Abstract: An icebreaking buoy system includes an icebreaking buoy connected to clump weight means positioned on the sea floor by a mooring line having minimum extra length sufficient to permit the buoy to ride up over the largest expected wave. Several such buoy systems may be used to form a line along one or more sides of, or a ring entirely around, an offshore structure or rig to break an ice sheet in the direction or directions it is moving. An anchor fixed to the sea floor may be connected to the clump weight means. Each buoy has a downward sloping bottom portion and a cylindrically or spherically formed top portion. The sides or ends and the bottom of the buoy may be beveled, conical or spherical.

Abstract: The present invention provides Ni (and/or Co) base precipitation hardened alloy compositions having improved resistance to stress corrosion cracking and being comprised of:12-25 wt. % Cr;0-10 wt. % Mo;0-12 wt. % W, with the proviso that Mo+0.5 W is .gtoreq.2 wt. % and .ltoreq.10 wt. % and with the proviso that Cr+Mo+0.5 W is .ltoreq.28 wt. %;2-6 wt. % of one or more of Al, Nb, and Ti;<0.05 wt. % C;<0.05 wt. % O;<0.05 wt. % N; and the balance being Ni (and/or Co) and any incidental impurities,wherein the concentrations of Ni (and/or Co), Cr and Mo (and/or W) are correlated so that their combination represents a point within the area ABCD of FIG. 1 hereof. Preferably, the ratio, expressed in atomic percent, of Al to Nb+Ti is between about 0 and 4.0, preferably between about 0.8 and 1.5, more preferably about 1. In addition, Hf is preferably included in a concentration, expressed in weight percent, of between about 10 (C+O+N) and 30 (C+O+N), more preferably between about 15 (C+O+N) and 20 (C+O+N).

Abstract: An improved method for placing ball sealers (25) onto casing perforations (17) in a deviated wellbore (10) is disclosed. In this invention, a plurality of ball sealers (25) are introduced into the casing and are transported to the perforations at an interface (26) between two immiscible fluids; the first or leading fluid (21) having a density greater than the ball sealers and the second or trailing fluid (24) having a density greater than the ball sealers.

Abstract: An acoustic logging apparatus and method are disclosed for determining the direction of a subsurface noise source, such as a blowout well or fluid channeling behind well casing. The apparatus comprises cylindrical piezoelectric crystal transducers processed to buck each other. The method employs such an apparatus and includes generating and observing output from the crystals. The direction of the noise relative to the position of the apparatus is indicated by determining the position of the crystal transducers when their phase and amplitude differences are at a minimum. The transducer leading in phase at a point perpendicular to said position is the transducer closest to the noise source and is used to indicate the absolute direction of the noise.

Abstract: A marine cable system including one or more elongated cable sections whose buoyancy may be independently controlled. Each section is associated with a pump and a variable volume, elongated bladder. In one embodiment, one reservoir containing buoyant fluid is included, and fluid from the reservoir is pumped between adjacent sections to inflate or deflate the associated bladders. In another embodiment, a rigid reservoir containing compressed gas is included in each section. The associated pump releases gas from the reservoir to inflate the bladder, or pumps gas from the bladder into the reservoir when desired. The pumps are operated in response to control signals from a remote control unit, such as one aboard a vessel towing the cable. One or more depth sensors may be attached in or near each section. Depth information from the sensors may be supplied to the control unit for use in generating the pump control signals. The buoyant fluid is entirely contained within the cable.

Abstract: Method and apparatus for digitally deriving arrays from seismic data. Indentical parallel processing elements connected between common input/output buses are each preselected to derive different pluralities of arrays. Array specifications defining the arrays are downloaded into the processing elements. A scan sample set of spatially distributed seismic receivers is periodically generated and placed on the input bus. Each processing element, in response to array specifications, captures and stores all receiver output signals in the scan required to derive its respective arrays, derives its assigned arrays, and delivers resultant array samples to the output bus. Double input and output buffering in the processing elements is provided whereby receiver capture, array derivation, and outputing processes occur simultaneously in each processing element.

