Patents Assigned to Texaco Exploration Canada Ltd.
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Patent number: 4149597Abstract: Disclosed is a method for generating steam from water containing high concentrations of particulate matter such as silt, clay, etc., without the need for filtering and otherwise treating the water prior to generation of steam therefrom, especially useful for use in a viscous oil recovery process. The method comprises introducing solid particulate materials such as coarse sand, etc., into a thermal cracking unit such as, for example, that is used in the Lurgi-Ruhrgas process. The solids are heated to a temperature of at least 1400.degree. F., and on contacting the crude, cause cracking of the viscous crude into lighter molecular weight hydrocarbons and form a solid coke-like residue on the sand grain. The sand grains containing the coke residue are transported into a second chamber into which air is injected and the solid coke residue ignited. The carbon coke residue burns, raising the temperature of the sand or other granular solids.Type: GrantFiled: December 27, 1977Date of Patent: April 17, 1979Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 4143714Abstract: A method for measuring fluid advance in underground formations comprises, (1) driving bench marks into the ground over the formation spaced a predetermined distance apart, (2) measuring and recording the precise vertical displacement of each bench mark at the end of each predetermined period of time, and (3) interconnecting bench marks of similar vertical displacements to form lines, each line indicating the position of the passing of a particular amount of fluid in the formation underground at a particular time.Type: GrantFiled: August 19, 1977Date of Patent: March 13, 1979Assignee: Texaco Exploration Canada Ltd.Inventor: George H. Agnew
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Patent number: 4127172Abstract: Viscous petroleum may be recovered from viscous petroleum-containing formations such as tar sand deposits in a process employing steam and air or a free oxygen-containing gas in the ratio of 0.05 to 0.65 M.S.C.F. per bbl. and a cyclical injection-production program in which first steam or steam and air are injected and fluids are produced without restriction until live steam is produced at the production well, after which steam and air are injected and production throttled to a value less than 50% and preferably less than 20% until the formation pressure at the production well rises to a value between about 60% to 95% of the steam injection pressure, after which fluid production is permitted without restriction and steam and air injection is reduced to a value less than 50% and preferably less than 20% of the original injection rate. The process should be applied to a formation in which adequate communication exists or in which a communication path is first established.Type: GrantFiled: September 28, 1977Date of Patent: November 28, 1978Assignee: Texaco Exploration Canada Ltd.Inventors: David A. Redford, Phillip J. Cram
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Patent number: 4127170Abstract: Viscous petroleum may be recovered from formations in a process employing steam and a light hydrocarbon, and a cyclical injection-production program comprising repetitive cycles, each comprising three steps. First steam or steam and hydrocarbons are injected and liquids are recovered from the formation without restriction so long as no vapor phase steam production occurs. Next, steam and hydrocarbons are injected and production throttled until the formation pressure at the production well rises to a value between about 60% to 95% of the steam injection pressure, after which fluid production is permitted without restriction and steam and hydrocarbon injection rate is reduced to 50% or less of the original injection rate. The process should be applied to a formation in which adequate communication exists. Suitable hydrocarbons include C.sub.3 through C.sub.12 paraffinic or olefinic hydrocarbons including natural mixture such as naphtha, natural gasoline, etc.Type: GrantFiled: September 28, 1977Date of Patent: November 28, 1978Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 4124072Abstract: Disclosed is method for treating a high permeabiity communication channel between wells for use in a viscous oil recovery method to stabilize fine particulate matter present in the communication channel to prevent movement of fine particles during the oil recovery process. The communication channel is formed by fracturing or sweeping with air followed by introducing a viscous oil displacing medium such as a solvent or steam to desaturate the previously fractured or air swept zone in the formation, converting it into a high permeability channel between wells. In order to stabilize the fine grain sand and other minerals present in the communication channel to prevent migration thereof which results in loss of permeability of the communication channel, the channel is treated with a hydroxy aluminum solution and allowed to age for a period of time sufficient to form crystalline aluminum hydroxide which cements the grains together while maintaining permeability of the communication channel.Type: GrantFiled: December 27, 1977Date of Patent: November 7, 1978Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 4114690Abstract: An improved method for the recovery of heavy oils and bitumen from subterranean formations by the injection thereinto of a mixture of an oxygen-containing gas and steam in which the ratio of free oxygen in the gas to steam is in the range of 0.03 to 0.13 MSCF/bbl.Type: GrantFiled: June 6, 1977Date of Patent: September 19, 1978Assignee: Texaco Exploration Canada Ltd.Inventors: Phillip J. Cram, David A. Redford
