Abstract: Liquid slug flow in oil production well flowlines and the like is controlled by a throttling valve in the flowline upstream of a gas-liquid separator and a differential pressure gauge, densitometer or other device for measuring the presence and the volume of the slug in the flowline. The throttling valve may be actuated to throttle fluid flow into the separator in relation to the presence of the slug and the duration of the slug as determined by the slug detection device. Slug mitigation may also be controlled by throttling flow into the separator in relation to the level of liquid in the separator between a threshold level and a maximum liquid level. A third method for mitigating slug flow measures the available volume in the separator vessel and the volume of the liquid slug moving toward the separator vessel to effect proportional throttling of fluid flow. A liquid slug may be detected by a differential pressure gauge or a densitometer interposed in the flowline upstream of the throttling valve.
October 20, 1993
Date of Patent:
August 13, 1996
Atlantic Richfield Company
Richard L. Payne, Richard E. Huff, Wayne E. Ogren
Abstract: Multiphase fluid flowstreams of gas, oil and water are measured by flowmeters which include an embodiment using a turbine flowmeter and a densitometer with total accuracy in the range of .+-.15%, and an embodiment using a gas-liquid separator and a Coriolis flowmeter for flowstreams of a relatively high gas-to-liquid ratio with accuracies of .+-.5% when the gas carry-over in the liquid flowstream is less than about 5%. A second alternate embodiment includes a water fraction meter, a turbine flowmeter and a densitometer for measuring flows with relatively low gas-to-liquid ratios but accurate measure of the water fraction. A meter capable of handling relatively high gas-to-liquid ratio but with residual gas in the liquid flowstream of less than 5% includes a separator, a Coriolis meter for measuring the liquid density and mass flow rate in the liquid flowstream and a densitometer and turbine flowmeter for measuring the fluid in the gas flowstream leaving the separator.
Abstract: Slurried solids waste materials are disposed of into a preselected subterranean disposal zone by generating radially extending hydraulic fractures from a disposal well and filling the primary fractures with disposal material until screenout is observed or it is determined that the fracture is filled with waste material from monitoring fracture growth and measuring the injected volume of material. The fluid flow rate is allowed to decline to provide relaxation and closure of the fracture at a point between the fracture tip and the injection well and secondary fractures are then created by injecting a fracturing fluid followed by further injection of waste material to fill the secondary fractures. The process is repeated to establish a dendritic array of multiple hydraulic fractures in the disposal zone sufficient to hold a predetermined quantity of waste material.
Abstract: Corrosion in well tubing strings, pipe and similar conduits may be determined by a circuit which includes a current sensitive meter and a known voltage source which is placed at selected intervals in the tubing string to make current flow measurements and voltage drop measurements between spaced apart contactors engaged with the tubing string at the selected intervals. The current flow measurements from the known source are used to determine resistance of the measured interval and voltage drop from a second source imposed on the tubing string at the surface is measured at the selected intervals to determine current flow from the second source. The differences in current flow at the selected intervals at a first measurement are compared with the differences in current flow at the same intervals at a later time to indicate any changes in current flow which may be related to corrosion in the tubing string between the intervals of measurement.
January 10, 1995
Date of Patent:
July 9, 1996
Atlantic Richfield Company
Jerry L. Brady, Stephen Gerlek, David L. Lagerlef, Raymond Wydrinski
Abstract: Oil-separation and recovery from marine oil spills is carried out by a system which includes a containment boom, a weir and/or foil type skimmer, a separator unit and a second, fire proof containment boom for receiving separated oil in a closed containment area on the surface of the body of water from which the oil has been recovered and wherein the oil may be combusted. The separator unit uses so-called superabsorbent materials including sheets of non-woven fibers or flakes of materials including sodium carboxymethyl cellulose, acrylonitrile grafted starch absorbents, polyacrylates, copolymers of styrene and maleic anhydride and copolymers of unsaturated monomers and recurring units of at least one copolymerizable comonomer comprising about 20% to about 80% pendant carboxylic acid units and about 80% to about 20% pendant carboxylate salt units blended with a monomer containing at least two hydroxyl groups.
Abstract: Remotely controllable fluid flow control valves are disposed in the main wellbore and branch wellbores of a multiple well. Each flow control valve has a radio frequency range receiver, a controller and an actuator for moving a closure member to a selected position to control fluid flow in the wellbore in which the valve is disposed. A signal transmitter may be conveyed into the main wellbore by an E-line or coilable tubing and radio frequency range electromagnetic wave energy signals may be transmitted to the selected valve to effect fluid flow control within each wellbore of the multiple well. The remotely controllable valves eliminate expensive and difficult procedures associated with reentering branch wells extending from a central or main wellbore.