Abstract: An apparatus for detecting substantially longitudinal flaws in the end area of a tubular member is disclosed. The apparatus comprises magnetizing-detection units, means for moving-said units along a helical path about the surface of the end area of the tubular member, and means for centralizing and securing the apparatus on the end of the tubular member being inspected. Magnetic detection transducers on the magnetizing-detection units detect perturbations in the applied magnetic field in the area of any substantially longitudinal flaws. The magnetic detection transducers are mounted so as to remain remote from the surface of the tubular member during operation of the apparatus. The field is generated in the tubular member by said magnetizing-detection units. The magnetizing-detection units are pivotably mounted to allow for movement over both flat and tapered surfaces. The signals generated by the magnetic detection transducers are transmitted to an external indicating device through slip rings.

Abstract: Apparatus for simultaneously rotating and reciprocating well pipe mechanically utilizing the rotary table on the drilling rig includes a rotating pipe clamp assembly having an irregular cross-sectional mid-member and clamp members for releasably gripping the well pipe connected to the ends of the mid-member for rotation therewith; a square block for fitting the rotary table square and having a selected groove configuration; and a torque transmitting means fitting into the groove and having openings there-through having the same irregular cross-section as said mid-member cross-section. Means connects the torque transmitting means and the block for limiting torque applied to the well pipe via the clamp assembly and the torque transmitting means.

Abstract: A remotely-controllable, surface-referenced paravane for use in towing an object in a body of water at a controlled lateral offset from the pathway of the towing vessel is disclosed. The principal components of the paravane are a buoyant hull, a cambered hydrofoil shaped keel attached to the bottom of the hull and extending generally downwardly into the body of water, a remotely-controllable steering means, and a tow cable which connects the paravane to the towing vessel. Passage of the cambered hydrofoil shaped keel through the water generates a lateral force, similar to the lift generated by an airfoil, which causes the paravane to move laterally away from the pathway of the towing vessel in the direction of the lateral force. The remotely-controllable steering means is used to compensate for changes in the speed of the towing vessel or variations in wind, waves, or currents so as to maintain the lateral offset of the paravane within certain limits.

Abstract: A compliant offshore structure in which stabilization against excessive sway is provided by a resilient pile assemblies. A series of drive piles extend into the ocean floor beneath the base of the structure. Drive piles extend upward to a position proximate a pile attachment location on the structure a spaced distance above the ocean floor. The upper end of each drive pile is secured to the structure at the pile attachment location by a resilient coupling. The resilient coupling permits the structure to move upward and downward a slight distance relative to the substantially rigid drive pile. This accommodates sway of the structure. The resilient coupling biases the structure back to a vertical orientation in response to sway of the structure. In a preferred embodiment the pile attachment location is situated proximate the base of the offshore structure.

Abstract: An underwater cryogenic pipeline system comprising an insulated underwater pipeline in an integral open frame is disclosed. The pipeline is anchored to the frame at a plurality of spaced apart locations. Bellows-type expansion joints between the pipe anchors compensate for contraction in the pipeline. The frame, which is anchored to the soil at at least one location, resists axial forces in the system and wave and current loadings. The system is preferably fabricated in modules and assembled on site.

Abstract: A flexible structural joint of "flex joint" for use in an articulated structure is disclosed. The articulated structure has a first section and a second section which are located along a longitudinal axis of the structure, the first section being subject to lateral or transverse loads. The flex joint is located between the first and second sections and accommodates lateral pivoting of the first section with respect to the second section through elastic flexing or bending of certain of its members. No moving parts are used. In a first embodiment, the flex joint consists of an elongated axial load member and at least three shear and torsion links oriented so as to lie substantially in a plane perpendicular to the longitudinal axis of the structure. Each of the links is connected at one of its ends to the first section and at its other end to the second section.

Abstract: Plugging perforations in casing in a wellbore penetrating a subterranean formation using degradale ball sealers. The ball sealer used is composed of a polyester polymer which is substantially insoluble in the wellbore fluid. The polymer degrades in the presence of water at an elevated temperature to form small molecules which are soluble in a fluid in the subterranean formation. After the polymer degrades, the flow through the perforation returns to substantially its initial value.

