Cyclic Injection Then Production Of A Single Well Patents (Class 166/263)
  • Patent number: 6484805
    Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: November 26, 2002
    Assignee: Alberta Research Council Inc.
    Inventors: Ernest H. Perkins, Douglas A. Lillico, Kevin Rispler
  • Patent number: 6457522
    Abstract: The present invention provides a clean water separation system with an electric submersible pumping device and a surface separator and pumping device for the separation and transfer of different density fluids and solids. The electric submersible pumping device can be an encapsulated device that works in conjunction with a separator and pumping system that are located on the surface, to separate fluids and solids.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: October 1, 2002
    Assignee: Wood Group ESP, Inc.
    Inventors: Yasser Khan Bangash, John Derek Jones, Michael R. Berry
  • Patent number: 6450256
    Abstract: A method of stimulating coalbed methane production by injecting gas into a producer and subsequently placing the producer back on production is described. A decrease in water production may also result. The increase in gas production and decrease in water production may result from: (1) the displacement of water from the producer by gas; (2) the establishment of a mobile gas saturation at an extended distance into the coalbed, extending outward from the producer; and (3) the reduction in coalbed methane partial pressure between the coal matrix and the coal's cleat system.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: September 17, 2002
    Assignee: The University of Wyoming Research Corporation
    Inventor: Charles G. Mones
  • Publication number: 20020125010
    Abstract: A microemulsion comprising, (i) an oil phase, (ii) an aqueous phase comprising an aqueous solution of a water soluble oil field or gas field production chemical or an aqueous dispersion of a water dispersible oil field or gas field production chemical and (iii) at least one surfactant, wherein the aqueous phase is distributed in the oil phase in the form of droplets having a diameter in the range 1 to 1000 mn or in the form of microdomains having at least one dimension of length, breath or thickness in the range 1 to 1000 nm.
    Type: Application
    Filed: December 14, 2001
    Publication date: September 12, 2002
    Inventors: Ian Ralph Collins, Isabelle Vervoort
  • Patent number: 6431280
    Abstract: This patent relates to a process whereby a filter/seive is produced by injecting the interactive chemicals used to form gels and polymers at reservoir temperatures independently and sequentially into a well in such a manner that the chemicals only come into contact with each other at the desired depth of penetration in the formation. At this location in the reservoir, which can be determined by appropriate calculation, the injection is stopped and the intermixed and superimposed chemicals are allowed to react to form the filter/seive of a gel or polymer depending upon the nature of the individual chemicals injected.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: August 13, 2002
    Inventors: Geoffrey Stanley Bayliss, Paul Stuart Bayliss
  • Patent number: 6431279
    Abstract: An improved method for the chlorine dioxide treatment of oil and/or gas well bores is provided, which eliminates the need for costly and complex chlorine dioxide-generating equipment and yields very high concentrations of chlorine dioxide down hole. The preferred method involves the introduction of reactant(s) into a well and causing a reaction to generate chlorine dioxide in situ. Chlorite and hypochlorite ion sources (e.g., sodium chlorite and sodium hypochlorite) are introduced into the well along with an acid. The well may then be flushed with water to force the reactants and chloride dioxide downwardly to the well formation.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: August 13, 2002
    Assignee: Jacam Chemicals, L.L.C.
    Inventors: Gene H. Zaid, Donald W. Sanders
  • Patent number: 6412559
    Abstract: A process for recovering methane from a coal bed and/or sequestering a fluid more strongly adsorbing than methane (“SAG”) in a coal bed involves fracturing an injection well and cyclically injecting SAG with intervening shut-in periods. Even though the absolute permeability of the coal bed decreases with continued SAG sorption, the SAG injectivity, surprisingly and unexpectedly, increases while injecting SAG at pressures greater than reservoir pressure, but less than fracture pressure or fracture extension pressure. The increased injectivity is thought to be due to a reduction in near-well flow resistance.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: July 2, 2002
    Assignee: Alberta Research Council Inc.
