in symetric array about the central axis. A tie member is provided to restrain the flex piles from lateral motion relative to one another. The tie member serves to balance the moments established by virtue of the eccentric axes of the flex pile drive pile pairs. The use of eccentric axes in the pile assemblies simplifies driving the drive piles, permits the drive piles to be placed relatively far from one another to minimize pile group effects and permits the flex pile to be designed without being constrained by driving considerations.

Abstract: A method useful in seismic data processing for correcting data for the effects of the low velocity layer. At least three sets of traces having common offsets are displayed as a function of centerpoint. From this, the first refraction arrival for each trace may be hand picked, this first refraction arrival representing a compressional wave refracted along the lower boundary of the low velocity layer. An equation is set up for each source-receiver pair in which the transit time of the first refraction arrival is a function of three independent factors: the source to receiver distance; a low velocity layer component for the source; and a low velocity layer component for the receiver. These equations are solved in a simultaneous, least squares fashion to yield surface consistent solutions to the low velocity layer component at each source and receiver location.

Abstract: A method for preparing a display of seismic data obtained from multiple-point coverage of a subterranean earth formation using an array of seismic sources and acoustic receivers. A set of seismic traces is obtained in such a manner that each trace is associated with a source-receiver pair separated by a particular offset distance, and all the traces are associated with a common subsurface reflection point. Each of the traces is filtered through a bank of band-pass filters to produce a set of filtered traces, each having a different frequency content, for each offset value. The filtered traces associated with a particular offset value are displayed in order of progressively changing frequency content, and the filtered traces associated with a particular frequency band are displayed in order of progressively changing offset value.

Abstract: Method and apparatus for acoustic wave generation and transmission into a subsurface earth formation, particularly adapted for use in borehole shear wave logging. A logging sonde adapted to be suspended in a borehole traversing a formation houses a source of acoustic waves. The source simultaneously generates a plurality of acoustic waves propagating generally radially outward from locations within the sonde housing adjacent the vertical central axis thereof and will interfere to produce multipole acoustic waves in the formation. Detector means within the housing spaced longitudinally from the source detect acoustic energy in the formation resulting from the generated waves. In a preferred embodiment, the source includes a cross-shaped rod assembly comprised of two rods perpendicular to each other and joined at their mid-points through which the central axis passes.

Abstract: A method is disclosed for concentrating surfactant in an aqueous solution. The method comprises adding to the solution a component incompatible with the surfactant, such as a water-soluble polymer, thereby displacing the surfactant from the aqueous phase of the solution. The component remains in the aqueous phase and the surfactant goes into a surfactant-rich phase. The surfactant-rich phase can then be separated from the aqueous phase by conventional separation devices or techniques. This method is particularly applicable to concentrating surfactant recovered from a reservoir following an enhanced oil recovery process employing surfactant. The method may be practiced in the field or off-site.

Abstract: A perforator for perforating a subsurface formation surrounding a well bore to ensure perforation of channels in a cement sheath surrounding a casing pipe cemented in said well bore comprising a series of stacked plates, each plate containing spaced apart co-planar, pie-shaped linear charges and a co-planar, pie-shaped non-charged spacer arranged between each of said linear charges. There are preferably four linear charges and four non-charged spacers forming each plate. The linear charges on each plate are spaced angularly from the linear charges on each other plate so that the linear charges are aimed at different angular portions of the bore hole.

Abstract: A method of reducing the permeability of an area of a subterranean formation is disclosed. An alkali metal silicate foam is produced by injecting into the formation a solution of alkali metal silicate and a chemical surfactant, and a non-condensible gas. The foam hardens into a substantially impermeable solid. The foam may be used to reduce permeability in areas of the formation which have been steam swept during steam stimulation cycles. Thus, subsequent steam stimulation cycles will be directed to uncontacted areas of the formation.

Abstract: Hardfacing the principal bearing surface of a drill pipe with an alloy having the composition of: 50-65% Cobalt, 25-35% Molybdenum, 1-18% Chromium, 2-10% Silicon and less than 0.1% Carbon reduces the friction between the drill string and the casing or rock. As a result, the torque needed for the rotary drilling operation, especially directional drilling, is decreased. The alloy also provides excellent wear resistance on the drill string while reducing the wear on the well casing.

