Abstract: This invention relates to improved methods for completing wells in unconsolidated subterranean zones. More specifically, the present invention relates to cement compositions useful in subterranean applications, and more particularly, to permeable cement compositions and methods for forming consolidated permeable cement masses in well bores to prevent sand influx into the well bores with produced fluids. In one embodiment, the permeable cement compositions of the present invention comprise a hydraulic cement, water, and a degradable material capable of undergoing an irreversible degradation downhole.

Abstract: The present invention involves methods and compositions for treating subterranean formations, and more specifically, relates to improved methods and compositions for degrading filter cake deposited in a subterranean formation by effecting a uniform distribution of a filter cake breaker. One embodiment of the present invention provides a weighted encapsulated breaker comprising a breaker material; and, a coating material comprising a polymer material and a filler material having a specific gravity of at least about 6.5.

Abstract: It has been discovered that solid, particulate dicarboxylic acids are useful as diverting agents in methods for acidizing subterranean formations to improve the uniformity of the acid treatments (acid displacement) by diverting acid to intervals of relatively less permeability. Particularly suitable solid, particulate dicarboxylic acids include, but are not necessarily limited to, those insoluble in both aqueous and hydrocarbon liquids, but which are soluble in mutual solvents or alcohol blends. These acids may have melting points of from about 180 to about 300° F. (about 82 to about 149° C.), formula molecular weights of from 146 to 400, and mesh sizes of from about 20 mesh to about 400 mesh (about 841 to about 38 microns). Particular dicarboxylic acids that fit this description include, but are not necessarily limited to, dodecanedioic acid, undecanedioic acid, decanedioic acid, azelaic acid, suberic acid, and mixtures thereof.

Abstract: Xanthan gels hydratable in brine, methods of making these xanthan gels, and methods of using these compositions in subterranean formation applications, such as gravel packing, are provided herein.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: A method for inhibiting hydrate formation in a hydrocarbon flow by adding an amount of a dendrimeric compound effective to inhibit formation of hydrates at conduit temperatures and pressures, and flowing the mixture containing the dendrimeric compound and any hydrates through the conduit. Preferably, a hyperbranched polyester amide is used as hydrate formation inhibitor compound.

Abstract: A method of treating a hydrocarbon-containing formation is disclosed. The method includes injecting a well treating fluid into a well, wherein the well treating fluid includes a self-diverting acid that includes about 1% to 30% by weight of at least one acid selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, citric acid, maleic acid, hydrofluoric acid and mixtures thereof; and about 1% to 20% by volume of at least one viscoelastic surfactant selected from a family of compounds described by where R3 contains at least 10 carbon atoms, p=1-6, R2 contains 1-6 carbon atoms and R1 contains 1-6 carbon atoms; and about 0.7% to 20% by weight scale inhibitor.

Abstract: It has been discovered that solid, particulate dicarboxylic acids are useful as diverting agents in methods for acidizing subterranean formations to improve the uniformity of the acid treatments (acid displacement) by diverting acid to intervals of relatively less permeability. Particularly suitable solid, particulate dicarboxylic acids include, but are not necessarily limited to, those insoluble in both aqueous and hydrocarbon liquids, but which are soluble in mutual solvents or alcohol blends. These acids may have melting points of from about 180 to about 300° F. (about 82 to about 149° C.), formula molecular weights of from 146 to 400, and mesh sizes of from about 20 mesh to about 400 mesh (about 841 to about 38 microns). Particular dicarboxylic acids that fit this description include, but are not necessarily limited to, dodecanedioic acid, undecanedioic acid, decanedioic acid, azelaic acid, suberic acid, and mixtures thereof.

Abstract: An aqueous oilfield treatment fluid containing a chelating agent and an HF source is described. This fluid is effective at dissolving siliceous materials such as clays and keeping the dissolved materials in solution. In particular it is effective at preventing re-precipitation of initially-dissolved silicon as silica and therefore reduces damage to sandstones with which it is contacted. Methods are given for using this fluid for sandstone matrix stimulation, removal of clay-containing drilling fluid components and filter cakes from wellbores, sandstone acid fracturing, and gravel pack and proppant pack cleaning.

