Abstract: Fractures are initiated or extended within an earth formation from a well which includes a tubing string extending to a wellbore space adjacent the fracture zone from a conventional wellhead. Carbon dioxide, nitrogen or a similar highly expansible fluid is pumped into the wellbore space and/or at least a portion of the tubing string at a pressure greater than the fluid critical pressure and greater than the fracture initiation or extension pressure required in the formation zone. A perforating gun is fired or a shear disk is actuated to release the expansible fluid to flow into the formation at an initial velocity and kinetic energy which substantially exceeds that which is obtained with water or similar conventional fracturing fluids so as to initiate or extend hydraulic fractures with a minimum radius of curvature with respect to the wellbore.

Abstract: A surface mining system for mining successive, generally parallel cuts in a coal or similar mineral seam includes at least one endless belt conveyor disposed on a spoil pile directly adjacent the cut being excavated and a second conveyor extending from the first conveyor to a material storage site. Material is transferred to the first conveyor by an excavator working the longitudinal extent of the cut and transferring excavated material to a moveable crusher and conveyor apparatus which transfers the material to a second moveable crusher and conveyor apparatus. The second moveable crusher and conveyor apparatus discharges material onto the conveyor disposed on the spoil pile. The mineral seam may be mined by progressively advancing into the seam with successive parallel cuts and progressively moving the conveyor system onto newly formed portions of the spoil pile.

Abstract: Hydraulic fractures which extend between a hydrocarbon fluid producing zone of an earth formation and a water-producing zone are sealed with respect to the water-producing zone by simultaneously injecting a non-sealing fluid such as crude oil, diesel fuel or brine into the portion of the fracture extending within the hydrocarbon producing zone and injecting a settable gel composition such as a polyacrylamide polymer cross-linked with inorganic transition metals into the portion of the fracture extending within the water-producing zone. The flow rates of the simultaneously pumped fluids are controlled in accordance with the ratio of the respective fracture heights and the viscosity and density of the respective sealing and non-sealing fluids. One fluid is typically pumped through the well annulus while the other fluid is pumped through a tubing string which is sealed from the annulus by a conventional packer disposed at the interface between the hydrocarbon and water-bearing zones.

Abstract: Petroleum coking drums and other vessels may be inspected to determine if dimensional changes or bulges have occurred in the surface of the vessel by an inspection device including a reflected laser light measuring survey apparatus and a video camera mounted on a frame which may be disposed in selected vertical positions along a central axis of the vessel and rotatably positioned by a rotary positioner interposed between a support stem for the device and the frame. Plural distance measurements and video scans are transmitted to a remote control console for recording and plotting of the contours of bulges or other dimensional anomalies surveyed by the survey apparatus. Components of the device are sealed or gas pressurized to minimize the chance of explosion in hazardous environments such as the interior of a petroleum coking drum. The system is adapted to be supported on the distal end of a coking drum drillstem and centralized by a removable clamp unit mounted on the drum manway flange.

Abstract: Natural gas is reinjected into an earth formation for storage and/or stimulating the recovery of hydrocarbon liquids by mixing the gas with water at a pressure sufficient to maintain bubble flow of gas dispersed in a water flowstream in a range of volumetric gas fraction up to about twenty percent of total flow. A water and gas distribution system includes static flow mixers for maintaining uniform distribution of gas bubbles in the water flow stream through the distribution conduits. The mixers may comprise multi-stage bladed mixing elements of the same or opposite pitch and extending across the intersection of branch conduits with the main conduit of the distribution system. The water and gas may be mixed in an injection well having a tubing string extending within the well and having a distal end below the point of injection into an earth formation so that a uniform gas and water mixture enters the formation through the well perforations.

Abstract: A process for removing calcium from an amine-water solution is provided by using a low calcium cationic exchange resin which preferably has large pores to avoid hydrocarbon coating of the resin. Preferably, the resin is pretreated to reduce calcium concentration of the resin to less than two parts per million prior to use for calcium removal.

Abstract: Fluid production or injection wells may be used to transmit or receive seismic signals by lowering a signal transmitting device within a tubing string disposed in the well and exerting a pressure fluid force on a free bottom end of the tubing string to cause the tubing string to helically deflect within the well and engage the wellbore wall firmly over a large portion of the tubing string to enhance the quality and intensity of the signal transmitted between the transmitting device and the earth formation penetrated by the well.

Abstract: Coal and other mineral seams are uncovered of overburden to a predetermined width by blast casting a portion of the overburden into an adjacent spoil pit followed by fragmentation blasting of the remaining width of the overburden panel. A dragline excavator is moved at least partially onto the fragmented overburden for excavating a keycut portion together with excavation to level the bench for an adjacent overburden panel and placement of the material on a temporary spoil pile.

Abstract: Subterranean mineral seams, such as coal, which have been penetrated by gas production wells are stimulated to produce additional gas by placing a liquid, such as a solvent for coal, in the wellbore and in communication with a tubing extending within the wellbore and having a frangible shear disk assembly disposed therein. Pressure is increased inside the tubing string by pumping gas and/or liquid into the tubing string in sufficient quantity to cause the shear disk to release fluid pressure to act on the fluid in the open hole wellbore portion so that a substantial pressure pulse is exerted on the coal seam to effect rubblization of the coal to form a cavity and release entrapped or adsorbed gas for production up through the well. Imposition of rapid and cyclic pressure pulses on the coal seam at pressures up to 5000 psi above the in situ stress improves production of gas therefrom.

