Abstract: Methods and compositions relating to fluid loss control operations are provided. More particularly, fluid loss treatment fluid compositions may comprise ceramic particulate bridging agents, a partially depolymerized starch derivative, and a base fluid. In some embodiments, the partially depolymerized starch derivative may include a crosslinked ether derivative of a partially depolymerized starch, a partially depolymerized crosslinked ether derivative of a starch, or a combination thereof.

Abstract: The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and citric acid in an amount sufficient to increase the low shear rate viscosity of the fluids. The invention further provides a method of increasing the low shear rate viscosity of fluids which contain a water soluble polymer and a calcined magnesia bridging agent which has an Activity Index greater than about 800 seconds.

Abstract: Provided herein are settable spotting compositions that comprise cement kiln dust and associated methods of use. Also provided are methods that comprise providing a settable spotting composition comprising cement kiln dust; introducing the settable spotting composition into a well bore that penetrates the subterranean formation so as to displace at least a portion of a second fluid from the well bore.

Abstract: A material and a device for releasing chemicals in a fluid environment is disclosed, and a method for releasing substances into downhole fluid environments. The invention also relates to materials for sand control and hydraulic fracturing. The substance release device typically comprises a polymeric material for releasing a substance into a downhole fluid environment in a well, and in preferred embodiments the material comprises a spherical, plastic chemical release capsule which is hard, permeable and may encapsulate a range of solids and/or liquids for subsequent release. These solids or liquids can include inhibitors such as scale inhibitors and other oilfield production chemicals for release into the wellbore of an oil or gas producing well or a water injection well.

Abstract: The present invention relates to methods and compositions for degrading filter cakes in subterranean formations, and more specifically, to improved methods and compositions for degrading filter cakes that comprise acid-soluble portions and polymeric portions.

Abstract: A method of cementing in a subterranean formation that comprises providing a foamed cement composition that comprises water, a cement, a gas, and an additive, the additive comprising an anionic foaming agent and at least one of an anionic foam stabilizer or a Zwitterionic foam booster; placing the cement composition into the subterranean formation; and allowing the cement composition to set therein is provided. Foamed cement compositions, additives for foaming and stabilizing a cement composition, and methods of reducing the density of a cement composition, also are provided.

Abstract: In one embodiment, the present invention provides a method of reducing the viscosity of a viscosified treatment fluid comprising contacting the viscosified treatment fluid with an acid generated from an orthoester composition that comprises an orthoester. In another embodiment, the present invention provides a method of reducing the pH of a viscosified treatment fluid comprising providing an orthoester composition that comprises an orthoester; contacting the viscosified treatment fluid with the orthoester composition; allowing the orthoester to generate a generated acid; and allowing the generated acid to at least partially reduce the pH of the viscosified treatment fluid. Embodiments of fracturing and gravel packing methods also are disclosed.

Abstract: Small spheres, commonly referred to as proppants, are manufactured from sol-gel ceramics, preferably aluminosilicates or phosphates, and include chemical composites termed geopolymers. In the preferred manufacturing process, the required chemical components are blended, and the proppant particles are shaped and cured at low temperatures. The proppant particles have high compressive strength, are chemically inert, and a low specific gravity, making them particularly suited for hydraulic fracturing.

Abstract: The present invention relates to well bore operations, and more particularly, to contained micro-particles, and methods for using such contained micro-particles in cementing operations. An exemplary method of facilitating the use of micro-particles in a well bore fluid comprises the steps of providing contained micro-particles, and adding the contained micro-particles to the well bore fluid. In an exemplary embodiment, the well bore fluids of the present invention comprise encapsulated micro-particles. In another exemplary embodiment, the well bore fluids of the present invention comprise pelletized micro-particles.

Abstract: Methods and compositions for wellbore treating fluids, especially settable spotting fluids, that include zeolite and at least one carrier fluid.

Abstract: Cement compositions including environmentally compatible defoamers and methods of using such cement compositions are provided herein. An example of a method is a method of cementing in a subterranean formation. Another example of a method is a method of reducing foam generation in a cement composition. An example of a composition is a cement composition including water, hydraulic cement, and a defoamer. Another example of a composition is a defoamer.