Abstract: Improved methods and compositions for consolidating proppant in subterranean fractures are provided. In accordance with the methods of the invention, proppant particles coated with a hardenable bisphenol A-epichlorohydrin resin composition are mixed with a gelled liquid fracturing fluid and the fracturing fluid is pumped into a subterranean zone. The fracturing fluid forms one or more fractures in the subterranean zone and deposits the proppant particles coated with the resin composition therein. Thereafter, the hardenable resin composition on the proppant particles is allowed to harden by heat and consolidate the proppant particles into degradation resistant permeable packs. The hardenable bisphenol A-epichlorohydrin resin compositions of the invention are storable for long periods of time before use.

Abstract: The present invention provides xanthan gels hydratable in brine, methods of making these xanthan gels, and methods of using these compositions in subterranean formation applications, such as gravel packing.

Abstract: An environmentally friendly corrosion inhibiting formulation for the oil-water interface of pipe lines and oil well drilling systems which is prepared pursuant to a process including the steps of reacting an acid selected from the group consisting of a fatty acid anhydride and a 21 carbon dibasic acid with an amine or imidazoline to form a corrosion inhibitor consisting essentially of a fatty acid derivative; dissolving the inhibitor in a fatty acid oil or ester selected from the group consisting of soybean oil or methyl soya ester; adding water dispersing agents consisting of sulfonates and a long chain ethoxylated alcohol; and adjusting the viscosity with an alcohol comprising isopropanol.

Abstract: Zeolite compositions having enhanced compressive strength and methods therefor are provided. In particular, methods and compositions for wellbore treating fluids, especially settable spotting fluids having enhanced compressive strength are provided.

Abstract: A method of electrically logging subterranean wells using a conductive double emulsion fluid includes a miscible combination of an oleaginous fluid, an emulsifier capable of forming a microemulsion, an emulsifier capable of forming an invert emulsion, and an electrolytic salt. A microemulsion is the continuous phase of an invert emulsion. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The fluid may additionally contain a polar organic solvent and a carbon dioxide buffer. 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.

Abstract: The present invention provides improved methods for cementing. The methods are basically comprised of the steps of preparing a cement composition comprised of hydraulic cement, water, gas, surfactants, a cement early strength accelerator and a mildly set retarding cement dispersing agent, placing the cement composition in the annulus between the casing string and the well bore and allowing the cement composition to set into a hard impermeable mass. The cement composition used can alternatively comprise hydraulic cement, a water reducing additive, a dispersing additive, a set accelerating additive and water. Also, the cement composition can be made environmentally benign by using water reducing and dispersing additives, set retarding additives, and compressive strength and set accelerating additives which are environmentally degradable.

Abstract: The current invention provides methods of using and drilling and servicing fluid compositions for depositing and removing filter cake from the walls of a well bore. The compositions make use of particulate solid bridging agent comprised of a salt of an organic acid. The bridging particles are dissolvable by a clean-up solution comprised of a mild solvent that is less corrosive than the conventional strong mineral acids used for this purpose.

Abstract: The present invention relates to a method and a fluid for drilling or intervening in a well passing through a porous, permeable formation, wherein a water-based well fluid is circulating in said well. In this method, there is added to the fluid not only the conventional ingredients for such a fluid but also a maximum of 10 wt. % of a composition obtained from a grease or oil and an alcohol, with the chain lengths of the acid and alcohol parts being chosen such that the ester thus obtained has sufficient dispersion in water, compatibility with said ingredients, does not form an emulsion with the reservoir oil, and adsorbs sufficiently on the porous formation.