    Inventors: William Daniel Gunter, Matthew John Mavor, David Hin-Sum Law
  • Patent number: 6405799
    Abstract: A process for in situ upgrading of a heavy hydrocarbon includes the steps of (a) positioning a well in a reservoir containing a heavy hydrocarbon having an initial API gravity of less than or equal to about 8; (b) injecting a light solvent into the well at reservoir conditions so as to provide an upgraded hydrocarbon in the reservoir, the upgraded hydrocarbon having an improved API gravity greater than the initial API gravity; and (c) producing the upgraded hydrocarbon from the well.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: June 18, 2002
    Assignee: Intevep, S.A.
    Inventors: Carlos Vallejos, Tito Vasquez, Gerson Siachoque, Ignacio Layrisse
  • Publication number: 20020056550
    Abstract: Gaseous and liquid carbon dioxide (CO2) are applied to a landfill well to penetrate the landfill under rapid pressurization and depressurization repeated in cycles, with or without leachate or fluid in the well. These cycles can be repeated until the CO2 flows more freely down a lower pressure gradient in the well into the landfill surrounding the well screen, creating fissures in the landfill which allow methane and other gases to enter the well, thereby significantly enhancing methane and other landfill gas recovery.
    Type: Application
    Filed: January 8, 2002
    Publication date: May 16, 2002
    Inventors: Steven Catanla, Neil Mansuy
  • Patent number: 6338386
    Abstract: Gaseous and liquid carbon dioxide (CO2) are applied to a landfill well to penetrate the landfill under rapid pressurization and depressurization repeated in cycles, with or without leachate or fluid in the well. These cycles can be repeated until the CO2 flows more freely down a lower pressure gradient in the well into the landfill surrounding the well screen, creating fissures in the landfill which allow methane and other gases to enter the well, thereby significantly enhancing methane and other landfill gas recovery.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: January 15, 2002
    Assignee: Subsurface Technologies
    Inventors: Steven Catania, Neil Mansuy
  • Patent number: 6305472
    Abstract: An enhanced oil recovery process uses an injectant containing water and an additive. The additive is an organic compound having a total of 1 to 10 carbons and at least one functional group containing a heteroatom. The additive is present at a concentration of between about 0.01% and about 20% by weight of the composition. The injectant is injected at a temperature of between about 100° F. to about 500° F. Hot water flooding with the additive provides enhanced oil recovery in medium to heavy oil reservoirs.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 23, 2001
    Assignee: Texaco Inc.
    Inventors: William C. Richardson, Kenneth R. Kibodeaux
  • Patent number: 6302206
    Abstract: A method for treating a gas well to prevent any fresh water, which may have condensed out of the gas stream, from damaging the gas producing formation during the shut-in period. The well is shut-in and then an additive, e.g. a salt, alcohol, etc., is injected into the well to convert any accumulated fresh water into an aqueous solution which will not damage the formation. The additive can be injected in solid form or as a solution.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: October 16, 2001
    Assignees: Vastar Resources, Inc., Atlantic Richfield Company
    Inventors: Scott James Wilson, Marvin Eugene Miller
  • Patent number: 6298918
    Abstract: The invention relates to a pneumatic system for lifting petroleum, for application in wells, which may be flowing or non-flowing wells, preferably with low productivity levels or with low static pressure. The system uses cyclic pressurization and depressurization of a petroleum storage chamber located in the lower portion of the well by the injection of gas to force the fluid which has accumulated in the storage chamber to be lifted via the production column. After the storage chamber has been emptied to a certain degree, it is depressurized to allow refilling. When the storage chamber is depressurized, the gas may be diverted to the annular space between the production column and an auxiliary lift tube, where it plays a part in increasing the height of the column of fluid which it is possible to lift. A control system is responsible for the cyclic nature of the operation.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: October 9, 2001
    Assignee: Petroleo Brasileiro S.A.-Petrobras
    Inventors: Zadson De Almeida Franco, Francisco Alberto Cerqueira De Oliveira
  • Publication number: 20010018975
    Abstract: An enhanced oil recovery process uses an injectant containing water and an additive. The additive is an organic compound having a total of 1 to 10 carbons and at least one functional group containing a heteroatom. The additive is present at a concentration of between about 0.01% and about 20% by weight of the composition. The injectant is injected at a temperature of between about 100° F. to about 500° F. Hot water flooding with the additive provides enhanced oil recovery in medium to heavy oil reservoirs.
