Abstract: For well kill treatment to prevent the intrusion of formation fluids into the wellbore while the well is open, a well kill additive including a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, filter aid, and optionally, a reinforcing material of fibers and/or comminuted plant materials. The method of forming a well kill fluid includes contacting the additive with water or an aqueous solution, with a method of conforming the formation further including the step of injecting the fluid into the wellbore.

Abstract: Methods of using invertible oil external-water internal emulsions in drilling, hydraulic fracturing, gravel packing and completion and then inverting the emulsion to a water external-oil internal emulsion are provided. The methods basically comprise the steps of contacting the oil external-water internal emulsion with an aqueous acid solution containing an anionic sulfonate surfactant for preventing aqueous acid solution-crude oil emulsions and crude oil sludging and a chemical for preventing the anionic sulfonate surfactant from reacting with the emulsifier in the oil external-water internal emulsion.

Abstract: For tubing/casing annulus plug treatment to plug a well, a tubing/casing annulus plug additive including a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, a filter aid, and an optional reinforcing material, preferably of fibers and/or comminuted plant materials. The method of forming a tubing/casing annulus plug fluid includes contacting the additive with water or an aqueous solution, with a method of plugging the tubing/casing annulus of a well further including the step of injecting the fluid into the annulus.

Abstract: The invention provides a method of treating of a well, a formation, or both, with the solids, liquids, or apparatuses, by 1) encasing said solids, liquids, or apparatuses in a water-soluble shell, 2) conveying said encased solids, liquids, or apparatuses to a predetermined location in the well, and then 3) allowing the water-soluble shell to dissolve in the aqueous phase in the wellbore. The shell is preferably made of water-soluble polyvinyl alcohol copolymers and a waterproofing agent. The shell encases a variety of solids, liquids, or combinations thereof, where said solids or liquids are useful in the treatment of the well or of the producing formation. Illustrative encased material includes soap, acid, corrosion inhibitors, chelating agents, scale inhibitors, mutual solvents, paraffin inhibitors, paraffin dissolvers, clay stabilizers, and tracer materials. The encased materials may also be apparatuses, such as a prefabricated screen completion or a prefabricated sand-pack.

Abstract: A temperature-stable, non eco-toxic oil-base well fluid that is particularly suitable for high pressure/high temperature drilling comprises an emulsification system comprising at least one superamide that may or may not be polyalkoxylated, optionally associated with a non-ionic co-surfactant. The oil-base well fluid comprising such a system can be used at temperatures of up to about 200° C. due to the production of highly temperature-stable reverse emulsions.

Abstract: Improved methods of preventing the flow-back of particulates deposited in subterranean formations with produced formation fluids are provided. The methods include extruding or injecting a solution or mixture of a particulate solid polymer through a plurality of small diameter ports into an aqueous carrier fluid containing suspended particulate material whereby polymer fibers and strands are formed in the carrier fluid. The polymer fibers and strands mix with the particulate material suspended in the carrier fluid as the carrier fluid is pumped into the subterranean formation. The mixture of the particulate material and the polymer fibers and strands is deposited in the subterranean formation so that the mixture forms at least one permeable pack that prevents the production of formation fines with fluids produced from the formation and prevents the flow-back of the deposited particulate solids, fibers or strands.

Abstract: Embodiments of the Present Invention relate to a reversibly thickenable non-polymeric fluid that has low viscosity in strong acid, gels when the acid concentration is reduced by only a small amount, and is subsequently decomposed by the acid. In particular it relates to an aqueous mixture of zwitterionic surfactants, inorganic acids, and organic acids Most particularly it relates to the use of this fluid as a diverting agent for easily-damaged sandstones, for example prior to matrix acidizing.

Abstract: Disclosed is a process for preparation of compositions having utility as well fluid base oils. The process involves metathesis of alpha-olefins followed by isomerization of the metathesis products. The base oils resulting from the process of this invention are environmentally friendly in that they are only mildly toxic to marine life, are highly biodegradable and have very low pour point temperatures. These properties make the base oils ideal candidates for use as components of well fluids for cold climates and offshore applications.