Abstract: An auger type gravel pack screen assembly is interposed in a well which is adapted to produce fluids from two spaced-apart zones of interest through gravel packing surrounding the screen assembly. The screen assembly includes a blank pipe section extending through a layer of mixed size gravel of relatively low permeability to prevent the flow of water or gas through the wellbore between the producing zones. The mixed size gravel layer may be placed in the well with a dump type bailer to minimize mixing of the mixed size gravel with a layer of gravel already in the well. The intermediate layer of gravel packing may have its permeability reduced by injecting a settable resin material or the like through a section of the screen assembly which is adapted to provide for injection of such permeability reducing material from a tubing string inserted within the well.

Abstract: Injection well fluid flow is measured by a device which has a running head and a body with a turbine type flowmeter interposed therein between the running head and discharge port means in the body. The running head may be interchangeable for positioning the body in selected positions in a tubing string in sealing engagement with a seating surface in the tubing string whereby fluid flow entering selected zones in communication with the injection well may be directly measured. The flow measuring device may include a signal storage or memory circuit disposed thereon for receiving and storing signals from the flowmeter.

Abstract: A method for converting methane to higher hydrocarbon products and coproduct water wherein a gas comprising methane and a gaseous oxidant are contacted with a nonacidic catalyst at temperatures within the range of about 700.degree. to 1200.degree. C. A preferred catalyst comprises an alkali component associated with a support material. Results obtained over alkali-promoted solids are enhanced when the contacting is conducted in the presence of halogen promoters.

Abstract: Hydrocarbon bearing earth formations are treated to reduce formation permeability and fill void spaces by injecting a polymer gel solution having an artificial matrix material dispersed therein and comprising beads of materials such as polystyrene and polycarbonate having densities substantially the same as the density of the polymer gel to improve distribution of the artificial matrix material into such void spaces.

Abstract: Liquid wastes and slurries of ground solids wastes are injected into earth formation zones which have a fluid content of fluid similar to the liquid wastes or slurry which is below the irreducible saturation level for the liquid wastes or slurry to be injected. The formation may be non-hydrocarbon bearing or a depleted hydrocarbon bearing reservoir which has been depleted by enhanced fluid recovery techniques below its ambient irreducible fluid saturation value.

Abstract: In a method of logging a well in a subterranean formation which formation has been fractured by injecting proppant tagged with at least one radioactive material into the formation through the well, the improvement comprising: utilizing a spectral gamma-ray tool in performing the logging. By analyzing one or more selected ratios of counting rates at certain energy areas of the spectrum one can determine the vertical height of the fracturing in the formation.

Abstract: Lateral vibrations of drillstring bottom hole assemblies are confirmed by sensing longitudinal and torsional accelerations or displacements of the drillstring at or near its top end during rotation and determining the lateral critical speed and displacement of the drillstring from the mode shape of the bottom hole assembly which occurs during forward synchronous whirl and longitudinal shortening of the bottom hole assembly resulting from such whirl. Lateral motion of the bottom hole assembly, while drilling, is estimated based on longitudinal and torsional measurements at the top of the drillstring. Radial displacement of the bottom hole assembly due to impacting of the borehole wall imparts a torsional impulse which, together with considerable radial motion, is repeated each revolution. The lateral or radial motion causes a small axial motion to develop in the bottom hole assembly which results in an axial force on and axial shortening of the drillstring which varies once per revolution.

Abstract: Methods are provided for overpressured perforating and fracturing of a subsurface formation in a substantially deviated well. A perforating gun is run into the well and is pushed through the deviated portion thereof on a coiled tubing string. The coiled tubing string contains an internal supporting pressure which is high enough to prevent collapse of the coiled tubing string prior to perforation of the well and which is low enough to avoid rupturing the coiled tubing string. After the perforations are formed and the fractures are initiated, the supporting gas pressure in the coiled tubing string is bled off to the atmosphere and the coiled tubing string and perforating gun are retrieved.

Abstract: Multiphase fluid flow, such as a mixture of oil, water and gas, is measured by a system which includes one or two densitometers for measuring the multiphase fluid density flowing through a flowline or conduit and a flow restriction, pump, expander or heat exchanger interposed in the flowline between the densitometers to effect a pressure or temperature change in the multiphase fluid. Densities, pressures and temperatures are measured on the upstream and/or downstream sides of the flow restriction, pump, expander or heat exchanger and the measured values of density, pressure and temperature are used to obtain the flow rates of the respective phases in the flowstream.

Abstract: A gravel pack well tool comprised of a workstring having a gravel pack screen thereon wherein the workstring can be rotated without applying any substantial torque to the screen jacket which forms part of the gravel pack screen. This allows the workstring to be rotated in either direction during installation or removal of the gravel pack screen without damaging the screen jacket. The gravel pack screen is comprised of a fluid-permeable base pipe having a screen jacket rotatably mounted thereon.