Abstract: Multi-phase fluid saturation in a sample of a porous media is determined through computed tomographic scanning. The sample is scanned with X-rays of differing energies in both the fluid saturated and fluid-extracted states. Each of the extracted fluids is also scanned at differing X-ray energies. The computed tomographic images produced are utilized in the determination of the X-ray mass attenuation coefficients for the sample and the extracted fluids. From these mass attenuation coefficients, the weight fractions and volume fractions of each of the extracted fluids are determined.

Abstract: Acoustic well logging method and system employing a bender-type transducer as a point source of an acoustic shear wave. The bender-type transducer includes opposed unrestricted planar surfaces mounted within a liquid filled compartment within the tool. The unrestricted surfaces of the transducer are spaced longitudinally along the axis of the tool and exposed to the coupling liquid. One or more bender-type transducers may also be employed as acoustic receivers in the tools. The active surfaces of the receiving transducers are oriented in substantially the same direction as the active surfaces of the transmitting transducer.

Abstract: A rotary well drilling system employs a drill pipe with a drill bit affixed at its lower end for the drilling of a wellbore. Drilling fluid is circulated through the drill pipe to remove drill cuttings. When raising and lowering the drill pipe in the wellbore, the drill pipe is continuously rotated along with continued drilling fluid circulation to prevent sticking of the drill pipe. The drill bit is rotated by a mud motor in the opposite direction from that of the drill pipe and at the same speed so that the drill bit remains rotationally stationary with respect to the wellbore and does not side-track as it is dragged along the lower side of the wellbore wall when being raised or lowered in an inclined wellbore.

Abstract: A rotary well drilling system employs a drill pipe with a drill bit affixed at its lower end for the drilling of a deviated wellbore. Drilling fluid is circulated through the drill pipe to remove drill cuttings. The drill bit is rotated in the opposite direction from that of the drill pipe to reduce the torque required to rotate the drill pipe as it is rotationally dragged along the lower side of the wellbore walls during the drilling of the deviated wellbore.

Abstract: A method for monitoring the movement of injected gas in an oil bearing formation behind the well casing is disclosed. A compensation neutron log is obtained from the well. The count rates are normalized to delineate water zones, gas zones and shale zones. Near and far count rates are rescaled and used to provide a qualitative determination of the distance from the point of injection to the top of the displaced gas in the formation by an analysis of the separation of the near and far count rate curves.

Abstract: Hydrocarbons are recovered from a fractured or stratified subsurface formation by means of at least one injection well and at least one production well. A first flooding agent having a high viscosity is injected into the formation to form a filtercake on the walls of the fractures or permeable streaks of the formation only in the near vicinity of the injection well. A second flooding agent having an inorganic thickener is injected deep into the formation to completely fill the thief zones provided by the fractures or permeable streaks of the formation between the injection and production wells. A first flushing agent is then injected to clear the fractures or permeable streaks of the formation only in the near vicinity of the injection well of the inorganic thickener. A second flushing agent having a breaker material is injected to remove the filtercake from the walls of the fractures or permeable streaks of the formation only in the near vicinity of the injection well.

Abstract: Vertical shear acoustic energy anisotropy of a subterranean formation is measured from a core sample of such formation. The core sample is shaped by having its outer surface cut to provide a pair of flat or planar surfaces along parallel spaced-apart planes. A pair of planar shear transducers are placed in contact with the pair of planar outer surfaces, one of the transducers being a transmitting transducer and the other being a receiving transducer. Shear acoustic energy is transmitted through the core sample in a basically elliptical pattern having an azimuthal direction within a plane parallel to the planar outer surfaces of the core sample. Any differences in travel time, attenuation, waveform or other acoustic properties for the acoustic energy transmissions in a plurality of differing azimuthal directions are a measure of the shear acoustic energy anisotropy of the subsurface formation.

Abstract: Acoustic energy anisotropy is measured in a core sample from a subterranean formation. The core sample is shaped by having its outer surface cut to provide a plurality of pairs of parallel, planar outer surfaces about the length of the core sample. A pair of planar transducers are successively placed in contact with each of the pairs of parallel, planar outer surfaces, one of the transducers being a transmitting transducer and the other being a receiving transducer. Compressional or shear acoustic energy is transmitted through the core sample in the aximuthal directions that are perpendicular to each of the pairs of parallel, planar outer surfaces of the core sample. Any differences in travel time, attenuation, waveform or other acoustic properties for the acoustic energy transmissions in the plurality of differing azimuthal directions are a measure of the compressional or shear acoustic energy anisotropy of the subsurface formation.

Abstract: A plurality of production wells penetrate an oil-bearing reservoir in a dipping subterranean formation. Steam injection wells are located up-dip and down-dip of each oil-bearing reservoir. Some time after steam breakthrough in the upper-most one of the production wells, this well is converted to a steam injection well, and the original up-dip steam injection well is shut in. Some time after steam breakthrough in the lower-most one of the production wells, this well is converted to a steam injection well, and the original down-dip steam injection well is shut-in. Some time after steam breakthrough occurs at the remaining up-dip and down-dip production wells, these wells are sequentially converted to steam injection wells, and the preceding up-dip and down-dip steam injection wells are shut in.