Abstract: A viscous aqueous high density well treatment fluid composition stable at high temperature containing a surfactant and inorganic salts is described. Methods of preparing the fluid and increasing the stability and viscosity of the fluid are given. The fluid is useful for wellbore cleanout, hydraulic fracturing, gravel packing, completion, acid diversion, lost circulation reduction, well killing, cementing, selective water shutoff, and fracture fluid diversion.

Abstract: Disclosed is a process for preparation of compositions having utility as well fluid base oils. The process involves metathesis of alpha-olefins followed by isomerization of the metathesis products. The base oils resulting from the process of this invention are environmentally friendly in that they are only mildly toxic to marine life and have very low pour point temperatures. These properties make the base oils ideal candidates for use as components of well fluids for cold climates and offshore applications.

Abstract: A method and sealing composition is provided for sealing a subterranean zone penetrated by a well bore, wherein the sealing composition comprises a mixture of cementitious material, cross-linkable material, and sufficient water to form a slurry.

Abstract: A method of treating a well including injecting a well-treating fluid into the well, where the well-treating fluid comprises a glycol compound and an organic liquid, the glycol compound and organic liquid being present in amounts selected to achieve a desired density. In another embodiment, a well fluid including a glycol compound an organic liquid, and a salt, wherein the glycol compound, organic liquid, and salt are present in amounts selected to achieve a predetermined density is disclosed.

Abstract: A non-aqueous suspension including boron-containing particulates, a low molecular weight polyalkylene glycol and a suspension stabilizer is provided. Methods of crosslinking water soluble polymers and of fracturing a subterranean formation are also provided.

Abstract: The present invention provides the use of surface-modified nanoparticles in fluids used to recover hydrocarbon from underground formations. The use of surface-modified nanoparticles in such fluids provides foams that are stable under pressure yet have a shorter foam lifetime than typical surfactant-stabilized foams after the pressure is released or lowered.

Abstract: The Invention relates to novel fluids and techniques to optimize/enhance the production of hydrocarbon from subterranean formations (e.g., “completion fluids”), in particular, fluids and techniques are disclosed and claimed which remove wellbore damage and near-wellbore damage in the form of coating formed from drilling and production-related operations (“filtercake”); the techniques can be applied either by themselves or in conjunction with other completion operations, such as gravel packing; preferred embodiments are chelating agent and enzyme systems in a viscoelastic surfactant (VES) matrix.

Abstract: A new stable liquid suspension containing non-soluble particles dispersed in a non-aqueous liquid medium having a concentration of a suspension aid and a method of making and use thereof.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air.

Abstract: A method of controlling the pressure of a casing annulus in a subterranean well that includes injecting into the casing annulus a composition including a base fluid and a polymer coated colloidal solid material. The polymer coated colloidal solid material includes: a solid particle having an weight average particle diameter (d50) of less than two microns, and a polymeric dispersing agent coated onto the surface of the solid particle during the cominution (i.e. grinding) process utilized to make the colloidal particles. The polymeric dispersing agent may be a water soluble polymer having a molecular weight of at least 2000 Daltons. The solid particulate material may be selected from materials having of specific gravity of at least 2.

Abstract: Compositions and methods for treating systems, especially oil and/or gas wells, characterized by metal sulfide deposits are provided. Compositions according to the invention generally comprise a thioacid, an amine salt, and a diphosphonic acid. Methods according to the invention may comprise introducing such composition into a system characterized by metal sulfide deposits, or alternatively, introducing into the system individual quantities of the composition components.

Abstract: According to the invention, a method of treating a subterranean formation is provided comprising the steps of: (a) forming a mixture comprising: (i) a particulate, (ii) an elastomer-forming component in a liquid form or in a solvent solution, and (iii) a fluid for carrying the particulate through the well into the subterranean formation; and (b) introducing the mixture into the subterranean formation. The elastomer-forming component has the following characteristics under laboratory testing: (a) the component, by itself or with a curing agent, is capable of being cured to form an elastomeric material, and (b) the component, at a test level of 2 percent by weight over the particulate alone and under conditions of sufficient stress loading, is capable of forming the particulate into a flexible and coherent mass.

Abstract: A method and composition is provided for sealing a subterranean zone penetrated by a well bore to restore lost circulation. In one embodiment, the composition comprises a pellet comprising a mixture of lost circulation materials (LCMs).