Abstract: A method of reducing fluid loss into a highly conductive formation interval during drilling and completion of a well through such an interval wherein a foamed cement slurry, including an acid or oil soluble component, is injected into the well and forced into the conductive portions of the formation zone, which may comprise a fractured or rubblized formation portion. The cement is allowed to harden or set at a porosity of at least 15%, followed by resuming drilling and, in completing the well, dissolving the soluble component to increase the permeability of or disintegrate the cement to permit production of formation fluids into the well.
Abstract: Multiphase fluid flowstreams may be analyzed to determine to gas fraction of the fluid by defining a zone in a conduit in which the fluid flowstream is caused to vibrate either laterally or longitudinally at a resonant frequency of vibration of the fluid flowstream using a transducer or by causing the fluid to flow through an orifice in the conduit. A vibrating zone within the conduit is delimited by spaced apart ports in the conduit and/or spaced apart grilles which reflect the longitudinal vibrations. Lateral vibrations may be enhanced by causing the flowstream to flow through a rectangular passage in the conduit. Spectral analysis of the vibrating flowstream identifies the resonant frequency of vibration which, together with pressure and temperature measurements may be used in calculating the gas fraction.
Abstract: Pressure and temperature signals are transmitted between a predetermined point in a wellbore and the earth's surface by an electromagnetic wave transmitter disposed in the well and connected to a bow-spring centralizer forming one contactor of a dipole and a mandrel or hanger connected to a landing nipple of a tubing string in the well whereby the other conductive path forming the other end of the dipole may be formed by a packer or similar mechanism in conductive engagement with the tubing string and the well casing. The hanger may be a lock mandrel or a suitable conventional downhole tool hanger. The electromagnetic wave transmitter may be deployed in the well and engaged with the casing by spaced-apart magnets to establish the conductive path and the dipole distance.
Abstract: Organic waste such as hydrocarbon waste, refinery sludges, tank bottom sludges, certain wastes from paint, solvent and wax manufacturing and active metals and active metal oxide compositions are disposed of by combining such compositions with bentonite and water to adsorb the waste composition into the bentonite followed by injection of the waste, bentonite and water slurry into a subterranean disposal zone to fix the waste material within disaggregated matrix or created fractures.
Abstract: Deviated wells, in particular, are hydraulically fractured at reduced rates and with higher viscosity fracturing fluids if the fracture design indicates during an initial test fracture that the instantaneous shut-in pressure, upon cessation of injection, exceeds a predetermined amount indicating high friction pressure losses in the near wellbore region of the fracture. Increasing the fracture fluid viscosity and reducing the fracture fluid rate of injection minimizes the creation of multiple fractures of reduced width in the near wellbore region and the high probability of fracture screenout resulting from the creation of the multiple reduced width fractures.
Abstract: Toxic wastes including naturally occurring radioactive materials are disposed of into subterranean earth formation zones which are bounded both above and below by zones which have higher in situ compressive stresses. The materials are prepared in a slurry of finely ground solids and a carrier liquid and are injected into a fracture created in the disposal zone by a process which includes initiating and extending the fracture with a fracturing fluid having a filter cake building solids material entrained therein to build a sealant layer on the fracture faces, The fracture fluid is followed by injection of the waste material which is followed by injection of more fracture fluid and/or a clear liquid such as fresh water or seawater to remove all toxic material from the injection well and the vicinity thereof. The fracture is then allowed to close to confine the waste material therein.
Abstract: A gas-liquid separator for a well pump includes a stationary helical baffle disposed in a tubular housing for separating gas from liquid and conducting gas through a center conduit disposed in the housing to a tubing string in communication with the separator or into the well annulus for flow to the surface. The baffle may be interposed in a conventional downhole submersible pump between the motor section and the pump section and the pump section may be modified to have a hollow impeller drive shaft for conducting gas separated by the separator through the pump section and out of gas discharge ports in the pump section housing. In an alternate embodiment gas is discharged from the hollow drive shaft into the tubing string and liquid separated from the gas is pumped through the pump section and out into the wellbore annulus.
Abstract: Earth formation evaluation for detection of hydrocarbon fluids is carried out by a microwave frequency range sensor (antenna or wave guide) disposed in the face of a diamond or PDC drill bit configured to minimize invasion of drilling fluid into the formation ahead of the bit. The sensor is connected to an instrument disposed in a sub interposed in the drill stem for generating and measuring the alteration of microwave energy. In particular, the dielectric constant of the earth formation in a zone which is substantially uninvaded by drilling fluid may be detected and compared with density and/or porosity logs to determine the presence of hydrocarbons in relatively thin layers of formation material.