Abstract: A coiled baffle system, primarily for conducting well treating operations, is disclosed. The baffle system preferably comprises a baffle which is inserted into a tubing within a well bore to segment the tubing into a high pressure conduit and a low pressure conduit. The baffle system of the present invention may also be provided with electrical conductors for attachment to a variety of subsurface tools or sensors.

Abstract: A method for determining the position of a subterranean plane reflector relative to a known location on the earth surface from unprocessed seismic data received at a number of colinear acoustic receiver locations. A traveltime curve associated with the reflector is identified from the seismic data. From two points on the traveltime curve, a signal indicative of the reflector's dip angle is generated. Using the dip angle signal, signals indicative of the position of each imaged point of the reflector are generated. The inventive method assumes knowledge of the average velocity of seismic waves in the subterranean formation above the reflector, and that such formation region can adequately be considered to have constant velocity equal to such average velocity. The method may be applied to process raw data generated during a vertical seismic profiling operation.

Abstract: A coupling 10 for connecting an elongate first member 12 to a second member 14. The first member 12 is provided with external radial fins 16. The second member 14 defines a recess provided with a number of internal radial fins 20. The first and second members 12,14 and their fins 16,20 are sized such that the first member 12 can be positioned within the recess of the second member 14 with each fin of each member extending between two corresponding fins of the other member. At least one wedge 24 is positioned in the space intermediate each set of opposing fins 16,20. The fins 16,20 and wedge 24 are configured such that biasing the first member 12 in a first axial direction relative to the second member 14 causes the wedge 24 to lock the fins 16,20 together, preventing movement of the first member 12 in the first axial direction. The present coupling 10 can be used to support the members 12,14 under either a tensile or compressive axial loading.

Abstract: An acoustic logging apparatus and method are disclosed for determining the direction of a subsurface noise source, such as a blowout well or fluid channeling behind well casing. The apparatus comprises cylindrical piezoelectric crystal transducers processed to buck each other. The method employs such an apparatus and includes generating and observing output from the crystals. The direction of the noise relative to the position of the apparatus is indicated by determining the position of the crystal transducers when their phase and amplitude differences are at a minimum. The transducer leading in phase at a point perpendicular to said position is the transducer closest to the noise source and is used to indicate the absolute direction of the noise.

Abstract: The present invention provides an approach for drilling offshore arctic wells in areas covered by floating ice. A grounded spray ice drilling structure having an inner drilling platform portion and an outer barrier portion which are contiguous is constructed by withdrawing water from beneath the ice sheet and spraying the water through the air when the air is below the freezing temperature of the water. This causes the water to freeze into spray ice as it passes through the air. The resulting spray ice is deposited on the ice sheet to build up the grounded spray ice drilling structure. The outer barrier portion is built up to a greater freeboard than the inner drilling platform portion, and is adapted to laterally confine the inner drilling platform portion and to protect the inner drilling platform portion from natural ice forces.

Abstract: An acoustic well logging method employing a tool having at least two acoustic transmitters and at least two acoustic receivers. In a preferred embodiment, one receiver is positioned midway between the two transmitters, and the other receiver is spaced from the first receiver along the longitudinal axis of the tool between the transmitters. Two signals, each representing an acoustic wave that has propagated from a transmitter through a portion of the formation surrounding the borehole to a receiver, are recorded when the tool is in each of two positions relative to the longitudinal axis of the well. In each of the tool positions, one recorded signal is associated with the midpoint receiver and the other with another receiver. From the four recorded signals, a new signal is generated. This derived signal has Fourier amplitude spectrum indicative of the formation parameters, but is independent of components associated with the transmitters and receivers.

Abstract: The present invention is an improvement to conventional baseplates for imparting seismic energy to an earth formation. A baseplate typically has a plurality of downwardly disposed triangular prism-shaped cleats for engagement with the earth surface above an earth formation under seismological investigation. At least one leaf spring is supported about midway along its length from the lower surface of the baseplate and between the cleats. An elongate horizontal ejector member is slidably interconnected to the respective ends of the spring. In operation, as the baseplate is lowered into engagement with the earth surface the ejector member is moved upward and the leaf spring is compressed. When the baseplate is lifted upward the restoring force of the leaf spring results in a generally downward force against the ejector member.