Organic Component Contains Nitrogen Attached Directly Or Indirectly To Carbon By Nonionic Bonding Patents (Class 507/129)
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Patent number: 6287646Abstract: A novel liquid crystal compound, a nematic liquid crystal composition, and a liquid crystal display system using the composition are disclosed herein. The liquid crystal compound is represented by the general formula (I): wherein R represents a hydrogen atom or a straight chain alkyl group having 1 to 7 carbon atoms and each of X, Y and Z independently represents hydrogen atom or fluorine atom. The nematic liquid crystal composition of the present invention can provide liquid crystal materials in response to desired purposes even by its addition in a small amount without spoiling other characteristics.Type: GrantFiled: November 30, 1998Date of Patent: September 11, 2001Assignee: Dainippon Ink and Chemicals, Inc.Inventors: Kiyofumi Takeuchi, Haruyoshi Takatsu, Sadao Takehara, Masashi Osawa
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Patent number: 6284714Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.Type: GrantFiled: July 29, 1999Date of Patent: September 4, 2001Assignee: Baker Hughes IncorporatedInventors: Ronald G. Bland, Lirio Quintero
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Publication number: 20010001991Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.Type: ApplicationFiled: January 10, 2001Publication date: May 31, 2001Applicant: M-I LLCInventors: Arvind D. Patel, Reginald J. Bell, Burhan Hoxha, Steve Young
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Patent number: 6239183Abstract: A method for controlling the rheology of aqueous systems, particularly for those intended for underground use, includes injecting an aqueous fluid containing a surfactant gelling agent into the system. The surfactant gelling agents are, for example, fatty aliphatic amidoamine oxides, salts of an alkoxylated monoamine with an aromatic dicarboxylic acid, and salts of an alkyldiamine with an aromatic dicarboxylic acid. The surfactant gelling agents can be adsorbed onto particulate supports to facilitate delivery of the gelling agent. The additives may be incorporated in the viscoelastic fluid to tailor its use in hydraulic fluids, drilling muds, fracture fluids, and in applications such as permeability modification, gravel packing, cementing, and the like.Type: GrantFiled: December 19, 1997Date of Patent: May 29, 2001Assignee: Akzo Nobel NVInventors: Robert F. Farmer, Andress K. Doyle, Glenda Del Carmen Vale, James F. Gadberry, Michael D. Hoey, Randy E. Dobson
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Patent number: 6218342Abstract: Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion.Type: GrantFiled: May 23, 1997Date of Patent: April 17, 2001Assignee: M-I LLCInventor: Avind D. Patel
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Patent number: 6211119Abstract: The invention relates to multiphase lubricant concentrates with improved properties for use in aqueous fluids for geological exploration by drilling which contain organic lubricating components which are solid and/or liquid at room temperature (O phase) together with emulsifiers finely dispersed in a continuous aqueous phase (W phase). These concentrates are characterized in that the system of O phase/W phase and emulsifiers has a phase inversion temperature (PIT) above room temperature and has been produced by heating the multiphase system to temperatures equal to or above the PIT and subsequent cooling to temperatures below the PIT. The present invention also relates to the use of the multiphase lubricant concentrates as an additive in water-based fluids for use in geological exploration by drilling and for the subsequent treatment of the resulting boreholes.Type: GrantFiled: June 1, 1999Date of Patent: April 3, 2001Assignee: Henkel Kommanditgesellschaft auf AktienInventors: Claus-Peter Herold, Heinz Mueller, Thomas Foerster, Stephan Von Tapavicza, Marcus Claas
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Patent number: 6187719Abstract: This invention is a process for improving the rheological properties of oil well drilling fluids particularly useful for oil-based invert emulsion types of drilling fluids. The process is particularly useful when drilling in deep water from an off-shore drilling rig. The new process uses as a rheological viscosifier, for such fluids, a composition which is a mixture of organoclays and castor wax and/or castor was type rheological additives, which when added to a drilling fluid at from about 0.5 and 5% by weight, creates an inventive drilling fluid compositions less sensitive to the variety of different and varying, very hot and very cold temperatures found in the drilling hole, and in the long stem of drilling pipe. The present invention also relates to the discovery of oil based invert emulsion drilling fluids that exhibit greater efficiency and provides more stable drilling fluid viscosity and anti-settling performance over varying temperatures when compared to conventional fluids containing organoclays.Type: GrantFiled: April 28, 1998Date of Patent: February 13, 2001Assignee: Rheox, Inc.Inventors: David Dino, Charles Cody, Edward Magauran, Araxi Chiavoni