Abstract: A pipe and tube cleaning system, particularly useful for cleaning scale from pipes and tubes used in oil and gas production operations and containing naturally occurring radioactive materials in the scale, includes an elongated closable tub for supporting a section of pipe or tube for combined hydraulic jet blast and mechanical cutting and cleaning action by a lance insertable within the pipe to remove scale from the interior of the pipe. A slurry of particulate material removed from the pipe and the cleaning liquid (water) is collected in the tub and discharged to a particle size reduction and filtering system which reduces the particle size of the material to form a slurry of very fine particles which may be disposed of through an injection well. Some of the slurry may be returned to the system for use as cleaning liquid. Pipe is loaded into and removed from the tub by a pipe handling mechanism including retractable supports with ramp surfaces which position the pipe for movement into and out of the tub.
November 10, 1993
Date of Patent:
December 12, 1995
Atlantic Richfield Company, The Standard Oil Company
David J. Lowe, Alan McArthur, Mark A. Major
Abstract: A wellbore is formed in the earth with an elongated, non-rotating tubular drillstem which may consist of a well casing or liner and including an expendable sub and reamer bit part connected to the lower distal end of the drillstem. A retrievable drilling fluid operated motor and drive member assembly are disposed in the drillstem. The motor and drive member include pressure fluid responsive mechanism for engagement with and disengagement from the reamer bit part to rotatably drive the reamer bit part and a central bit part connected to the drive member without rotating the casing type drillstem. The motor, drive member and central bit part may be retracted from the drillstem upon completion of drilling operations without retrieving the expendable reamer bit part.
Abstract: A land vehicle system for collecting crude oil and other contaminants which have been spilled on snow and ice covered surfaces includes a crawler tractor having an auger type collection and transfer mechanism mounted forwardly thereof for skimming the contaminant and a layer of snow and/or ice from the Earth's surface. The recovered oil and snow and/or ice are transported by a vacuum line to a storage and transport vehicle towed by the tractor. The storage and transport vehicle may be self-propelled and includes an onboard storage tank which is heated to melt the snow and/or ice and a separator for separating air used to transport the contaminated snow and/or ice to the tank. The tractor includes onboard prime movers for operating a vacuum pump for collecting the contaminated snow and/or ice and a prime mover for propulsion and operation of the skimming and collection mechanism.
Abstract: A survey system including a survey instrument operable to receive signals indicating the Easting, Northing and elevation of a surveyed point. The survey instrument transmits data regarding the surveyed point coordinates to a radio terminal mounted on the survey instrument and having a command keyboard associated therewith. The radio terminal is operable to communicate with a base radio and controller connected to a digital computer which stores survey data for a predetermined number of survey points and is capable of performing calculations of at least elevations of points disposed intermediate a set of coordinates on a survey grid and calculating hole depth for blastholes based on the elevation of a surveyed point on the surface of material from which the hole is to be drilled. The base radio and controller are operable to communicate with plural survey instrument and radio terminal units.
Abstract: Predetermined quantities of slurried solids wastes are injected into earth formation waste disposal zones having a predetermined in situ stress distribution and compaction rate for a predetermined hydraulic injection pressure and wherein the disposal zones are bounded by zones having greater in situ stresses. Unconsolidated or lightly cemented formation zones may be used for waste disposal wherein it is determined that a substantial compaction of the material defining opposed faces of hydraulic fractures may occur. Fracture volume available for retention of solids in the slurry is calculated based on fracture height, fracture length, elastic deflection of the fracture faces, compaction of the fracture faces and the number of fractures based on either unequal or substantially equal horizontal stress distributions.
Abstract: Mine tailings and similar materials are disposed of by replacing the tailings in underground mineworks including the shafts, adits and drifts by forming a slurry of tailings using dredging or similar mixing processes and pumping the slurry to the mineworks. Cementitious materials may be added to selected quantities of the tailings slurries to form cement plugs for placement at selected intervals in the mineworks to minimize connectivity of the mineworks shafting, adits and drifts. The mineworks may be dewatered to provide a source of water for the slurrification process and the water may be reused after separation from the slurry. The disposal process provides a convenient way of replacing mine tailings in a repository of similar mineralogy and at least partially eradicates abandoned mineworks, including shafting, adits and drifts, which otherwise might require continual monitoring and dewatering.