Abstract: Disclosed is a microemulsion well treatment microemulsion that is formed by combining a solvent-surfactant blend with a carrier fluid. In preferred embodiments, the solvent-surfactant blend includes a surfactant and a solvent selected from the group consisting of terpenes and alkyl or aryl esters of short chain alcohols. The disclosed well treatment microemulsion can be used in well remediation, stimulation and hydrogen sulfide mitigation operations. Additionally, the well treatment microemulsion can be used in the production of benzothiophenes through interaction with hydrogen sulfide.

Abstract: A fluid-loss pill that includes a brine solution and an effective amount of a viscoelastic surfactant is disclosed.

Abstract: The effect of various chemical or biological agents in well treatment fluids can be delayed by sequestering the agents in the discontinuous phase of an emulsion for a period of time, before the emulsion is destabilized by exposure to at least one of: (1) a change in temperature, (2) a change in pH, (3) a change in salinity, (4) a change in alcohol concentration, (5) a change in stabilizing surfactant concentration, (6) a change in organic ion concentration, (7) a change in destabilizing surfactant concentration, (8) a change in surfactant adsorbent material concentration, (9) an ultrasonic pulse, and (10) an electrical field. Upon exposure to the emulsion destabilizing condition, the agent sequestered in the discontinuous phase of the emulsion is released into the continuous phase of the fluid composition, where it can have its intended effect.

Abstract: A fluid having utility in subterranean wells is formulated to include: an oleaginous fluid; and a solids tolerance agent having the formula: 1

Abstract: An improved lightweight and highly permeable proppant composition for use in increasing the productivity of a gas or oil well. The proppant composition includes equal amounts by weight of uncalcined bauxite, uncalcined shale and quartz, held together with a binder formed of wollastonite and talc in an amount of less than 10% by weight of the composition. The proppant composition has an alumina content of less than 25% by weight of the composition and a silica content of over 45% by weight of the composition.

Abstract: An oil shale formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. A reducing environment may be maintained within a portion of the formation.

Abstract: Disclosed is a concentrate composition for crosslinking polysaccharide polymers hydrated in an aqueous liquid, and well servicing fluids, preferably fracturing fluids, prepared therewith. Preferred polysaccharide polymers are galactomannan gums or derivatives thereof, preferably hydroxypropylguar. The concentrate comprises an alkali metal formate solution, preferably potassium formate, a crosslinking agent for the polysaccharide polymer, preferably a sparingly soluble alkali metal or alkali metal alkaline earth metal borate, and a suspension agent, preferably a clay mineral selected from the group consisting of smectite clays, palygorskite clays, and mixtures thereof Exemplary clays are hectorite, sepiolite, and attapulgite. The concentrate may, optionally, contain a deflocculant and/or an anti-syneresis additive.

Abstract: A solids-stabilized oil-in-water emulsion and a method for preparing the solids-stabilized oil-in-water emulsion. The oil-in-water emulsion is formed by combining oil, water, solid particles and a pH enhancing agent and mixing until the solid-stabilized oil-in-water emulsion is formed. The low viscosity oil-in-water emulsion can be used to enhance production of oil from subterranean reservoirs. The low viscosity oil-in-water emulsion can also be used to enhance the transportation of oil through a pipeline.

Abstract: A method is provided for diverting the majority of the fluid injected into a stratified subterranean formation, that has at least one problematic zone and at least one hydrocarbon zone, into the hydrocarbon zone. In the method, a viscous diverting fluid made with a gelling amount of a surfactant and an acid is injected before the main treatment; after the treatment the acid decomposes the surfactant. The main treatment may be hydraulic fracturing, acid fracturing and matrix acidizing. The fluid used as the diverting fluid may also be used as the carrier fluid in hydraulic fracturing or gravel packing. Destruction of the surfactant alleviates the potential of diverters or carrier fluids to damage formations.

Abstract: It was found that the addition of polymers to viscoelastic surfactant base system allows to adjust the rheological properties of the base fluid.

Abstract: A method for treating a relatively low permeability formation containing heavy hydrocarbons in situ may include providing heat from one or more heat sources to a portion of the formation. The heat may be allowed to transfer from the heat sources to a selected section of the formation. The transferred heat may pyrolyze at least some hydrocarbons within the selected section. A mixture of hydrocarbons may be produced from the selected section. In certain embodiments, one or more heat sources may be placed in an uncased wellbore.