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Patent number: 6172010Abstract: The invention concerns a water based foaming composition and the method of making it. The composition is optimized in that it contains a surfactant specifically selected according to the polymer also present in the composition. The surfactant and the polymer are selected so that they are oppositely charged. The invention is very useful in drilling or treating wells.Type: GrantFiled: September 22, 1998Date of Patent: January 9, 2001Assignee: Institut Francais du PetroleInventors: Jean-François Argillier, Annie Audibert-Hayet, Sabine Zeilinger
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Patent number: 5985800Abstract: New drilling fluids have been invented which are invert emulsion fluids comprising an oleaginous liquid, a non-oleaginous liquid, and a protonated amine. Such fluids are acidic and thus useful in drilling wells in which acidic gases such as CO.sub.2 or H.sub.2 S are likely to be encountered and break, i.e. de-emulsify, the drilling fluid.Type: GrantFiled: March 20, 1998Date of Patent: November 16, 1999Assignee: M-I L.L.C.Inventor: Arvind D. Patel
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Patent number: 5977031Abstract: An invert emulsion suitable for drilling subterranean wells, in particular oil and gas wells is disclosed which includes an oleaginous phase, and a non-oleaginous phase and a protonated amine surfactant which stabilizes the invert emulsion in the absence of an alkaline reserve material. The protonated amine surfactant has the general formula:[R--N.sup.+ --H.sub.3 ]B.sup.-wherein R is a C.sub.12 to C.sub.22 alkyl group and B.sup.- is a conjugate base of an acid; and the protonated amine surfactant is present in an amount capable of stabilizing the invert emulsion in the absence of an alkali reserve. The practice of the present invention permits the use of a broad range of esters as the oleaginous phase including simple alkyl esters which previously susceptible to hydrolysis due to the presence of an alkaline reserve material.Type: GrantFiled: August 7, 1998Date of Patent: November 2, 1999Assignee: M-I L.L.C.Inventor: Arvind D. Patel
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Patent number: 5972849Abstract: In the presence of certain crude oils, when ferric iron exists in very acidic fluid, it practically instantaneously forms precipitates known as sludges which lead to irreversible damage. Iron control compositions and acid fluids containing such iron control compositions are disclosed. For acid fluids containing up to 15% acid, the iron control composition includes a reducing agent selected from a substituted and unsubstituted thiourea compounds, and a reduction catalyst including a copper (cuprous or cupric) compound. When the acid fluid contains more than 15% acid, for example from 15 to 28% acid, the reducing agent is again selected from substituted or unsubstituted thiourea compounds, and the reduction catalyst is a combination of a copper (cuprous or cupric) compound and iodine (iodine or iodide ions).Type: GrantFiled: November 6, 1995Date of Patent: October 26, 1999Assignee: Schlumberger Technology CorporationInventors: Jean-Pierre Feraud, Herve Perthuis, Philippe Dejeux, Pierre Maroy
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Patent number: 5922652Abstract: Gelatin capsules containing oil field chemicals, preferably weighted with a heavy metal compound, are made more stable under certain conditions by the incorporation of a strong chelating agent. The microcapsules can provide an extended treatment period since many materials that would damage the microcapsules are controlled by the chelating agent.Type: GrantFiled: May 5, 1992Date of Patent: July 13, 1999Inventors: Thomas Charles Kowalski, Robert Wayne Pike