Abstract: Methods and compositions for wellbore treating fluids, especially remedial compositions such as pills, that include zeolite and at least one carrier fluid.

Abstract: Methods for cementing in a subterranean zone, which use a cement composition that includes zeolite, cementitious material, proportioned fluid loss control additives and a mixing fluid. Cement compositions containing proportioned fluid loss control additives, and methods of making cement compositions containing proportioned fluid loss control additives.

Abstract: Disclosed is a method for introducing additives into an oil, gas, or water injection well or pipeline in solid form at a location other than at the bottom. The method is practiced using pellets having a density sufficient to suspend the pellet at a top phase, bottom phase or at the interface of two phases of fluid within a wellbore. The pellets are prepared from a pellet matrix, such as an ethoxylated wax, and a weighting agent as well as an additive. By varying the amount of weighting agent, the density of the pellet can be varied to suspend it at a desired point to for a time sufficient to deliver the additive to the desired point within the wellbore.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with invert emulsions. The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced.

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 process for stimulating a formation is disclosed wherein a diverting fluid is used to divert an acid treatment package from a high permeability or damaged portion of a formation to a low permeability or undamaged portion of a formation. The fluid, which preferably forms vesicles, comprises at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent.

Abstract: The present invention relates to improved well fluids that include hollow particles, and to methods of using such improved well fluids in subterranean cementing operations. The present invention provides methods of cementing, methods of reducing annular pressure, and well fluid compositions. While the compositions and methods of the present invention are useful in a variety of subterranean applications, they may be particularly useful in deepwater offshore cementing operations.

Abstract: In one embodiment, this invention presents a foaming additive that comprises at least one amidopropyl betaine having the formula: R—CONHCH2CH2CH2N+(CH3)2CH2COO? wherein R is a capryloyl, a capryl, an octyl, a decyl, a cococyl radical, or a mixture thereof. This foaming additive may be utilized in foamed treatment fluids, and those foamed treatment fluids may be utilized in fracturing and sand control treatments in subterranean operations. Associated methods also are presented herein.

Abstract: Methods and compositions for reducing the permeabilities of subterranean formations or zones are provided. The methods of the invention are basically comprised of introducing an aqueous composition into the formation or zone comprised of water, a water soluble organic polymer, an organic gelling agent for cross-linking the organic polymer and a gel retarder comprised of a chemical compound that hydrolyzes or thermolyzes to produce one or more acids in the composition and then allowing the aqueous composition to form a cross-linked gel in the formation or zone.

Abstract: The present invention relates to substantially hydrated cement particulates. More particularly, the present invention relates to compositions comprising substantially hydrated cement particulates and associated methods of use in drilling and subterranean applications. These substantially hydrated cement particulates may be included in drilling and subterranean treatment fluids, inter alia, as carrier particles for admixtures, lost circulation materials, density-varying additives, proppants, and the like.

Abstract: The present invention provides compositions of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The invention includes aqueous well treating fluids comprised of water and a water soluble polymer complex fluid loss control additive. Preferred polymer complexes comprise water-soluble polymers made in the presence of hydroxyethylcellulose.

Abstract: Disclosed are methods of treating subterranean formations by first providing a suspension of colloidal particles prior to the injection of viscoelastic based treatment fluid, and injecting the treatment fluid into a well. The colloidal particles reduce fluid loss into the formation. According to a second embodiment, the treating fluid includes a hydrophobically-modified polymer, said hydrophobically-modified polymer being present at a concentration between approximately its overlap concentration c* and approximately its entanglement concentration ce. The method is particularly useful for fracturing operations in medium to high permeability formations.

Abstract: A method of formulating and the resulting biodegradable wellbore fluid includes a first synthetic internal olefin fraction having from 16 to 18 carbon atoms (C16-18 IO), a second synthetic internal olefin fraction having between 15 to 18 carbon atoms (C15-18 IO), and a third synthetic internal olefin fraction having 15 to 16 carbon atoms (C15-16 IO). The components of the wellbore fluid are blended such that the desired characteristics of polycyclic aromatic hydrocarbon content, toxicity and biodegrability are balance to achieve compliance with environmental requirements for hydrocarbon based drilling fluids.