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Patent number: 4109720Abstract: Petroleum may be recovered from viscous petroleum-containing formations including tar sand deposits by injecting into the formation a solvent which is liquid at formation conditions and simultaneously therewith injecting a substance which will remain totally gaseous at the pressure and temperature conditions existing within the reservoir. The presence of noncondensible gas in the formation into which solvent is being injected prevents formation of a impremeable bitumen bank which blocks the further flow of fluids through the formation. The gas should be essentially unreactive with the solvent and formation fluids in order to obtain the desired benefits. Examples of suitable gases for the practice of this invention include methane, ethane, nitrogen, carbon dioxide, and mixtures thereof.Type: GrantFiled: November 9, 1976Date of Patent: August 29, 1978Assignees: Texaco Inc., Texaco Exploration Canada, Ltd.Inventors: Joseph C. Allen, David A. Redford
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Patent number: 4105049Abstract: An abrasive resistant choke assembly. It is especially for use in withstanding the abrasive action of sharp particles of silt and sand that are carried by hot fluids flowing under pressure from producing wells. It includes a choke passage with an inlet end that has an angle of taper of less than 8.degree..Type: GrantFiled: December 15, 1976Date of Patent: August 8, 1978Assignee: Texaco Exploration Canada Ltd.Inventor: Clarence E. Anderson
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Patent number: 4099566Abstract: Solid hydrocarbon materials remaining in a subsurface earth formation such as, for example, the coke residue remaining in a subterranean tar sand deposit which has previously been exploited by means of a controlled oxidation process, is reignited and an oxygen-containing gas such as air is injected to burn the coke residue, thereby increasing the temperature of the sand or other formation matrix substantially. Water is then injected into the formation to absorb heat from the hot sand or formation matrix. Hot water and/or steam is thereby generated for use in thermal oil recovery methods in the immediate vicinity without the need for burning natural gas or other fuels which can be used more advantageously.Type: GrantFiled: March 4, 1977Date of Patent: July 11, 1978Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 4086961Abstract: A method for the recovery of hydrocarbons from a subterranean hydrocarbon-bearing reservoir by an enriched gas drive wherein lean gas, evolved from the miscible transition zone, is produced ahead of the miscible transition zone and reinjected behind the solvent injection point whereby excessive gas production is utilized and a drive agent miscible with the solvent is provided to displace the reservoir fluids through the reservoir to a production well from which they are produced.Type: GrantFiled: January 10, 1977Date of Patent: May 2, 1978Assignees: Texaco Inc., Texaco Exploration Canada Ltd.Inventors: William B. Braden, Jr., George H. Agnew
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Patent number: 4058453Abstract: A process for recovering oil from either water-bituminous petroleum emulsions or from crude petroleum emulsions having a pH of 10 or less by adding thereto an optimum amount of non-ionic, water soluble polyethylene oxide polymers at a pH of 10 or less, and separating the oil from water. To resolve bituminous petroleum emulsions, the process is carried out at between 150.degree. F and 210.degree. F and a diluent is added to reduce the petroleum viscosity. The minimum effective concentration of the polymers used decreases as their molecular weight increases.In a modification of the process, an effective amount of an alkaline earth metal halide such as calcium chloride is added to improve coagulation and separation of any clay present.Type: GrantFiled: August 11, 1976Date of Patent: November 15, 1977Assignee: Texaco Exploration Canada Ltd.Inventors: Mahendra S. Patel, Aleksy Sacuta
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Patent number: 4046195Abstract: A method for the recovery of low API gravity viscous oils or bitumen from a subterranean formation by the injection of steam followed by a mixture of an oxygen-containing gas and steam until an optimum amount of gas has been injected, followed by injection of steam alone.Type: GrantFiled: June 18, 1975Date of Patent: September 6, 1977Assignee: Texaco Exploration Canada Ltd.Inventors: Phillip J. Cram, David A. Redford
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Patent number: 4026357Abstract: Solid hydrocarbon materials present in subsurface earth formation such as, for example, the coke like residue remaining in a subterranean tar sand deposit which has previously been exploited by controlled oxidation depletion, is converted to a synthesis gas composition by contacting the solid hydrocarbon material with an oxygen enriched gas or essentially pure oxygen and a moderating fluid such as water, steam or carbon dioxide to control the reaction temperature so as to ensure the generation of carbon monoxide and hydrogen within the formation. The oxygen and steam or carbon dioxide may be injected as a mixture or simultaneously by separate injection means, or oxygen may be injected for intervals of time interrupted by brief periods of carbon dioxide, steam or water injection. The effluent is predominantly gaseous carbon monoxide, hydrogen, and lesser amounts of carbon dioxide and methane and, occasionally liquid hydrocarbons.Type: GrantFiled: June 26, 1974Date of Patent: May 31, 1977Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 4006778Abstract: A method for the recovery of low API gravity viscous oils or bitumens from a subterranean formation by the injection of a mixture of an oxygen-containing gas and steam at a temperature corresponding to the temperature of saturated steam at the pressure of the formation.Type: GrantFiled: June 21, 1974Date of Patent: February 8, 1977Assignee: Texaco Exploration Canada Ltd.Inventors: David A. Redford, Stephen M. Creighton