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Patent number: 5909779Abstract: An alkaline-reserve-free, oil-based drilling fluid is disclosed as comprising an oleaginous liquid, and an amine surfactant having the structure R-NH.sub.2, wherein R represents a C.sub.12 -C.sub.22 alkyl group or alkenyl group. Such fluid is particularly useful in the drilling of subterranean wells in which CO.sub.2, H.sub.2 S or other acidic gases which adversely effect the rheologies and other properties of the drilling fluid are encountered. The alkaline-reserve-free oil-based drilling fluid permits the logging of acidic gases which otherwise could not be logged in the presence of lime or other alkaline.Type: GrantFiled: June 30, 1998Date of Patent: June 8, 1999Assignee: M-I L.L.C.Inventors: Arvind D. Patel, Jayanti S. Patel, Harris A Oehler
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Patent number: 5905061Abstract: New drilling fluids have been invented which are invert emulsion fluids comprising an oleaginous liquid, a non-oleaginous liquid, and a protonated amine. Such fluids are acidic and thus useful in drilling wells in which acidic gases such as CO.sub.2 or H.sub.2 S are likely to be encountered and break, i.e. de-emulsify, the drilling fluid.Type: GrantFiled: May 23, 1997Date of Patent: May 18, 1999Inventor: Avind D. Patel
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Patent number: 5887653Abstract: There is provided an additive for and a method of using the additive to treat a clay-containing earthen formation, such as a subterranean formation, to substantially reduce formation damage caused by contact of the formation with an aqueous liquid foreign to the formation. The additive, which is employed in a water solution, is comprised of a chloride-free, quaternary ammonium compound which can be used without adverse affect upon animal, soil and water resources due to the chloride-free and substantial organic nature thereof. It thus biodegrades to environmentally acceptable end products.Type: GrantFiled: August 15, 1997Date of Patent: March 30, 1999Assignee: Plainsman Technology, Inc.Inventors: L. W. Bishop, Marlin D. Holtmyer
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Patent number: 5888944Abstract: A method of removing the filter cake formed from invert emulsion compositions including an oleaginous, a non-oleaginous and an acid sensitive surfactant in an oil and gas well are disclosed. The acid sensitive surfactant is selected so that the invert emulsion can be broken and residual filter cake solids made water-wet upon the addition of an acidic wash fluid to the well.Type: GrantFiled: June 23, 1997Date of Patent: March 30, 1999Assignee: MI L.L.C.Inventor: Arvind D. Patel
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Patent number: 5869433Abstract: The present invention relates to an oil-based drilling fluid, a continuous phase for an oil-based drilling fluid, and additives for an oil-based drilling fluid. The drilling fluid, the continuous phase of the drilling fluid, and the additives for the oil-based drilling fluid are characterized by non-fluorescence (defined as a fluorescence intensity of 800 or less) when exposed to ultraviolet light. The continuous phase of the drilling fluid is composed of synthetic hydrocarbons selected from the group consisting of oligomers synthesized from one or more alphaolefins containing a C.sub.2 to C.sub.14 chain length, wherein the oligomers have an average molecular weight of from 120 to 100, and additives. The additives of the continuous phase include surfactants, wetting agents and/or emulsifiers.Type: GrantFiled: August 30, 1995Date of Patent: February 9, 1999Assignee: M-I L.L.C.Inventor: Arvind D. Patel
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Patent number: 5858928Abstract: The invention relates to a gel made of apolar medium including:an apolar medium,a "multichain" liquid surface-active agent in acidic form, soluble or dispersible in the said apolar medium,an agent for neutralizing the said "multichain" surface-active agent,from 0.2 to 5 molecules of water per molecule of "multichain" surface-active agent,optionally at least one emulsifying agent and/or a solid filler which is soluble or insoluble in the apolar medium.This gel may be employed for the formulation of water-based drilling fluids.Type: GrantFiled: November 22, 1995Date of Patent: January 12, 1999Assignee: Rhone-Poulenc ChimieInventors: Daniel Aubert, Laurent Frouin, Mikel Morvan, Marie-Madeleine Vincent
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Patent number: 5853619Abstract: A low toxic corrosion inhibitor comprises (A) mercaptocarboxylic acid having from 2 to 6 carbon atoms, and (B) a polyamine/fatty acid/carboxylic acid adduct. The preferred combination of (A) and (B) includes mercaptoacetic acid and ethylenetetramine/tall oil acd/acrylic acid adduct.Type: GrantFiled: November 22, 1996Date of Patent: December 29, 1998Assignee: Nalco/Exxon Energy Chemicals, L.P.Inventors: James D. Watson, John G. Garcia, Jr.