    Type: Application
    Filed: November 20, 1998
    Publication date: September 6, 2001
    Inventors: WILLIAM C RICHARDSON, KENNETH R. KIBODEAUX
  • Patent number: 6280000
    Abstract: A method for removing water and producing methane from a subterranean coal seam. The method includes drilling a first substantially vertical well bore to the depth of the target coal seam, enlarging the bore of the vertical well at the depth of a target coal seam to provide an enlarged cavity, drilling an offset well intersecting the cavity substantially horizontally and then drilling through the cavity in order to drill substantially horizontal drainage well bores in the coal seam. The method may be used as a pre-mining step in conjunction with subterranean mining of the coal seam in order to remove methane and other dangerous gases and excess water from the coal seam in advance of mining operations.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: August 28, 2001
    Inventor: Joseph A. Zupanick
  • Publication number: 20010010432
    Abstract: Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.
    Type: Application
    Filed: February 20, 2001
    Publication date: August 2, 2001
    Applicant: CDX Gas, LLC, Texas limited liability company
    Inventor: Joseph A. Zupanick
  • Patent number: 6257334
    Abstract: A pair of vertically spaced, parallel, co-extensive, horizontal injection and production wells and a laterally spaced, horizontal offset well are provided in a subterranean reservoir containing heavy oil. Fluid communication is established across the span of formation extending between the pair of wells. Steam-assisted gravity drainage (“SAGD”) is then practised by injecting steam through the injection well and producing heated oil and steam condensate through the production well, which is operated under steam trap control. Cyclic steam stimulation is practised at the offset well. The steam chamber developed at the offset well tends to grow toward the steam chamber of the SAGD pair, thereby accelerating development of communication between the SAGD pair and the offset well. This process is continued until fluid communication is established between the injection well and the offset well.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: July 10, 2001
    Assignee: Alberta Oil Sands Technology and Research Authority
    Inventors: Ted Cyr, Roy Coates, Marcel Polikar
  • Patent number: 6244341
    Abstract: A cyclic or “huff and puff” enhanced oil recovery process utilizes purified nitrogen gas as the injection gas. The purified nitrogen gas is preferably generated near the well site by the use of a membrane separator. The resulting purified nitrogen gas comprises at least about 90% by volume nitrogen with the remaining gas mixture fraction being primarily oxygen. The producing well is shut in. The gas mixture is injected down through the well into the formation. The well is then shut in allowing the gas mixture to soak into the formation for a predetermined period of time of at least 7 days and in some cases as much as 180 days or more. Then the well is placed on production and additional hydrocarbons are produced back from the same well into which the nitrogen gas was injected.
    Type: Grant
    Filed: July 20, 1999
    Date of Patent: June 12, 2001
    Assignee: Nitrogen Oil Recovery Systems LLC
    Inventor: Bernard J. Miller
  • Patent number: 6244338
    Abstract: A method of stimulating coalbed methane production by injecting gas into a producer and subsequently placing the producer back on production is described. A decrease in water production may also result. The increase in gas production and decrease in water production may result from: (1) the displacement of water from the producer by gas; (2) the establishment of a mobile gas saturation at an extended distance into the coalbed, extending outward from the producer; and (3) the reduction in coalbed methane partial pressure between the coal matrix and the coal's cleat system.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: June 12, 2001
    Assignee: The University of Wyoming Research Corp.,
    Inventor: Charles G. Mones
  • Patent number: 6234183
    Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol.
    Type: Grant
    Filed: July 10, 2000
    Date of Patent: May 22, 2001
    Assignee: Atlantic Richfield Company
    Inventors: Albert F. Chan, William Mark Bohon, David J. Blumer, Kieu T. Ly
  • Patent number: 6230814
    Abstract: A method for producing hydrocarbons from a subterranean formation comprises injecting steam and an additive into the formation. The additive has at least one nonaqueous fluid, which is selected so that the evaporation temperature of the additive is within about ±150° C. of the steam temperature at the operating pressure. Suitable additives include C1 to C25 hydrocarbons, and combinations thereof. At least a portion of the additive condenses in the formation. The mobility of the hydrocarbons is greater than that obtained using steam alone under substantially similar formation conditions.