Abstract: A method of the preparation and utilization of polymerized alpha-hydroxycarboxylic-acid-coated proppants for gravel pack and removal of filter cake that was deposited by reservoir drilling fluid. In a preferred example, polyglycolic-acid-coated sand is used to replace conventional gravel pack sand typically used for gravel packing. Under downhole conditions, the acidic by-product generated from the hydration of polyglycolic-acid-coated sand can break down acid-soluble and/or acid-breakable components embedded in the filter cake. This reaction enhances the filter cake removal and the flow of hydrocarbon from the producing formation. The polyglycolic-acid-coated sand may be produced by polymerizing a glycolic acid with a natural or synthetic proppant like 20-40 mesh commercial sand, at temperatures of about 210° F. or higher.

Abstract: A method for treating an underground reservoir, which method comprises introducing into the reservoir a treatment fluid comprising, dissolved or dispersed in water, an ester and a non-enzyme catalyst capable of increasing the rate of hydrolysis of the ester, such that the ester hydrolyses to produce an organic acid to dissolve acid soluble material present within the reservoir.

Abstract: Methods of cementing in wellbores using cement compositions having elasticity or high compressive strength and low permeability are provided. The cement compositions are basically comprised of particulate acid degradable glass, water, at least one water soluble polymerizable alkenoic acid monomer and a water soluble free-radical initiator.

Abstract: The present invention provides seawater-based cross-linked fracturing fluids and methods of preparing and using the fluids in fracturing subterranean formations penetrated by well bores and having temperatures above about 200° F. The improved cross-linked fracturing fluids are basically comprised of a gelling agent, seawater present in an amount sufficient to hydrate the gelling agent and to form a gelled aqueous fluid, and a delayed cross-linking agent, capable of causing delayed cross-linking of the gelling agent in the gelled aqueous fluid at a pH below the threshold for precipitate formation in seawater.

Abstract: The present invention provides improved compositions and methods for cementing casing strings in deep water offshore formations penetrated by well bores. The cement composition basically comprises hydraulic cement, water, an environmentally degradable water reducing and dispersing additive, an environmentally degradable set retarding additive and an environmentally degradable compressive strength and set accelerating additive.

Abstract: The present invention provides seawater-based cross-linked fracturing fluids and methods of preparing and using the fluids in fracturing subterranean formations penetrated by well bores and having temperatures above about 200° F. The improved cross-linked fracturing fluids are basically comprised of a gelling agent, seawater present in an amount sufficient to hydrate the gelling agent and to form a gelled aqueous fluid, and a delayed cross-linking agent, capable of causing delayed cross-linking of the gelling agent in the gelled aqueous fluid at a pH below the threshold for precipitate formation in seawater.

Abstract: A one step squeeze treatment of a subterranean formation involves the treatment with a treating solution comprising an acid, a scale inhibitor, and a reducing agent. The presence of the reducing agent prevents the iron ions in the system from reacting with and forming a precipitate with the scale inhibitor and maintains the iron ions in the ferrous state.

Abstract: The present invention relates to a method for inhibiting corrosion of corrosion-prone metal surfaces by organic acid-containing petroleum streams by providing an effective corrosion-inhibiting amount of certain sulfur and phosphorus-free aromatic compounds substituted with nitrogen, containing functional groups at the 5- or 3, 5-position, typically up to 1000 wppm, to the metal surface.

Abstract: It has been discovered that dicarboxylic acids are useful in acidizing subterranean formations to improve their permeability, particularly at elevated temperature, e.g. between about 200° F. (92° C.) and about 400° F.(204° C.) Particularly suitable dicarboxylic acids include, but are not necessarily limited to, succinic acid, glutaric acid, adipic acid, and mixtures thereof.

Abstract: The present invention relates to a method for inhibiting high temperature corrosion of corrosion prone metal surfaces by organic acid-containing petroleum streams by providing an effective corrosion-inhibiting amount of an additive aromatic compound tri-substituted with acidic functionalities selected from 5-hydroxyisophthalic acid and 1,3,5-benzenetricarboxylic acid, typically up to 1000 wppm, to the metal surface.

