Abstract: A method for time lapse electric logging in a cased hole in which electrodes are implanted in the casing or the hole is completed with a gravel packed non conductive, perforated liner that allows an open hole logging tool to be used for time-lapse logging. Thereafter, the implemented electrodes or a self-potential (SP) logging tool are used to monitor a steam-flooding EOR method by detecting two-phase flow with time lapse logging. A potential drop between the surface and zones of interest is measured with electrodes installed in a non-conductive casing or the SP logging tool.

Abstract: A method for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous silicate solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent containing an alkylpolysilicate is injected into the interval. A permeability retaining silica cement is formed in the interval thereby making a gravel pack. Injection of the aqueous silicate and organic solvent containing an alkylpolysilicate is continued until the interval has been consolidated by the silica cement to an extent sufficient to exclude sand and formation fines.

Abstract: A sand consolidating method is provided for use in a borehole within an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole and cause caving. After perforating the borehole's casing at an interval of the formation where sand will be produced, an aqueous silicate solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent containing an alkylpolysilicate and inorganic salt or chelated calcium is injected into the interval. A permeability retentive silicate cement is formed in the interval. Injection of the aqueous silicate and organic solvent is continued until the interval has been consolidated by the silicate cement to an extent sufficient to prevent sand migration and thereby prevent caving.

Abstract: A method for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. Initially, an aqueous solution of an alkali metal hydroxide, ammonium hydroxide or organoammonium hydroxide is injected into a zone of greater permeability in a formation. Thereafter, a spacer volume of a water miscible organic solvent is injected into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the greater permeability zone. A silica cement is formed in-situ thereby substantially closing off the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide stimulation or fire-flooding EOR operation is commenced in a lower permeability zone.

Abstract: A method for forming a consolidated gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous hydroxide solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid slug is injected into the interval. Thereafter, a water-miscible organic solvent slug containing alkylpolysilicate is injected into the interval. A permeability retentive silica cement is formed in the interval thereby making a consolidated gravel pack. Injection of the aqueous hydroxide and alkylpolysilicate slugs is continued until silica cement has been deposited to an extent sufficient to exclude formation fines and sand.

Abstract: A method and composition for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. An aqueous solution of an organoammonium silicate, alkali metal or ammonium silicate is injected into a zone of higher permeability in a formation. Subsequently, a spacer volume of a water-immiscible organic solvent is directed into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the higher permeability zone. A silica cement is formed in-situ thereby substantially closing the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide-flooding, or fire-flooding EOR operation is commenced in a lower permeability zone.

Abstract: A method for producing substantially sand or fines free hydrocarbonaceous fluids from a wellbore which is initially gravel packed. Thereafter, an acid is directed into the wellbore so as to dissolve formation fines in channels contained in perforations communicating with a productive interval of the formation. The acid is of a strength sufficient to dissolve said fines. After the fines are dissolved, a sand consolidation agent is introduced into the perforations before the channels can be filled with formation fines. The consolidation agent remains in the perforations for a time sufficient to form a cement in situ which cement has permeability retentive characteristics. The cement forms pores of a size sufficient to exclude formation fines from the wellbore.

Abstract: A foam/steam injection method for forming fractures is a for reservoir penetrated by a horizontal wellbore. Steam is injected into said wellbore at a pressure sufficient to fracture the formation. Water which is used to make the steam contains a foamable composition in an amount sufficient to make a foam upon contact with steam. Steam and foam enter the wellbore and create a fracture in an oil-rich zone. Thereafter, foam blocks further steam entry into the created fracture which causes another fracture to form at a second interval along the horizontal wellbore. These steps are repeated until a fracture system is made along the length of the wellbore.

Abstract: This invention is directed to a method to improve matrix acidizing of a carbonate containing formation by taking advantage of wormholes which are created during acidizing. The wormholes are closed with a solidifiable gel which protects them from entry of additional acid. The solidifiable gel is allowed sufficient time to form a solid. After a solid gel is formed, additional acid is directed into the formation where it moves past the wormholes containing the solid gel. Thereafter, an additional volume of solidifiable gel is directed into the formation where it protects any subsequently formed wormholes and diverts the acid further into the formation. An additional volume of acid is directed into the formation and the steps repeated until the formation has been acidized to obtain a desired degree of permeability.