    Type: Grant
    Filed: October 14, 1999
    Date of Patent: May 15, 2001
    Assignee: Alberta Oil Sands Technology and Research Authority
    Inventors: Tawfik Noaman Nasr, Ezra Eddy Isaacs
  • Patent number: 6227296
    Abstract: This invention provides a method for reducing the water saturation in the near-well region. Along with various well treatment possibilities, one application of this invention increases the injectivity rate of a substantially nonaqueous fluid into a subterranean formation. The preferred embodiment uses this invention to increase the injectivity of solvent gas into an oil-bearing formation for enhancing the amount and/or rate of oil recovery from the formation. The method includes injecting a second fluid into the near-well region of the injection well to displace at least a portion of the water from that region. Displacement of the water and subsequent displacement of the secondary fluid allow maximum injectivity for the primary solvent being injected for oil recovery.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: May 8, 2001
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Todd R. Reppert, W. Keith Idol
  • Patent number: 6220352
    Abstract: A process for restoring the injectivity or productivity of a well penetrating a subterranean formation by injecting a micelle treating fluid into the subterranean formation via the well with the micelle treating fluid containing a 2% potassium chloride water solution and a mutual solvent containing alcohol, aromatic hydrocarbon and an alkyl or alkylaryl polyoxyalkylene phosphate ester surfactant, thereafter displacing the micelle treating fluid into the formation by injecting a gas into the well and contacting accumulated asphaltene precipitate and a low-gravity, high-viscosity, asphaltene-based crude in the subterranean formation with the micelle treating fluid to disperse the accumulation of asphaltene and to reduce the viscosity of the low-gravity, high-viscosity, asphaltene-based crude.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: April 24, 2001
    Assignee: ETechMM
    Inventor: William B. Walton
  • Patent number: 6148913
    Abstract: This invention is a process and a formulation for minimising the squeezing and shut-in operations needed to inhibit scale in a production well using the precipitation squeeze method by injecting into an oil-bearing rock formation a water-miscible formulation comprising: (a) a water-miscible surfactant which is in liquid form, (b) a solution of water-soluble metal salt comprising a multivalent cation and (c) a solution of a water-miscible scale-inhibiting compound comprising an anionic component capable of forming a scale-inhibiting precipitate in situ in the presence of the cations in (b) upon injection into the rock formation, wherein the surfactant is a glycol ether and the minimum ion concentration of the scale inhibiting compound (c) is 50 ppm based on the total weight of the formulation.
    Type: Grant
    Filed: August 4, 1998
    Date of Patent: November 21, 2000
    Assignee: BP Chemicals Limited
    Inventor: Ian Ralph Collins
  • Patent number: 6129148
    Abstract: Method for reducing the viscosity of clogging hydrocarbons in an oil well. The method utilizes a tube type heat exchanger enabling heated gases to pass through feed water coils to heat the water to a predetermined temperature and at a pressure which prevents any flashing or phase change of the feed water within the heat exchanger. From the heat exchanger the heated feed water passes through a conduit which empties into the oil well. The well is open to atmosphere so that the feed water undergoes a phase change or flashing when it is introduced into the oil well. The resulting combined steam and hot water reduce the viscosity of the hydrocarbons sufficiently to facilitate their flow out of the oil well.
