Abstract: The current invention is directed toward the use of a downhole computer and downhole storage within a measurement-while-drilling (MWD) downhole subassembly to process data from the response of a plurality of sensors of different classes or one or more sensors of the same class which exhibit different measure points and vertical resolutions. Classes or types of sensors applicable to the invention include, but are not limited to, electromagnetic, acoustic, and nuclear. Sensor measurements are made essentially simultaneously. In combining downhole responses from one or more sensors to obtain parameters of interest, a critical prerequisite is downhole depth correlation and vertical resolution matching of all sensor responses prior to combination.

Abstract: A method and apparatus for identifying cuttings from a wellbore is disclosed. The cuttings can be identified by measuring emissions such as alpha, beta, or gamma particles which emanate from the cuttings. A continuous wellbore profile of the alpha or beta emissions can be constructed by measuring the emissions from cuttings taken from different locations in the wellbore, and by documenting such emissions. The effects of cuttings dispersion caused by differing particle sizes can be reduced by collecting cuttings of an intermediate size for analysis. The profile of the intermediate size cuttings can be compared with a well log to identify the original elevation of the cuttings within the wellbore.

Abstract: A closed loop vapor cycle refrigeration system an expander-compressor is disclosed. A portion of the liquid refrigerant in the system is expanded into gas. This gas is used to operate a compressor. The compressor compresses the low pressure gas from the evaporator and discharges the compressed gas either to a primary compressor or the condenser. A novel expander-compressor device is also disclosed for use in the refrigeration system.

Abstract: A closed loop refrigeration system utilizing an expansion device in the evaporation system is disclosed. In one embodiment, an expansion engine is connected to the evaporator inlet while a compressor is connected to the evaporator outlet. Liquid refrigerant flows through the expansion engine wherein it expands and drives the expansion engine. The compressor may be driven by the expansion engine or by a separate motor. A control circuit adjusts the refrigerant through the control valve in a manner which maintains a desired degree of superheat of the refrigerant leaving the compressor. In an alternate embodiment, the evaporator system has two evaporators. An expansion device is disposed between the inlet of the first evaporator and the outlet of the second evaporator. Partially subcooled liquid refrigerant from the first evaporator is passed into the second evaporator through an expansion valve wherein it evaporates into gas a refrigerant.

Abstract: A microprocessor controlled system for use in a refrigeration system which includes a plurality of pulse controlled solenoid flow control valves suitable for use as expansion valves is disclosed. A pulse width modulated control signal is generated for cyclically opening and closing the flow through the solenoid expansion valve. The duty cycle of the pulsed control signal determines the average flow rate through the valve. The microprocessor responds to the flow rate through each of the solenoid valves to determine, on a system-wide basis, if each fixture in the system, as indicated by the flow rate through the expansion valve associated therewith, is operating properly.

Abstract: The present invention provides a method for on-line real-time processing of processing navigational data for determining the location of sensor and receiver points in a navigational network having a number of different types of devices. Observations from these devices are obtained using a coordinate system that follows appropriate nominal sailing lines. Outlying observations are discarded using w-statistics for the observations. Any correlated observations such as compass azimuths are uncorrelated. The uncorrelated observations are then sequentially processed in an extended sequential Kalman filter, which provides the best estimate of the station coordinates. These estimated coordinates are then used to determine the location of the source and receiver points.

Abstract: The present invention discloses an apparatus for rotatably attaching a sensor to a cable. A cable mount having a groove about a substantial portion of its periphery is fixedly placed on the cable. A sensor mount having a key adapted to slide along the groove is rotatably placed on the cable in a manner which enables the key to remain in the groove when the sensor mount rotates about the cable.

Abstract: Doping the jacket of a data cable reduces the bulk volume resistivity of the jacket material allowing built-up static electricity to discharge. This reduces the likelihood of static charge interfering with data transmission.

Abstract: A twin-axial cable comprises a central core around which two conductors are helically wrapped. Interspersing a plurality of spacers between the conductors determines the relative placement of the two conductors on the core. A dielectric barrier encases the core, conductors, and spacers.

Abstract: A seismic energy source for producing pressure pulses is disclosed. The source contains a substantially symmetrical main chamber for storing compressed fluid. Two shuttles adapted to abut against each other are slideably placed around the housing to sealingly enclose the chamber. A separate control chamber for each shuttle is formed to urge its associated shuttle against the other shuttle when pressurized fluid is supplied to the control chamber. A separate firing chamber is formed for each shuttle between the shuttle and the housing. The firing chambers are activated by the fluid from the main chamber to simultaneously move both the shuttles away from each other to allow the compressed fluid to discharge from the main chamber into the surrounding medium.

Abstract: A control valve for use in geophysical surveying is disclosed. The valve contains a housing having a through bore intersecting with a fluid path. The fluid passes from an input port to an output port. A seat having recess thereof is placed in the fluid path in the through bore. A poppet assembly is attached to the through bore at the end opposite to the seat. The poppet assembly contains a poppet one end of which is adapted to match the recess and moveable in opposite directions by a motor. A decoder is coupled to the motor for causing the motor to turn in the desired direction. When the motor is turned in one direction, the poppet moves toward the seat and completely closes off the fluid path between the input and output ports. To open the valve, the motor is moved in the opposite directions to move the poppet away from the seat until the fluid path is open.

Abstract: The invention provides a floatation apparatus for maintaining a longitudinal object at a constant depth below the water surface in a body of water. Several airtight chambers are connected in a serial connection to form a string of air tight chambers. A one-way check valve is installed in the chamber at one end of the string while the other end chamber is connected to a nose piece. Air is continuously supplied to the check valve connected to the end chamber. A separate one-way check valve is installed between each pair of adjacent chambers in the string in a manner that air can pass between only in the direction from the air source to the nose member. The floatation apparatus is pivotaly connected to the longitudinal object at more than one place by means of parallel links.

Abstract: The invention provides a seismic transmitter source system which includes a floatation device that contains a plurality of air tight chambers in a serial connection. A separate one way check valve is placed between each adjacent pair of the chambers. Pressurized air is continuously supplied to an end chamber. The one-way check valves enable the air to pass to the remaining chambers in one direction. A transmitter subarray containing a plurality of spaced apart transmitters is suspended from the floatation device by means of severasl pivotly connected links. The front end of the transmitter array is connected to a point near the front end of the floatation device. During operation, the seismic transmitter source system is pulled from a tow point located at the front of the floatation device, pulling both the floatation device and the transmitter subarray in substantially a horizontal straight line position while maintaining the transmitter subarray at a near constant depth below the water surface.

Abstract: A method and apparatus for erecting and removing offshore structures including a jacket and a platform is disclosed. The system of the invention includes a platform-lifting unit, a jacket lifting unit, and a control unit. The platform-lifting unit includes a laterally and vertically movable truss member, which is hingedly connected to a barge with lifting beams, and a means for positioning the truss member at desired height and at lateral displacement above the barge. The jacket-lifting unit contains a ballast tank structure connected to a strong back that has a plurality of grappling members. The control unit contains all supporting and controlling systems for the other units. To remove the platform, the truss member of the platform lifting unit is moved underneath the platform, the truss is raised to exert force on the platform, the platform is severed from the jacket, and the platform is moved on top of the barge.