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Patent number: 3996755Abstract: A tension leg marine structure or working platform which is floatably positioned above an offshore working site, being maintained in place by a plurality of tension cables that connect to anchors at the sea floor. A riser which extends between the structure and the sea floor is laterally supported by a bracing system adapted to adjust to the platform's movement and conditions, thereby to stabilize strain applied to the riser.Type: GrantFiled: July 10, 1975Date of Patent: December 14, 1976Assignee: Texaco Exploration Canada Ltd.Inventor: David W. Kalinowski
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Patent number: 3993132Abstract: A method for the recovery of low API gravity viscous oils or bitumen from a subterranean formation by the injection of a mixture of an oxygen-containing gas and steam having an optimum gas/steam ratio that is decreased as the cumulative amount of steam is increased.Type: GrantFiled: June 18, 1975Date of Patent: November 23, 1976Assignee: Texaco Exploration Canada Ltd.Inventors: Phillip J. Cram, David A. Redford
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Patent number: 3978925Abstract: A method for the recovery of low gravity viscous oils or bitumens from a subterranean formation by the injection of a mixture of an oxygen-containing gas and steam to establish a hot communications path, followed by a shutting in of the wells for a period to allow the oxygen to react with the oil or bitumen in the formation and thereafter recovering the oil or bitumens via the production well. The cycle may thereafter be repeated.Type: GrantFiled: June 21, 1974Date of Patent: September 7, 1976Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 3974877Abstract: This invention relates to a method for treating wells completed in subterranean formations to prevent the movement of unconsolidated sand particles from the formation into the well during recovery of formation fluid or away from the well during injection of an extraneous recovery fluid thereinto. The method is especially applicable to formations containing asphaltic or bituminous petroleum, such as tar sand deposits. In one embodiment, granular material such as sand or gravel is introduced into the formation adjacent to the well bore and saturated with bituminous or asphaltic petroleum. The bituminous petroleum naturally occurring in a tar sand material may be used, or bituminous petroleum may be pumped into the sand and gravel.Type: GrantFiled: June 26, 1974Date of Patent: August 17, 1976Assignee: Texaco Exploration Canada Ltd.Inventor: David A. Redford
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Patent number: 3951457Abstract: Viscous petroleum including bitumen may be recovered for subterranean petroleum containing unconsolidated said formations such as tar sand deposits by hydraulic mining. Hot water or steam is introduced into the subterranean deposit with sufficient velocity to dislodge bitumen and particles of sand therefrom. The process is a single wellbore operation using rotatable vertically moveable injection string with one or more jets near the bottom thereof, with separate return flow path to surface, the inlet to which may be on the bottom of the injection string. Injection string may be raised or lowered while rotating and jetting so full vertical thickness of tar sand interval is contacted by aqueous mining fluid. Jet pump may be used to pump petroleum to surface. Injected aqueous hydraulic mining fluid may contain alkaline material such as sodium hydroxide or ammonium hydroxide.Type: GrantFiled: December 7, 1973Date of Patent: April 20, 1976Assignee: Texaco Exploration Canada Ltd.Inventor: David Arthur Redford
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Patent number: 3938590Abstract: Disclosed is a process for recovering petroleum from subterranean, viscous asphaltic or bituminous petroleum-containing formations, including subterranean tar sand deposits. A zone of gas permeability is established in the formation first, such as by fracturing or gas sweeping a section of the formation. Oxidizing gas such as oxygen, air, oxygen enriched air, ozone, or chlorine, or a mixture of steam and an oxidizing gas is introduced into the zone of increased gas permeability to expand the zone and further to cause a reaction to occur between the oxidizing gas and the oxygen-susceptible groups or labile groups associated witn the bituminous or asphaltic petroleum molecules forming acidic or aldehyde groups. Next, a gaseous or liquid alkalinity agent such as ammonia is introduced into the formation to react with the oxidatively pre-treated groups in the bituminous or asphaltic petroleum to form surface active agents or surfactants in situ.Type: GrantFiled: June 26, 1974Date of Patent: February 17, 1976Assignee: Texaco Exploration Canada Ltd.Inventors: David A. Redford, David L. Mitchell