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Patent number: 5710108Abstract: The invention involves biopolymer/oil suspension compositions for the oil service industry, most particularly drilling and completion fluids, which provide such fluids a variety of desirable properties. Biopolymers include water soluble polymers and water swellable polymers. Such biopolymer/oil suspension compositions are essentially mixtures of biopolymers such as cellulosics in an oil medium with a specific anti-settling additive. The invention is particularly directed to providing enhanced anti-settling properties to such biopolymer/oil compositions; that is, the ability of the biopolymer/oil composition to retain the biopolymers in suspension prior to the composition being introduced into drilling and completion fluids. The invention in one embodiment is described as a liquid biopolymer-in-oil additive compositions for use in aqueous-based completion fluids, containing an agent comprising: a) one or more polyamides, and b) hydrogenated caster oils including castorwax.Type: GrantFiled: April 5, 1996Date of Patent: January 20, 1998Assignee: Rheox, Inc.Inventors: Keith McNally, James Gambino, Charles Cody, Wilbur Mardis
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Patent number: 5677266Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.Type: GrantFiled: June 5, 1995Date of Patent: October 14, 1997Assignee: Institut Francais du PetroleInventors: Annie Audibert, Jacqueline Lecourtier, Louise Bailey, Geoffrey Maitland
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Patent number: 5635458Abstract: The present invention provides a water-based drilling fluid that reduces water adsorption and hydration of argillaceous rocks. The drilling fluid comprises a glycol with a molecular weight of less than about 200, an organic cationic material such as salts of choline or an organic salt of potassium, a filtration control agent, a viscosifier and water.Type: GrantFiled: March 1, 1995Date of Patent: June 3, 1997Assignee: M-I Drilling Fluids, L.L.C.Inventors: Li-Jein J. Lee, Arvind D. Patel
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Patent number: 5607904Abstract: The present invention provides nonionic alkanolamides which may be added to drilling fluids in order to minimize hydration and prevent erosion loss of water-sensitive shale substrates. Preferred alkanolamides are acetamide mono- and diethanolamines.Type: GrantFiled: April 13, 1995Date of Patent: March 4, 1997Assignee: Baker Hughes IncorporatedInventor: Michael Jarrett
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Patent number: 5593952Abstract: The present invention provides amphoteric acetates, diacetates, and glycinates which may be added to drilling fluids in order to minimize hydration and prevent erosion loss of water-sensitive shale substrates.Type: GrantFiled: April 12, 1995Date of Patent: January 14, 1997Assignee: Baker Hughes IncorporatedInventor: Michael Jarrett
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Patent number: 5558171Abstract: The invention relates to clay stabilizing agents for use in an alkaline water-base fluid such as a drilling mud and the use of such clay stabilizing agents in the drilling of wells. The clay stabilizing agent comprises a polyfunctional polyamine reaction product prepared by the reaction of a polyamine base reactant with urea or a dialkylcarbonate or by reaction with urea and a dialkylcarbonate. The stabilizing agent is subject to subsequent acidification to reduce the pH thereof to a value of about 7 or less. The polyamine base reactant is selected from the group consisting of an aliphatic polyamine, a polyaliphatic polyamine, a heterocyclic polyamine, an alkylalkanol polyamine and mixtures thereof. Specifically, the base reactant comprises an aliphatic polyamine selected from the group consisting of ethylenediamine, diethylenetriamine, tetraethylenetetramine, and tetraethylenepentamine and mixtures thereof.Type: GrantFiled: April 25, 1994Date of Patent: September 24, 1996Assignee: M-I Drilling Fluids L.L.C.Inventors: Raymond E. McGlothlin, Frank B. Woodworth
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Patent number: 5459125Abstract: A composition and method for inhibiting corrosion by chlorine dioxide in oil field water flood systems are disclosed. The composition is comprised of an alcohol, an acid, a fatty imidazoline, an ethoxylated fatty diamine, and water. This composition has proven more effective than chromates at inhibiting the corrosion caused by chlorine dioxide, further without the serious toxicological effects caused by the use of chromates.Type: GrantFiled: July 22, 1993Date of Patent: October 17, 1995Assignee: BJ Services CompanyInventors: James R. Ohlsen, J. Michael Brown, Gene F. Brock, Veena K. Mandlay