Abstract: The present invention relates to a flowline swivel. The swivel is configured so that the product seals are easily replaceable, the included bearing are not exposes to contamination either during use or during replacement of the product seals, and the seal surfaces may be cleaned without disturbing the bearings. The swivel incorporates removable product and environmental seal surfaces.

Abstract: A spacer comprising the water-in-oil emulsion portion of a shear-thickening well control fluid is used to separate drilling mud from the shear-thickening fluid in the drill pipe in the well bore to avoid premature thickening of the shear thickening fluid in the drill pipe. The shear-thickening well control fluid comprises a water-in-oil emulsion in which is dispersed granular particles of hydratable, water expandable clay.

Abstract: Ball sealers comprising a solid core coated with a polyurethane elastomer are introduced into a well to seal well perforations and divert fluid therein. In the preferred embodiment the ball sealers are used in a hydrocarbon liquid treating fluid and have a density less than the treating fluid.

Abstract: An injection assembly includes a packer set in the casing adjacent to the producing zone, having a bore sized to receive production tubing. A portion of the assembly suspended from the string of production tubing includes a side pocket mandrel, a twin flow head, an extensible telescoping housing, and coacting joint means on the extensible housing and the packer for axial joining of these members. The side pocket mandrel, twin flow head, and twin flow converter provide a first passage joined to the production tubing; and a length of inner tubing joined to the twin flow converter extends this passage down into the bore of the packer.

Abstract: Disclosed herein are improvements in a recoil reducing system of a gas gun which create pulses in a liquid medium by introducing therein gas under high pressure. The release of high pressure gas from the barrel of such a gas gun causes recoil of the barrel. To reduce recoil, a reaction plate is attached to the barrel by metal rods so that the high pressure gas will impinge upon the reaction plate before escaping into the medium, and the force exerted on the reaction plate by the impinging gas will at least partially balance the force of recoil. In a preferred embodiment of this invention, a layer of shock absorbent material is interposed between the reaction plate and the impinging gas to absorb some of the energy of the gas. Flexing of the metal rods is thereby reduced and the life of the rods is extended. Alternatively, the flexing of the rods is reduced by connecting each rod to the reaction plate through a chain link type of connection comprising two rings, each ring passing through the other ring.

Abstract: A thermal method is disclosed for recovering normally immobile oil from a tar sand deposit. Two wells are drilled into the deposit, one for injection of heated fluid and one for production of liquids. Thermal communication is established between the wells. The wells are operated such that heated mobilized oil and steam flow without substantially mixing. Oil drains continuously by gravity to the production well where it is recovered.

Abstract: There is disclosed a universal joint for multiple conduit system wherein all of the conduits pass through the interior of the joint. The conduits which pass through the universal joint on axes offset from the pivot axes of the joint are provided with first and second pivot means which are preferably fluid swivels. The fluid swivels provide the requisite flexibility to the conduits when the universal joint is flexed.

Abstract: Additional amounts of crude oil are recovered from a subterranean formation by flooding with a translucent emulsion comprising an upper- or middle-phase microemulsion as an external phase and a polymer-containing brine solution as an internal phase. The translucent emulsion tends to coalesce into its component phases under conditions of no shear, but is stabilized by low shears such as those imposed on fluids flowing through a subterranean formation.

Abstract: An improved offshore arctic structure is disclosed which controls the horizontal forces exerted by impinging ice masses. The structure includes lesser sloped wall sections near the sea floor and steeper sloped wall sections near the water surface. Thus, the deep pressure ridges contact the lesser sloped wall sections and the shallower ice sheets contact the steeper sloped wall section. The slope of all wall sections is chosen so as to keep all horizontal loads due to impinging ice masses below a preselected design maximum.

Abstract: A method for snubbing or restraining a cable. A cable is threaded through a sleeve which has brush bristle-like elements extending from the sleeve wall inwardly towards the center of the sleeve. The ends of the bristle-like elements are placed in contact with the surface of a portion of the cable and the frictional force resulting from the movement of the cable in contact with the bristle-like elements restrains movement of the cable through the sleeve.