Abstract: Cement compositions comprising an improved fluid loss control additive, and methods for cementing using such cement compositions, are provided herein. Exemplary embodiments of the cement compositions comprise a hydraulic cement, water, and a fluid loss control additive comprising an acrylamide copolymer derivative, a dispersant, and a hydratable polymer. Optionally, other additives suitable for inclusion in cement compositions may be added.

Abstract: Methods are presented to induce a screenout during a subterranean formation fracturing or combined fracturing and gravel packing treatment having a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting proppant slurry, and causing hydrolysis and dissolution of the solid base-soluble material by adding base so that leak-off increases, the concentration of proppant in the fracture increases, and the proppant screens out. A method of gravel packing with a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting gravel, and causing hydrolysis and dissolution of the solid base-soluble material by adding base. Methods of slowing or accelerating the hydrolysis and dissolution are given, and addition of bridging-promoting materials is included.

Abstract: A cement slurry comprising a base for reducing the impact of an alkaline solution may be displaced into a wellbore and allowed to set. The base may comprise a metal carbonate that is soluble in water such as potassium carbonate. The cement slurry may further include cement, water, and a salt that is soluble in the water such as potassium chloride. The alkaline solution may be present in a formate-based drilling fluid displaced into the wellbore ahead of the cement slurry. Despite being contacted by such an alkaline solution, the thickening time of the cement slurry is long enough and the set time is short enough to provide for the formation of an impermeable mass in the annulus of the wellbore. The thickening times may range from about 4 hours to about 16 hours, and the set times may be less than about 24 hours.

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: Compositions for controlling wellbore fluid and gas invasion including methods for using the compositions. The compositions are initially flowable slurries preferably comprising about 70 to 30% by weight of magnesium oxychloride and about 70 to 30% by weight of water. The compositions undergo a rapid phase transition to form a substantially solid mass with a near-linear relationship between the time required for the phase transition to occur and the composition temperature at which the phase transition occurs thereby permitting accurate determination of the set time. The method includes use of the composition to control the loss of fluids and gases from the wellbore.

Abstract: The present invention relates to methods of stimulating a subterranean formation. More particularly, but not by way of limitation, the present invention relates to methods of fracturing subterranean formations utilizing a fracturing fluid comprising a permeable cement composition that may be used as a propping agent. One method of stimulating a subterranean formation of the present invention comprises the following steps: preparing a permeable cement composition comprising a hydraulic cement, water, and a degradable material capable of undergoing an irreversible degradation downhole; injecting the permeable cement composition into the subterranean formation at a pressure sufficient to create a fracture in the subterranean formation; and allowing the permeable cement composition to form a proppant matrix having voids in the fracture.

Abstract: The current invention provides improved methods and compositions for completing a well bore. In one aspect, the current invention provides a process for preparing a foamed well composition. The process utilizes air to foam the composition after the air has been treated to lower the oxygen content below that concentration necessary to support combustion. Additionally, the current invention provides a process for completing and/or treating a well bore using a foamed composition wherein the foam is generated with reduced oxygen content air. Finally, a preferred embodiment of the invention provides a foamed cement composition wherein the gaseous portion of the composition is air having a reduced oxygen content.

Abstract: Methods and compositions relating to fluid loss control operations are provided. Examples of compositions may comprise ceramic particulate bridging agents and improved fluid loss control additives, and methods of using those compositions to provide fluid loss control. An embodiment of a method of providing fluid loss control from a first location to a second location may comprise the steps of: providing a treatment fluid comprising ceramic particulate bridging agents, a modified starch composition, and a base fluid; introducing the treatment fluid to the first location; and allowing the treatment fluid to form a filter cake to prevent fluid loss from the first location to the second location.

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: Methods are provided for removing filter cake containing a bridging agent soluble in a carboxylic acid salt from a formation fluids producing zone penetrated by a well bore. The methods basically comprise the steps of introducing in an aqueous carrier liquid a carboxylic acid ester and a base for slowly catalyzing the hydrolysis of the ester and forming a carboxylic acid salt therewith into the producing zone, and allowing the base to catalyze the hydrolysis of the carboxylic acid ester to form the carboxylic acid salt so that the carboxylic acid salt dissolves the bridging agent and the filter cake is removed.