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Patent number: 5424284Abstract: This invention relates to drilling fluid additives that suppress clay swelling within a subterranean well and to methods for controlling clay swelling during the drilling of a subterranean well. In one embodiment trihydroxy alkyl amine is reacted with an alkyl halide or a water soluble quaternary amine to form a quaternized trihydroxy alkyl amine. The reaction products can also include condensed reaction products of quaternized trihydroxy alkyl amines. In another embodiment a choline derivative is used. The quaternized reaction products and choline derivatives are characterized by low toxicity and compatibility with anionic drilling fluid components. The products are added to water base drilling fluids which are circulated throughout a well. The drilling fluid additives and the method of controlling clay swelling provide for improved control of the rheological properties of drilling fluids along with increased environmental and drilling fluid compatibility.Type: GrantFiled: July 2, 1993Date of Patent: June 13, 1995Assignee: M-I Drilling Fluids CompanyInventors: Arvind D. Patel, Henry C. McLaurine
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Patent number: 5411670Abstract: A method and coating composition for producing protective coatings on metal surfaces of tubular goods, equipment and so forth used in processes associated with oxidative environments to inhibit corrosive effects of the oxidative environments thereon. The coating composition includes an aqueous liquid carrier and a corrosion inhibiting combination of a specific condensation product and an antimony compound. The antimony compound is activated by the condensation product and enhances the degree of protection achieved.Type: GrantFiled: July 26, 1993Date of Patent: May 2, 1995Assignee: Halliburton CompanyInventor: Michael L. Walker
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Patent number: 5403822Abstract: The invention describes the use of selected esters, fluid at room temperature and with flash points above 80.degree. C., from monocarboxylic acids of synthetic and/or natural origin with 6 to 11 carbon atoms and mono- and/or polyfunctional alcohols as the oil phase or a component of the oil phase of invert drilling muds, which are suitable for environment-friendly development of petroleum and natural gas deposits and in a continuous oil phase contain a dispersed aqueous phase together with emulsifiers, weighting agents, fluid-loss additives and preferably further conventional additives. In a further embodiment the invention relates to invert-drilling fluids of the types mentioned, which are characterized in that the oil phase contains esters of monocarboxylic acids of synthetic and/or natural origin with 6 to 11 carbon atoms and with mono- and/or polyfunctional alcohols preferably in admixture with other components from the class of ecologically acceptable compounds.Type: GrantFiled: May 27, 1993Date of Patent: April 4, 1995Assignee: Henkel Kommanditgesellschaft auf AktienInventors: Heinz Mueller, Claus-Peter Herold, Stephan von Tapavicza, Michael Neuss, Wolfgang Zoellner, Frank Burbach
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Patent number: 5380706Abstract: Improved well drilling fluids and methods which prevent damage to water sensitive formations while drilling are provided. The drilling fluids include a formation stabilizing compound which contains an organic quaternary ammonium cation and an inorganic, organic or combination anion.Type: GrantFiled: March 26, 1993Date of Patent: January 10, 1995Assignee: Halliburton CompanyInventors: Ronald E. Himes, Patty L. Totten, Edward E. Vinson
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Patent number: 5350740Abstract: This invention relates to drilling fluid additives that suppress clay swelling within a subterranean well and to methods for controlling clay swelling during the drilling of a subterranean well. A trihydroxy alkyl amine is reacted with an alkyl halide or a water soluble quaternary amine to form a quaternized trihydroxy alkyl amine. The reaction products can also include condensed reaction products of quaternized trihydroxy alkyl amines. The quaternized reaction products are characterized by low toxicity and compatibility with anionic drilling fluid components. The products are added to water base drilling fluids which are circulated throughout a well. The drilling fluid additives and the method of controlling clay swelling provide for improved control of the rheological properties of drilling fluids along with increased environmental and drilling fluid compatibility.Type: GrantFiled: May 7, 1993Date of Patent: September 27, 1994Assignee: M-1 Drilling Fluids CompanyInventors: Arvind D. Patel, Henry C. McLaurine