Abstract: An additive for inhibiting the formation of gas hydrates in connection with hydrocarbon production and transportation comprising the water-soluble polymers comprising structural elements of the formula wherein each R is independently H or C1-C5-alkyl; X is H, an alkaline or earth alkaline metal or a quaternary ammonium group; R1 is H or C1-C18-alkyl; and R2 is C1-C18-alkyl; and wherein the alkyl groups represented by R1 and R2 optionally carry a hydroxy or amino substituent; and, optionally, a minor proportion of structural elements of the formula  wherein R, R1, R2 and X may have the meaning as above, and Alk is a C1-C5-alkylene chain.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: An additive for inhibiting the formation of gas hydrates in connection with hydrocarbon production and transportation comprising the water-soluble polymers comprising structural elements of the formula wherein each R is independently H or C1-C5-alkyl; X is H, an alkaline or earth alkaline metal or a quaternary ammonium group; R1 is H or C1-C18-alkyl; and R2 is C1-C18-alkyl; and wherein the alkyl groups represented by R1 and R2 optionally carry a hydroxy or amino substituent; and, optionally, a minor proportion of structural elements of the formula wherein R, R1, R2 and X may have the meaning as above, and Alk is a C1-C5-alkylene chain.

Abstract: An esterification process and the products resulting from it which achieves a mixture of secondary esters which are effectively used with invert drilling muds, the process involving the addition of one or more C1-C5 carboxylic acids and one or more C3-C22 olefins in the presence of an acid catalyst.

Abstract: The invention relates to a process for facilitating the disposal of flowable and pumpable working fluids based on emulsifiers containing W/O invert emulsions--more particularly corresponding auxiliaries of the type used in geological exploration, such as oil-based w/o invert drilling muds--and for the simplified cleaning of solid surfaces soiled therewith, if desired using flowable spraying aids, the process being characterized in that, by selecting and adapting the emulsifiers/emulsifier systems to the oil phase of the invert emulsion, temperature-controlled phase inversion is achieved at temperatures below the in-use temperatures of the w/o invert emulsions, but above the freezing point of the aqueous phase and in that disposal and cleaning are carried out at temperatures in and/or below the phase inversion temperature range.

Abstract: An esterification process and the products resulting from it which achieves a mixture of secondary esters which are effectively used with invert drilling muds, the process involving the addition of one or more C.sub.1 -C.sub.5 carboxylic acids and one or more C.sub.3 -C.sub.22 olefins in the presence of an acid catalyst.

Abstract: The invention relates to flowable and pumpable multicomponent mixtures based on a multiphase mixture of water and oil containing emulsifiers and, if desired, other soluble, emulsifiable and/or dispersible auxiliaries for their use in exploration by drilling and/or for the further treatment of the wells thus drilled. The invention is characterized by the use of emulsifiers or emulsifier systems which, in the particular multicomponent mixture in question, lead to temperature-controlled phase inversion at a phase inversion temperature (PIT) in a temperature range of which the upper limit is so far below the working temperature of the multicomponent mixture in geological exploration that the water-based part of the multicomponent mixture is present as a disperse (invert) phase in the continuous oil phase (w/o invert emulsion) while the lower limit of this temperature range enables the multicomponent mixture to be converted into an o/w emulsion with a continuous aqueous phase.

Abstract: 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.

Abstract: Corrosion is inhibited in hydrochloric acid solutions used to acidize wells, by adding to the solutions a corrosion inhibiting composition comprising cinnamaldehyde or a substituted cinnamaldehyde together with a reaction product of a C.sub.3-6 ketone such as acetophenone, thiourea or a related compound, formaldehyde and hydrochloric acid.

Abstract: A gelling composition comprises a multivalent metal compound-crosslinkable polymer such as a carboxylate-containing polymer, a multivalent metal compound such as a zirconium compound, a liquid, and a pH-lowering agent such as carbon dioxide wherein the composition is prepared by combining the polymer and multivalent metal compound to form a mixture and, thereafter, introducing carbon dioxide to the mixture. A process for treating a subterranean formation can comprise the steps of: (1) combining a polymer with a multivalent compound to form a mixture; (2) introducing the another mixture into a subterranean formation; and (3) introducing carbon dioxide into the mixture.