    Type: Grant
    Filed: September 21, 1999
    Date of Patent: October 10, 2000
    Inventor: Thomas Meeks
  • Patent number: 6119778
    Abstract: A method is disclosed for recovering methane from a solid carbonaceous subterranean formation having a production well in fluid communication with the formation and an injection well in fluid communication with the formation. In the method an oxygen-depleted effluent, produced by a cryogenic separator is injected into the formation through the injection well. A first methane-containing gaseous mixture is recovered from the formation through the production well-during at least a portion of the time the oxygen-depleted effluent is being injected into the formation. The first methane-containing gaseous mixture has a first methane-desorbing gas volume percent. The injection of oxygen-depleted effluent is ceased and thereafter a second methane-containing gaseous mixture is recovered from the formation which has a second methane-desorbing gas volume percent which is less than the first methane-desorbing gas volume percent.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: September 19, 2000
    Assignee: BP Amoco Corporation
    Inventors: John P. Seidle, Dan Yee, Rajen Puri
  • Patent number: 6050335
    Abstract: A system for in-situ production of bitumen comprises a steam injection well system which comprises a number of lateral sections that traverse the bitumen bearing formation partly above a basal water transition and/or thief zone such that a tip of each lateral section protrudes from the bitumen bearing formation into the basal water transition and/or thief zone.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: April 18, 2000
    Assignee: Shell Oil Company
    Inventor: Leslie James Parsons
  • Patent number: 6039116
    Abstract: A method and apparatus for operating a well which has a wellbore which passes into both an oil and gas production zone and a gas injection zone. An oil and gas stream is produced from the production zone through the wellbore to the surface where gas is separated from the oil. After production is shut-in, gas is mixed with a carrier fluid at the surface to form a dense mixture which, in turn, is flowed down the same wellbore and through a downhole auger separator wherein a portion of the gas is separated from the mixture. The separated gas is injected into the injection zone with the remainder of the mixture being returned to the surface. At the conclusion of the injection cycle, the well is returned to production and, if desired, the process is repeated.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: March 21, 2000
    Assignee: Atlantic Richfield Company
    Inventors: Mark D. Stevenson, Jerry L. Brady
  • Patent number: 6035933
    Abstract: A process for the thermo-hydraulic control of gas hydrates in subsea production and injection wells as well as pipelines which transport liquid or gaseous hydrocarbons is described, the process making use of a Nitrogen Generating System foamed or in solution. The control may signify the prevention of the formation of the gas hydrates or the dissolution of the gas hydrate plug already formed. Under conditions of use designed for the prevention of the formation of gas hydrates the SGN fluid prevents the thermal conditions leading to the gas hydrate plugs. Under conditions of use designed to dissolve the already formed gas hydrate plugs, the SGN fluid alters the thermo-hydraulic conditions which favor the gas hydrate plugs, so that they are dissolved and return to the water+gas phase.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: March 14, 2000
    Assignee: Petroleo Brasileiro S.A.-Petrobras
    Inventors: Carlos Nagib Khalil, Nelson De Oliveira Rocha, Lucia Cristina Ferreira Leite
  • Patent number: 5996692
    Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: December 7, 1999
    Assignee: Atlantic Richfield Company
    Inventors: Albert F. Chan, William Mark Bohon, David J. Blumer, Kieu T. Ly
  • Patent number: 5967233
    Abstract: A method for increasing the production of methane from a subterranean carbonaceous formation by chemically stimulating the formation of additional free surface area or cleats in the organic constituents of the formation and by causing inorganically adsorbed methane to be released from contained clay-minerals to increase the rate of methane desorption from the formation by injecting an aqueous oxidizing solution containing at least one oxidant into the formation, and thereafter producing methane from the formation at an increased rate. Suitable oxidants include peroxide, ozone, oxygen, chlorine dioxide, sodium hypochloride, water soluble salts of hypochlorous acid, perchlorate, chlorate, persulfate, perborate, percarbonate, permanganate, nitrate and combinations thereof.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: October 19, 1999
    Assignee: Vastar Resources, Inc.
    Inventors: Walter C. Riese, Stephen V. Bross
  • Patent number: 5964290
    Abstract: A method for increasing the production of methane from a subterranean coal formation by chemically stimulating the formation of cleats in the formation to increase the rate of methane production from the formation by injecting an aqueous oxidant solution into the formation to stimulate the formation of cleats in the formation; and thereafter producing methane from the formation at an increased rate. Suitable oxidants include chlorine dioxide, metallic salts of perchlorate, chlorate, persulfate, perborate, percarbonate, permanganate, nitrate and combinations thereof.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: October 12, 1999
    Assignee: Vastar Resources, Inc.
    Inventors: Walter C. Riese, Stephen V. Bross
  • Patent number: 5944104
    Abstract: A method for increasing the methane recovery from a subterranean carbonaceous formation by chemically stimulating the formation of cleats and increasing the surface area in the carbonaceous formation by injecting a gaseous oxidant into the carbonaceous formation to stimulate the formation of cleats in and increase the surface area of carbonaceous material in the carbonaceous formation; and thereafter producing methane from the carbonaceous formation at an increased rate. The gaseous oxidant may be ozone, oxygen or combinations thereof.
    Type: Grant
    Filed: October 16, 1997
    Date of Patent: August 31, 1999
    Assignee: Vastar Resources, Inc.