Abstract: A borehole gravimetry survey is carried out by making gravity measurements at a plurality of measurement stations along an interval of the borehole. A moving average gradient is determined for gravity measurements taken from consecutive pairs of such measurement stations over the borehole interval. Each moving average gradient is inverse filtered to reduce the effect of the weighted averaging on the gravity measurements, thereby increasing the vertical resolution of the data.

Abstract: A continuous gravimetry survey is carried out with a gravity logging tool having a column of fluid within the tool. First and second pressure sensors are located at spaced-apart axial positions within an upper portion of the fluid column. Third and fourth pressure sensors are located at spaced-apart axial positions within a lower portion of the fluid column. The outputs from the first and second pressure sensors are differenced to produce a first pressure difference signal. The outputs of the third and fourth pressure sensors are also differenced to produce a second pressure difference signal. The difference between these first and second pressure difference signals is related to the gravity gradient along the earth formation adjacent the fluid column. Such a gravity gradient is a continuously moving gradient that is insensitive to acceleration effects from unsteady motions of the logging tool as it traverses the earth formation during the gravimetry survey.

Abstract: A microwave electromagnetic logging tool for use in the determination of the dip of subsurface earth formations includes a continuous source of microwave energy, three microwave antennas positioned from the longitudinal axis of the logging tool and spaced approximately equally around such axis, and a device for measuring the loading effect on the three antennas as the three antennas continuously transmit microwave energy into the formations during movement of the logging tool through the borehole.

Abstract: A thermal oil recovery process in which steam is injected into a heavy oil-bearing formation through a horizontally-drilled injection well and oil is produced through a horizontal production well parallel to the injection well.

Abstract: A fiber optic bulkhead penetrator for allowing fiber optic communication lines to penetrate through an undersea bulkhead employed in offshore oil well exploration and production apparatus having a very high pressure differential thereacross. The arrangement consists of a port and cofferdam installed in the undersea oil well exploration and production apparatus, and a bullnose penetrator, having a plurality of bulkheads therein, terminating an undersea fiber optic cable used for data transmission. The bullnose penetrator serves as a mating plug for a port provided in the oil well apparatus, with three sets of seals isolating the single-atmosphere environment from the ambient seawater pressure. A shoulder is provided on the penetrator and in the port to hold the penetrator in place once the cofferdam is evacuated and lowered to habitat pressure.

Abstract: A borehole gravimetry system employs a pair of pressure transducers for lowering into a borehole along with a borehole gravity meter. The pressure transducers are spaced apart vertically within a pressure sonde for producing a pressure differential measurement of the wellbore fluid. A first of the transducers is hydraulically isolated from borehole fluid pressure while the second of the transducers is in hydraulic contact with the borehole fluid so as to be exposed to the borehole fluid pressure. The second transducer is thermally insulated from borehole temperature to achieve thermal time constant equalization between the pair of transducers. A pressure differential measurement and a gravity reading is taken for each of a plurality of vertical locations within the borehole as the borehole gravimetry system is advanced through the borehole and from these measurements bulk density is determined.

Abstract: A logging sonde injects alternating current into the well casings of a plurality of producing wells at desired subsurface depth points. The resulting magnetic fields created around the well casings of the producing wells are detected by a magnetometer in a new well being drilled to prevent drilling into one of the production wells.

Abstract: A method of measuring hardness in steel casing to detect soft spots. A magnetizing force is generated and traversed along the length of the steel casing. A flux density is created along those portions of the steel casing traversed by the magnetizing force. The flux density is monitored to detect any change in such flux density caused by the presence of a soft spot in the hardness of the steel casing.

Abstract: The foaming characteristics of a foamant to be used in the recovery of oil from a subterranean oil-bearing formation by carbon dioxide foam flooding, are determined by passing carbon dioxide through a sample of the foamant in a test cell containing a porous medium under pressure conditions simulating reservoir conditions and measuring the quantity of foam formed. The pressure drop along the cell is also monitored in order to indicate the resistance to gas flow imposed by the foam.

Abstract: A borehole logging tool includes a pulsed source of fast neutrons and a neutron sensitive counter. A neutron filter encases the counter and has a thickness to permit the longest possible delay time following each burst of fast neutrons before epithermal neutrons from the irradiated formation are detected by the neutron counter while at the same time minimizing thermal neutron effects.

Abstract: An aerial natural gamma radiation survey is conducted over an exploration region. A change in the measured T1-208/K-40 ratio in the exploration region in contrast to a region known not to be hydrothermally altered identifies the exploration region as a hydrothermal alteration. A surface natural gamma radiation survey is conducted over the hydrothermally altered exploration region. A change in the T1-208/K-40 ratio at specific sites within the exploration region indicates the location of alteration products.