Abstract: Compact, lightweight, rotating eccentric weight seismic sources and a seismic exploration method particularly suitable for use in relatively inaccessible onshore regions. The source includes an eccentric weight rotatable about an axis and a sensor to detect the instant of peak earthward force developed by the source. A coded energy signal is transmitted into the earth and the seismic waves returned from within the earth are detected. The polarity of a signal proportional to the seismic waves is periodically sampled to produce a plurality of sign-bit samples. The sign-bit samples are automatically shift-summed in response to a code signal generated by the sensor, thereby forming a plurality of shift-summed samples which are recorded to provide a correlated seismic trace.

Abstract: A high temperature cement system including a carbon-containing, low volatile material additive admixed with cement in proportions sufficient to provide a fixed carbon content of at least 0.02 weight percent. Additives include anthracite, calcined coke, uncalcined coke, burned oil shale and raw oil shale.

Abstract: Electricity is generated during the injection of a dense fluid through an injection well and into a subterranean formation having a connate fluid pressure less than the available downhole pressure of injection fluid in the injection well. A fluid engine/generator is positioned in the well to define upper and lower zones in the well; a level of dense fluid is established in the upper zone; and dense fluid is flowed from the upper zone through the fluid engine/generator and into the subterranean formation to thereby generate electricity, which is subsequently recovered. Control of the downhole fluid pressure is also achieved.

Abstract: A method for producing mechanical energy from geothermal brine in which a heat transfer fluid (HTF) is heated by direct contact with the hot geothermal brine in cocurrent flow through a series of flash stages which are maintained at successively lower pressures so that the HTF is vaporized in each stage. A working fluid is countercurrently flowed through the series of flash stages in indirect heat exchange with the vapor produced in each stage so that the vapor is condensed in each stage and the working fluid is progressively heated as it passes through the series of flash stages. The heated working fluid is utilized in a heat engine for the production of mechanical energy.

Abstract: A method for drilling a well through a subterranean formation containing one or more zones of unconsolidated dolomite, wherein the drilling operation is interrupted periodically to consolidate the newly drilled incompetent dolomite by the injection of a sequence of reactant slugs comprised of (I) an aqueous solution containing an acid, a surface active agent and a precipitating agent for silicates, (II) an aqueous solution containing a water-soluble silicate, and (III) an aqueous solution containing a precipitating agent for silicates.

Abstract: A cement system including a carbon-containing, low volatile material additive admixed with cement in proportions sufficient to provide a fixed carbon content of at least 0.02 weight percent is used to cement high temperature wells. Additives include anthracite, calcined coke, uncalcined coke, burned oil shale and raw oil shale.

Abstract: Apparatus and method for mooring a tension leg platform at an offshore location wherein the tensioned cables of the platform legs are laterally supported by a plurality of rigid, fixed-dimensioned support members which interconnect the legs and are vertically spaced at predetermined positions along the cables to reduce the unsupported length thereof and to thereby increase the fundamental frequency of the cables to a value higher than the flutter frequencies likely to be encountered. Resonant fluttering of the cables due to vortex shedding is thereby prohibited and the useful life of the cables is extended. The support members can be variably buoyant and/or can be adapted to provide storage for fluids produced at the offshore location.

Abstract: An enhanced oil recovery process employing an aqueous alkyl polyethylene oxide sulfate solution and a carbon dioxide displacement fluid at injection pressures above about 1,500 p.s.i. The aqueous solution of an alkyl polyethylene oxide sulfate having 8 or 9 carbon atoms in the alkyl group and between 1 and 5 ethoxy groups significantly improves the areal sweep and overall efficiencies of dense fluid carbon dioxide enhanced oil recovery processes, especially under high salinity and low pH conditions. The efficiency of the process is increased as the injection pressure is increased.

Abstract: Wellhead flow control apparatus for controlling the flow of fluids from a well producing fluids and debris including a novel device for separating and accumulating the debris. The device comprises an outer shell defining an enclosed accumulation chamber, a perforated outlet conduit communicating with the chamber to allow the passage of fluids but prevent passage of debris, and access means to facilitate periodic removal of the accumulated debris. The wellhead apparatus is especially useful for flow control of fluids from geothermal steam wells.

Abstract: Carbon dioxide is admixed with water to form a carbonic acid solution for use as a leaching solution for extraction of uranium by solution mining. An oxidizing agent is also present in the solution.