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Patent number: 5254531Abstract: In a first embodiment, the invention relates to the use of basic amine compounds of pronounced oleophilic character and at most limited solubility in water, which are capable of forming salts with carboxylic acids, as an additive for w/o invert drilling muds which contain in the continuous oil phase ester oils and, together with the disperse aqueous phase, emulsifiers, weighting agents, fluid loss additives and, if desired, other additives for protecting the drilling muds against unwanted thickening in use or for improving their flowability. In another embodiment, the invention relates to w/o invert drilling muds which are suitable for the improved offshore development of oil and gas sources and which are characterized by the presence of basic amine compounds of pronounced oleophilic character which are capable of forming salts with carboxylic acids.Type: GrantFiled: January 21, 1992Date of Patent: October 19, 1993Assignee: Henkel Kommanditgesellschaft auf AktienInventors: Heinz Mueller, Claus-Peter Herold, Stephan von Tapavicza
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Patent number: 5189012Abstract: The present invention relates to an improved continuous phase for an oil based drilling fluid and specifically a synthetic hydrocarbon continuous phase which is non-polluting and minimally toxic. The invention provides excellent drilling fluid properties under a wide variety of drilling conditions. The synthetic hydrocarbons are selected from the group consisting of branched chain oligomers synthesized from one or more olefins containing a C.sub.2 to C.sub.14 chain length and wherein the oligomers have an average molecular weight of from 120 to 1000. In the drilling fluid compositions, suitable emulsifiers, wetting agents, viscosifiers, weight materials and fluid loss additives are utilized in conjunction with water and/or a brine phase for the desired rheological properties.Type: GrantFiled: June 8, 1990Date of Patent: February 23, 1993Assignee: M-I Drilling Fluids CompanyInventors: Arvind D. Patel, Raymond E. McGlothlin, Roger D. Bleier, H. N. Brinkley
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Patent number: 5106516Abstract: The invention relates to the use of methylesters of C.sub.6-24 monocarboxylic acids as the oil phase or as part of the oil phase of invert drilling muds which are suitable for the environment-friendly development of oil and gas sources and which, in a continuous oil phase, contain a disperse aqueous phase together with emulsifirs, weighting agents, fluid loss additives and, if desired, other standard additives. In another embodiment, the invention relates to invert drilling muds which are particularly suitable for the environment-friendly development of oil and gas sources and which are characterized in that the oil phase contains methylesters of C.sub.6-24 monocarboxylic acids, if desired in admixture with other oil components from the class of non-polluting oils.Type: GrantFiled: February 9, 1990Date of Patent: April 21, 1992Assignee: Henkel Kommanditgesellschaft auf AktienInventors: Heinz Mueller, Claus-Peter Herold, Stephan von Tapavicza
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Patent number: 5076852Abstract: A cement method and composition for cementing a well penetrating subterranean formations and aqueous based drilling fluid containing at least one cement retarder characterized by a major proportion of the drilling fluid from the well as it was drilled; water; a lesser proportion of dry cementitious material; a minor amount of a dispersant that does not effect satisfactory set cement within an acceptable time interval; and an accelerator selected from the class consisting of acetic acid; the first 4 carbon esters thereof; acetamide; monoethanolamine; and diethanolamine. The first 4 carbon esters are the methyl; ethyl; propyl, both normal and isopropyl; and butyl ester, normal, isobutyl and tertiary butyl.Type: GrantFiled: April 29, 1991Date of Patent: December 31, 1991Assignee: Atlantic Richfield CompanyInventors: James B. Bloys, William N. Wilson, Roger D. Bradshaw