Abstract: A process for altering the permeability of a subterranean formation comprises injecting into the subterranean formation a gelling composition which comprises a carboxylate-containing polymer, a crosslinking agent, and a liquid such as a produced brine wherein the polymer forms a gel in the formation, in the presence of the crosslinking agent. The polymer can have a molecular weight of from about 10,000 to about 30,000,000, contain about 0.01 to about 10 mole % of a carboxylate group, and be present in the gelling composition in the range of from about 100 to about 100,000 mg per liter of the composition.

Abstract: The present invention provides improved quaternary ammonium compounds useful as metal corrosion inhibitors in aqueous acid solutions, methods of preparing the compounds, metal corrosion inhibited aqueous acid solutions containing the compounds and methods of protecting metal surfaces from acid corrosion using the compounds. The compounds are prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen to oligomerize aromatic amines contained therein and then reacting the oligomerized amines with a benzylhalide.

Abstract: An improved method for acidizing an oil bearing formation in the presence of water bearing zones having high permeability is described. An aqueous fluid is pumped into the formation preceding the injection of stimulation material. This fluid contains hydroxyethylcellulose, a fluorescent dye and an organic acid anhydride, which during hydrolysis reduces the pH and the viscosity of the solution making it retrievable without damage to the formation.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a defined class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of selected orthophosphate esters and ferric ammonium citrate or lower alkyl amine derivative thereof. The lower alkyl amine derivatives are referred to as ferric alkylamine citrates.

Abstract: A composition and method for use in freeing differentially stuck pipes is presented, comprising a hydrocarbon, acetic acid and a surfactant. The composition frees stock pipes quickly, thus reducing down-time during the process of drilling a subterranean well.

Abstract: A concentrate for use with an oil or water carrier for injection into a well to enhance production and a method of well treatment are disclosed. The five part concentrate contains xylene, an aliphatic hydrocarbon solvent such as kerosene, a non-ionic emulsifier, a non-ionic surfactant and an amphoteric detergent. The xylene and kerosene create a solvent hole in the materials restricting flow. The surfactant expands the holes while the detergent and emulsifier assist in dispersing the removed material to thereby stimulate production from the well. The injection of the concentrate and carrier mixture can take place during shut-in of the well or during continued production.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a define class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of (1) selected orthophosphate esters and (2) a composition comprising a source of ferric ions, an amine, and a polycarboxylic acid or salt thereof.

Abstract: This invention relates to a composition comprising: a mixture of a brine and a liquid oil, and (A) an emulsifying amount of (i) at least one reaction product of a hydrocarbyl-substituted succinic acylating agent, and at least one of (a) ammonia, (b) an alcohol, (c) an amine, (d) or mixtures thereof, or at least one salt of the reaction product; or (ii) at least one reaction product of a hydroxyaromatic compound, an aldehyde, and an amine. The compositions of the present invention have beneficial emulsification properties. These compositions are useful in drilling, working over and completing well-bore holes. The well-drilling compositions of the present invention have beneficial viscosity, pumping and suspension properties.

Abstract: An aqueous fracturing fluid composition and method for fracturing subterranean formations penetrated by a well bore wherein the fracturing fluid comprises a viscosity breaker that comprises a surfactant and a breaker which is solid at ambient surface conditions and dissolves at temperatures in the formation.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a define class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of selected orthophosphate esters and ferric ammonium citrate or lower alkyl amine derivative thereof. The lower alkyl amine derivatives are referred to as ferric alkylamine citrates.

Abstract: A composition, especially suitable for use as a mud sweep and a spacer. The composition includes a petroleum-based hydrocarbon, a biopolymer, a thickening agent, a surfactant and potassium chloride. Other optional ingredients in embodiments of the present invention include a lower alkanol, sodium salts and aluminum stearate.

Abstract: A gelling composition and a process for wellbore treatment comprising injecting the composition into reservoirs are disclosed wherein the composition comprise a produced brine; a water-soluble polymer such as, for example, polyacrylamide; a crosslinker such as, for example, a complexed zirconium compound; and optionally a complexing ligand such as, for example, lactic acid.