    Inventors: Walter C. Riese, Stephen V. Bross
  • Patent number: 5942469
    Abstract: A composition for and an improved process of, enhancing petroleum recovery from a petroleum reservoir by injecting said composition into the reservoir through a wellbore are provided. The aqueous composition is derived from a concentrate which includes a defoaming agent, a demulsifying agent, and optionally a stabilizing agent suitable for stabilizing the concentrate as an aqueous emulsion. In one embodiment, the defoaming agent is dispersed in carrier solvent and the concentrate further includes an emulsifying agent suitable for emulsifying the carrier solvent in water. The composition is preferably injected at a high pumping rate directly into the formation through the tubing-casing annulus and allowed to permeate into the reservoir surrounding the wellbore before oil production commences. The composition and method are particularly suited for used in conjunction with steam injection oil recovery techniques.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: August 24, 1999
    Assignee: Chevron U.S.A. Inc.
    Inventors: Max S. Juprasert, Bruce W. Davis
  • Patent number: 5871048
    Abstract: A method is provided for automatically determining an optimum gas injection rate for a gas-lifted oil well. The optimum gas-lift slope for the oil well is initially provided and stored in the memory of a programmable logic controller. A lift gas is injected into the well at an initial gas injection rate to displace a liquid at an initial liquid production rate from the well. The initial liquid production rate and initial gas injection rate are stored in the memory. Thereafter, the lift gas is injected into the well at a first incremental gas injection rate differing from the initial gas injection rate by a first incremental value. Additional liquid is displaced from the well at a first incremental liquid production rate and the first incremental liquid production rate and first incremental gas injection rate are stored in the memory. The first incremental slope is determined from the stored data points and compared to the optimum gas-lift slope.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: February 16, 1999
    Assignee: Chevron U.S.A. Inc.
    Inventors: Timothy J. Tokar, Brian E. Smith
  • Patent number: 5865248
    Abstract: A method for increasing the permeability to methane of a subterranean coal formation by chemically stimulating the coal formation by injecting a gaseous oxidant into the coal formation and thereafter producing methane from the coal formation at an increased rate. The gaseous oxidant is ozone, oxygen or combinations thereof. The completion of wells penetrating a subterranean coal formation is facilitated by injecting a gaseous oxidant into the coal formation surrounding the well prior to forming a cavity in the coal formation around the well.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: February 2, 1999
    Assignee: Vastar Resources, Inc.
    Inventors: Walter C. Riese, Stephen V. Bross
  • Patent number: 5860475
    Abstract: A thermal oil recovery process is disclosed for use in a heavy oil reservoir having a plurality of laterally separated, generally vertical wells whose use have left the reservoir characterized by a heated depletion zone, a channel, voidage, or mobility and communication. The process includes the steps of: drilling a well having a horizontal section and an opening therein that is located laterally between at least two of the vertical wells and at a depth within the lower part of the reservoir; injecting a steam through the two vertical wells to establish thermal communication with said horizontal well; and using the combination of steam drive and gravity drainage to recover oil from the reservoir through the horizontal well.
    Type: Grant
    Filed: December 8, 1994
    Date of Patent: January 19, 1999
    Assignee: Amoco Corporation
    Inventors: Godwin Ejiogu, Paul R. Sander, William J. McCaffrey
  • Patent number: 5803171
    Abstract: A method of producing hydrocarbons from a subterranean formation.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: September 8, 1998
    Assignee: Amoco Corporation
    Inventors: William J. McCaffery, Grant W. Boyd, Andrew J. Fox, Wayne P. Kraus, Bryan D. Weir
  • Patent number: 5769165
    Abstract: A method for increasing the production of methane from a subterranean coal formation penetrated by an injection well and a production well by producing methane from the coal formation via the production well; passing a portion of the methane to a synthesis gas generation zone wherein at least a portion of the methane is reacted with an oxygen-containing gas to produce a mixture of carbon monoxide and hydrogen; passing a major portion of the mixture to a hydrocarbon synthesis zone wherein the carbon monoxide and hydrogen are reacted to produce heavier hydrocarbons and a tail gas comprising nitrogen and carbon dioxide; separating a major portion of the tail gas from the hydrocarbons and recovering the hydrocarbons as a product stream; injecting at least a portion of the tail gas into the coal formation through the injection well. The methane may be obtained from a single well or a plurality of wells operated to produce the methane by a huff and puff process.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: June 23, 1998
    Assignee: Vastar Resources Inc.