Abstract: An accelerator-type neutron source employs a target, an ionization section and a replenisher for supplying accelerator gas. A positive voltage pulse is applied to the ionization section to produce a burst of neutrons. A negative voltage pulse is applied to the ionization section upon the termination of the positive voltage pulse to effect a sharp cut-off to the burst of neutrons.

Abstract: A method of logging a subsurface formation surrounding a borehole includes the recording of an induced polarization log, the recording of a nuclear log of delayed gamma rays from the activation of aluminum in the formation, and the recording of a nuclear log of inelastic scattering gamma rays from the activation of iron in the formation. The induced polarization log and the nuclear logs are combined to identify the composition of the lithology of the subsurface formation.

Abstract: A rotary transfer subsystem is described for transferring production fluids, electrical power, hydraulic power, and control signals across a rotating interface between an offshore process vessel and a flowline bundle of service hoses and high-pressure hoses which are connected to a deepwater production riser system. Tensioning devices are also described for maintaining a selected tension on terminal hoses between the interface and the vessel while the vessel weathervanes during maintenance of position in a watch circle above the riser system. The subsystem and the tensioning devices are mounted on the vessel which is equipped with a powered turret within a circular moonpool and is capable of performing most subsea service functions on the riser system without major equipment support.

Abstract: A method and system for monitoring the ore grade of an uranium bearing fluid mixture. A sample of the fluid mixture is irradiated with neutrons. Delayed fission neutrons resulting from the fission of uranium present in the sample are counted as an indication of uranium ore grade.

Abstract: Circumferential and longitudinal strain measurements are carried out on a rock material under oscillatory loading conditions at seismic frequencies. The phase angle between each of these strains and the oscillatory driving force is determined by synchronous and quadrature detection.

Abstract: In the production or stimulation of a well, the length change of a string of tubing caused by temperature and pressure is determined for an inclined well. The weight of each section of the tubing is resolved into the axial component applied to the next successive section. For each of the successive sections the buckling force is determined from the actual force and the axial component of weight. This buckling force is compared to a threshold to determine if buckling occurs. The length change of the tubing between the initial condition and the condition of fluid flow in the tubing caused by the pressure and temperature of the fluid and caused by buckling if it is present is determined. An output indicates the change in length of the tubing and the stress applied to the tubing.

Abstract: A radioactive medium simulates a desired subsurface formation condition for the testing and calibration of radioactive well logging tools. The medium simulates a state of radioactive equilibrium in which the decay products of the parent isotope decay at a desired rate to that at which they are produced within the medium.

Abstract: A borehole logging tool includes a steady-state source of fast neutrons, two thermal neutron detectors, and two gamma ray detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. A second ratio detector provides the ratio of the outputs of the two count rate meters connected to the two gamma ray detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and porosity can be determined.

Abstract: A method of magnetotelluric exploration is disclosed which features multiple measurements of the earth's electric field at a plurality of locations and one or more magnetic field measurements being made simultaneously. A specific form of cable for connecting measurement apparatus with recording apparatus is also disclosed.

Abstract: A neutron accelerator tube having a target section, an ionization section, and a replenisher section for supplying accelerator gas to the ionization section. The ionization section is located between the target and the replenisher section and includes an ionization chamber adapted to receive accelerator gas from the replenisher section. The ionization section further includes spaced cathodes having opposed active surfaces exposed to the interior of the ionization chamber. The active surface of at least one of the cathodes is formulated of a .beta..sup.- emitting material. An anode is located intermediate the cathodes whereby in response to an applied positive voltage, electrons are transmitted between the opposed active surfaces of the cathodes and produce the emission of secondary electrons. The active surface of the other cathode may be formulated of a .beta..sup.- ray emitter or of material having a secondary electron emission factor of at least 2.

Abstract: A borehole logging tool includes a source of fast neutrons and a fast neutron detector. A discriminator connected to the detector rejects pulses from the detector attributable to nonsource neutrons from the formation and passes to a count rate meter those pulses from the detector attributable to source neutrons. The output of the count rate meter is recorded as a measure of neutron source output.