Abstract: A composition comprising a water-in-oil emulsion fluid for use in the drilling, completion or workover of a subterranean well is disclosed, wherein the emulsion fluid comprises:

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of vanadium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation.

Abstract: An additive which increases the density of wellbore fluids used during the construction or repair of oil, gas, injection, water or geothermal wells comprises solid colloidal particles of weight average particle diameter (D50) of less than 2 microns, the particles being deflocculated by the action of a dispersant, preferably incorporated during the process of grinding or communication of the particles to the specified particle size. The additives may be used in any wellbore fluid such as drilling, cementing, completion, packing, work-over (repairing), stimulation, well killing and spacer fluids as well as in a dense media separating fluid or in a ship's ballast fluid.

Abstract: This Invention relates to methods of treating a subterranean hydrocarbons reservoir comprising contacting the formation with a treating fluid comprising an aqueous solution, an acid, a surfactant acting as gelling agent essentially consisting of erucylamidopropyl betaine (or a protonated/deprotonated homolog or salt thereof). The treating fluid may further comprise a lower n-alcohol for improved temperature stability.

Abstract: Anti-corrosion additives and processes useful for oil drilling and similar applications. Heteropoly complex anions of transitional metal elements can be added to an oil well drilling solution which includes a metallic salt, optionally in combination with transition metal compounds or compounds of the metallic elements of Groups IIIa to VIa of the Periodic Table of Elements, to minimize corrosion of systems within which the solution is used.

Abstract: Water soluble associative polymers and compositions comprising them together with alkali metal salts of carboxylic acid are disclosed. Methods comprise introducing into a wellbore a fluid comprising such associative polymers and alkali metal salts of carboxylic acid, e.g., cesium formate. Disclosed water soluble associative polymers have functionality including at least sulfonate groups, carboxylate groups and hydrophobes associative with one another in a saturated aqueous solution of an alkali metal salt of a carboxylic acid.

Abstract: Fluids, such as completion fluids, containing at least one alkali metal tungstate and optionally at least one chelating agent are described. Methods of removing a filter cake from a well bore surface, which may include one or more alkaline earth metal sulfates, is also described, wherein the method includes contacting the filter cake with the completion fluid of the present invention. A drilling fluid or mud is also described wherein the drilling fluid contains at least one alkali metal tungstate. The drilling fluid preferably further contains at least one emulsifier or surfactant and at least one hydrocarbon-based fluid. The various fluids of the present invention can contain other conventional ingredients and optionally at least one alkali metal formate. The present invention permits the fluids to be essentially solids free due to the use of the alkali metal tungstate.

Abstract: A process for treating a hydrocarbon-bearing formation having at least one hydrocarbon bearing zone and at least one water bearing zone wherein the ratio of the permeability of the hydrocarbon bearing zone(s) to the permeability of the water bearing zone(s) is in the range of from 1:20 to 3:1 comprising: a) sequentially injecting into the formation: (i) an aqueous polymer solution comprising 0.01 to 0.5 weight percent of a water-soluble polymer having from 0.01 to 7.5 mole % of crosslinkable carboxylate and/or phosphonate groups and a molecular weight in the range of 250,000 to 12,000,000; and (ii) an aqueous solution of a crosslinking agent; and b) back-producing the aqueous polymer solution over the crosslinking agent so that the polymer crosslinks within the formation to form a gel which is collapsible to allow hydrocarbon flow.

Abstract: Treating compositions containing mutual solvents suitable for forming and maintaining single-phase aqueous fluid treating compositions containing very high concentrations of acids and/or chelating agents are described. Methods of use of these treating compositions for dissolving and removing scale and formation matrix material in oil-field treatments such as stimulation and remediation are given.

Abstract: To overcome obstacles faced by current remediation technologies for contaminated sediments, the present invention provides a new strategy based on in situ control of hydrophobic organic contaminants (HOC) bioavailability. The strategy employs the addition to sediments of coal- and wood-derived carbon sorbents, so-called black carbon particles such as activated carbon, char, charcoal, coal, and coke. These black carbon materials sorb HOC contaminants strongly and reduce release of HOCs into water, and reduce HOC uptake by benthic biota, thereby reducing environmental exposure and human health risk to such contaminants. By in situ sorbing the contaminants, the inventive approach reduces environmental exposure and avoids massive material removal while controlling food web transfer of HOCs including polychlorinated biphenyls (PCBs).