    Inventors: Stephen V. Bross, Vu P. Dinh
  • Patent number: 5725054
    Abstract: A method for recovering oil from a subterranean formation penetrated by a well is provided, comprising the steps of injecting via the well a gas mixture into the formation, the gas mixture comprising carbon dioxide and a gas selected from the group consisting of methane, nitrogen, or mixtures thereof; wherein the gas mixture is injected in an amount sufficient to establish in the vicinity of the well a zone of oil in contact with the gas mixture; and wherein the carbon dioxide comprises about 5 percent to about 50 percent by volume at reservoir conditions of the gas mixture; shutting in the well for a predetermined period of time; and producing the well and recovering the residual oil from the formation.
    Type: Grant
    Filed: August 21, 1996
    Date of Patent: March 10, 1998
    Assignee: Board of Supervisors of Louisiana State University and Agricultural & Mechanical College
    Inventors: Sara Shayegi, Philip A. Schenewerk, Joanne M. Wolcott
  • Patent number: 5713416
    Abstract: The present invention provides methods of decomposing gas hydrates in subsea or subterranean wells, the equipment associated with the wells and in subterranean reservoirs containing gas hydrates. The methods basically comprise the steps of combining an acidic liquid with a basic liquid which chemically react exothermically to form a hot salt solution, contacting the gas hydrates with the hot salt solution to decompose at least a portion of the gas hydrates whereby natural gas and water are released therefrom and recovering the released natural gas, water and salt solution.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: February 3, 1998
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Jiten Chatterji, James E. Griffith
  • Patent number: 5669444
    Abstract: A method for increasing the production of methane from a subterranean coal formation by chemically stimulating the formation of cleats in the coal formation in order to facilitate removal of formation water, and increase the rate of methane production from the coal formation is disclosed. The method comprises injecting an aqueous oxidant solution into the coal formations to stimulate the formation of cleats in the coal formation; and thereafter producing methane from the coal formations at an increased rate. The aqueous oxidant solution comprises hypochlorite, metallic salts of hypochlorous acid, hydrogen peroxide, ozone, oxygen and combinations thereof.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: September 23, 1997
    Assignee: Vastar Resources, Inc.
    Inventors: Walter C. Riese, Stephen V. Bross
  • Patent number: 5626191
    Abstract: A well arrangement is used wherein the production wells are generally horizontal, positioned low in the reservoir and arranged generally perpendicularly to a laterally extending combustion front. The combustion front is propagated by a row of vertical air injection wells completed high in the reservoir. The open production wells function to cause the combustion front to advance along their lengths. The process is characterized by a generally upright combustion front having good vertical and lateral sweep.
    Type: Grant
    Filed: June 23, 1995
    Date of Patent: May 6, 1997
    Assignee: Petroleum Recovery Institute
    Inventors: Malcolm Greaves, Alexandru T. Turta
  • Patent number: 5607016
    Abstract: A method for the recovery of hydrocarbons from a reservoir of hydrocarbons including injecting a hydrocarbon solvent into the reservoir along with a displacement gas to mobilize hydrocarbons in the reservoir of hydrocarbons; and producing mobilized hydrocarbons from the reservoir of hydrocarbons. The hydrocarbon solvent is injected along one or more predominantly horizontal injection wells in the aquifer that are spaced from the production well or wells. The hydrocarbon solvent is a hydrocarbon solvent selected from the group consisting of ethane, propane, butane.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: March 4, 1997
    Inventor: Roger M. Butler
  • Patent number: 5601144
    Abstract: A multi-point recovery system for recovering fluid from a plurality of wells, including a pumping apparatus which connects a suction pump sequentially to different wells or groups of wells. The apparatus includes a row of ports in a surface above which a carriage moves on wheels to connect the suction pump to different ports or groups of ports in turn. Hoses are inserted into each well and connect to the ports. The hoses have a high point near the well providing a gravity trap to prevent recovered fluid from running back into the well. The wells may be sealed at the top to allow pumping of soil air.
    Type: Grant
    Filed: July 24, 1995
    Date of Patent: February 11, 1997
    Assignee: Geo & Hydro International Pty. Ltd.