Abstract: It has been discovered that fracturing fluid compositions can be designed for successful deep water completion fracturing fluid operations. These fluids must be pumped relatively long distances from offshore platforms to the reservoir, and they are often subjected to a wide temperature range. Under these conditions, it is necessary to inhibit the formation of gas hydrates in the fracturing fluid compositions, as well as to delay the crosslinking of the gels that are formed to increase the viscosity of the fluids prior to fracturing the formation. Preferably, two different gas hydrate inhibitors are used to ensure placement of a gas hydrate inhibitor in most parts of the operation. In addition, as with all offshore or deep water hydrocarbon recovery operations, it is important that the components of the fracturing fluid compositions be environmentally benign and/or biodegradable.

Abstract: It has been discovered that borate crosslinked fracturing fluid breaker mechanisms are improved by the inclusion of a cation-releasing material. When cations are released or liberated within the fracturing fluid, they complex with the hydroxide or carbonate pH buffers used within the borate crosslinked fracturing fluid, which in turn reduces the pH of the fracturing fluid. Once the pH is lowered, viscosity reduction (breaking) occurs by uncrosslinking of the polymer within the fracturing fluid, and by initiating or increasing activity of an enzyme breaker, if present. In one embodiment, the cations are divalent cations. The divalent cations are preferably slowly released over a period of time. Two specific, preferred materials for releasing divalent cations are calcium lignosulfonate and calcium chloride, the latter preferably in encapsulated form.

Abstract: The present invention provides methods of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The methods are basically comprised of introducing into the subterranean zone an aqueous well treating fluid comprised of water and a water soluble polymer complex fluid loss control additive.

Abstract: A method of treating a subterranean formation, the method comprising: (A) injecting down a well bore into the formation an admixture of (a) an emulsion having an internal aqueous phase comprising a water-soluble oil or gas field chemical or an aqueous dispersion of a water-dispersible oil or gas field chemical and an external oil phase comprising a liquid hydrocarbon and an oil-soluble surfactant and (b) a demulsifier comprising a solution of a surfactant having a cloud point temperature of above 40 ° C.; or (B) separately injecting down a well bore into the formation emulsion (a) and demulsifier (b) and generating an admixture of emulsion (a) and demulsifier (b) within the formation.

Abstract: A method for treating groundwater and soil with a chemical oxidant, such as potassium permanganate, is provided. A chemical is placed in a powdered or pellet form into injection wells. Baffles are inserted into the ground to direct groundwater flow toward the injection wells. The groundwater flows through the injection wells to pick up the chemical oxidant. A second set of baffles are placed between the injection wells and the contaminated zone to disperse the chemical oxidant laden water. The chemical oxidant laden water flows through the contaminated field, the oxidant acting on the contaminated soil and groundwater to treat same. The injection wells can be pressurized to increase groundwater flow. Tests can be conducted on the other side of the contaminated field to measure the effectiveness of the treatment.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a strong mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of rhenium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation. The particular electron transfer agents used in connection with the invention function with virtually all known electron donor agents.

Abstract: Hydraulic fracturing of wells by injecting a degradable polymer phase as a fracturing fluid is provided. Composition and degree of polymerization of the degradable polymer and the selection of additives may be varied to adjust the viscosity, degradation time and other properties of the fracturing fluid. Viscous degradable fluid or pellets of degradable polymer may be placed in a wellbore as an internal phase in a low viscosity carrier fluid. A polymer-continuous liquid phase may be formed at a selected location in the wellbore, usually near perforations, before the polymer phase is pressured into a formation to form a hydraulic fracture.

Abstract: Stimulation, particularly fracturing or acidising, of hydrocarbon wells having bores leading to hydrocarbon bearing uses a fluid including a continuous phase of or including a compound of the formula (I): (R2)p—Ph—(CH2)m—COO—(AO)n—R1 where R1, AO, n, m, Ph, R2 and p have defined meanings and particularly where the esters are alkyl or alkenyl benzoate esters. These esters are beneficial by having a range of viscosities, especially extending to low viscosities. and attractive toxicological and environmental profiles for use in well stimulation.