    Inventor: Ben Keet
  • Patent number: 5566756
    Abstract: A method for treating a mixture of gaseous fluids within a solid carbonaceous subterranean formation. In some embodiments, the invention provides for the disposal of a strongly adsorbing gaseous fluid within the formation. In other embodiments, the invention provides a means for fractionating a mixture of gaseous fluids within the formation. In still other embodiments, the invention provides for the recovery of a raffinate from the formation which is enriched in relatively weaker adsorbing gaseous fluids. In still other embodiments, the invention provides for the recovery of methane from the formation.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: October 22, 1996
    Assignee: Amoco Corporation
    Inventors: Joseph J. Chaback, Dan Yee, Richard F. Volz, Jr., John P. Seidle, Rajen Puri
  • Patent number: 5566755
    Abstract: A method is disclosed for recovering methane from a solid carbonaceous subterranean formation having a production well in fluid communication with the formation and an injection well in fluid communication with the formation. In the method an oxygen-depleted effluent, produced by a cryogenic separator is injected into the formation through the injection well. A first methane-containing gaseous mixture is recovered from the formation through the production well during at least a portion of the time the oxygen-depleted effluent is being injected into the formation. The first methane-containing gaseous mixture has a first methane-desorbing gas volume percent. The injection of oxygen-depleted effluent is ceased and thereafter a second methane-containing gaseous mixture is recovered from the formation which has a second methane-desorbing gas volume percent which is less than the first methane-desorbing gas volume percent.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: October 22, 1996
    Assignee: Amoco Corporation
    Inventors: John P. Seidle, Dan Yee, Rajen Puri
  • Patent number: 5547022
    Abstract: A composition for, and an improved process of, enhancing petroleum recovery from a petroleum reservoir by injecting said composition into the reservoir through a wellbore are provided. The aqueous composition is derived from a concentrate which includes a defoaming agent, a demulsifying agent, and optionally a stabilizing agent suitable for stabilizing the concentrate as an aqueous emulsion. In one embodiment, the defoaming agent is dispersed in carrier solvent and the concentrate further includes an emulsifying agent suitable for emulsifying the carrier solvent in water. The composition is preferably injected at a high pumping rate directly into the formation through the tubing-casing annulus and allowed to permeate into the reservoir surrounding the wellbore before oil production commences. The composition and method are particularly suited for used in conjunction with steam injection oil recovery techniques.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: August 20, 1996
    Assignee: Chevron U.S.A. Inc.
    Inventors: Max S. Juprasert, Bruce W. Davis
  • Patent number: 5542474
    Abstract: The invention is a foam method for improving conformance during a steam flood or carbon dioxide flood in a subterranean, oil-containing formation penetrated by at least one injection well and at least one production well. In a steam flood oil recovery process, sweep efficiency is improved by injecting steam until steam breakthrough occurs at the production well after which a mixture of steam, a noncondensible gas, and an aqueous surfactant-polypeptide solution is injected into the formation. The aqueous surfactant-polypeptide solution forms a stable foam with the formation oil at formation conditions that reduce the permeability of the highly permeable steam swept zones thereby diverting the steam to other portions of the formation containing unswept oil. The polypeptide is used as a partial substitute for the surfactant to improve the cost of the foam-forming mixture without reducing its effectiveness in increasing sweep efficiency.
    Type: Grant
    Filed: December 4, 1995
    Date of Patent: August 6, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Nizar F. Djabbarah, Ralph V. Garling, David T. Hand, Jennifer Macfadyen
  • Patent number: 5513705
    Abstract: The invention is a foam method for improving conformance during a steam flood or carbon dioxide flood in a subterranean, oil-containing formation penetrated by at least one injection well and at least one production well. In a steam flood oil recovery process, sweep efficiency is improved by injecting steam until steam breakthrough occurs at the production well after which a mixture of steam, a noncondensible gas, and an aqueous surfactant-polypeptide solution is injected into the formation. The aqueous surfactant-polypeptide solution forms a stable foam with the formation oil at formation conditions that reduce the permeability of the highly permeable steam swept zones thereby diverting the steam to other portions of the formation containing unswept oil. The polypeptide is used as a partial substitute for the surfactant to improve the cost of the foam-forming mixture without reducing its effectiveness in increasing sweep efficiency.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: May 7, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Nizar F. Djabbarah, Ralph V. Garling, David T. Hand, Jennifer Macfadyen