Abstract: Improved methods and compositions for consolidating proppant in fractures formed in subterranean zones are provided. An improvement of this invention comprises using proppant particles having a coating of hardenable resin including a gel breaker. The gel breaker facilitates removal of gelled carrier fluid from the surface of the proppant particles.

Abstract: It is proposed a method for completing an unconsolidated interval, including particulates, in a subterranean formation, including a consolidation steps. The consolidation step is performed by injection of an aqueous solution of colloidal particles with a pH modifier and/or an ionic-strength modifier. A hard gel is formed that holds the particulates together. The consolidation is followed by hydraulic fracturing. Diversion towards area of less permeability may be enhanced by the use of micrometric particles.

Abstract: A method for preferentially treating a subterranean formation having at least one primarily oil producing layer and at least one primarily water producing layer. The method involves the steps of providing a water shut-off gel into the formation to preferentially treat the water producing layers. This is followed by providing a viscoelastic fluid into the formation, where the viscoelastic fluid is broken by hydrocarbon, thereby remaining and viscosifying primarily in the water producing layers. Finally, a reactive fluid, such as an acid fluid, is provided. The reactive fluid treats primarily the oil producing layers because the viscoelastic fluid and the water shut-off gel prevent the reactive fluid from substantially entering the water producing layers.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: Methods of cementing in a subterranean formation include passing a swelling agent to a permeable zone in a subterranean formation. The swelling agent is combined with a carrier fluid before being passed to the permeable zone. Upon contacting an aqueous fluid, the swelling agent swells in the permeable zone. The aqueous fluid may already be present in the subterranean formation, or alternatively, it may be introduced to the subterranean formation after passing the swelling agent into the subterranean formation. The swelling agent substantially inhibits a cement slurry subsequently pumped into the subterranean formation from passing through the permeable zone. The cement slurry therefore continues flowing down through the casing and up through the annulus where it sets and forms a strong cement column.

Abstract: Methods, cement compositions and oil suspensions of powders are provided. The oil suspensions of silica powder comprise silica powder, mineral oil, an oleophilic clay, an oleophilic surfactant and a hydrophilic surfactant.

Abstract: The present invention provides improved methods of cementing and cement compositions. A cement composition of the invention comprises hydraulic cement, silica hydrophobicized with a mixture of organosilicon compounds and water which upon hardening has high shear bond strength.

Abstract: A method is given for completing an interval of an open-hole injection well penetrating a subterranean formation when the interface between the wellbore and the formation includes a zone invaded by a filter cake that includes bridging materials and other embedded solid materials. The method includes the steps of injecting a clean-up fluid and contacting it with the filtercake for a period of time sufficient to loosen some of the other solids embedded in the filter cake; removing the loosened solids by a high-rate displacement fluid containing suspending additives; and then injecting a dissolving fluid containing a diverter and an effective amount of a salt or acid capable of dissolving the bridging material.

Abstract: The present invention relates to foamed cement slurries, additives and methods. A foamed cement slurry of the invention comprises a hydraulic cement, sufficient water to form a slurry, sufficient gas to form a foam and an environmentally benign foaming and stabilizing additive comprising a mixture of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride and water.

Abstract: Methods and compositions for placing particulate materials in subterranean zones penetrated by well bores. In one embodiment, the methods comprise: providing a compacted particulate material fluid that comprises a compacted particulate material, and a foam within the pore spaces of the compacted particulate material, the foam comprising a pressurized gas and a liquid solution of a foam forming surfactant; and pumping the compacted particulate material fluid into the subterranean zone.

Abstract: The invention relates to a grout for making watertight screens which comprises a mixture of water, natural or modified clay, specific blast furnace slag and an activating agent. The invention also relates to a process which makes use of said grout, as well as the use of a specific blast furnace slag for preparing said grout.

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 present invention provides a cement composition and a process for using the cement composition to inhibit gas migration from a subterranean zone into the cement. The process comprises displacing a gelling additive, preferably comprised within a cement composition, into a well bore such that the gelling additive passes into the subterranean zone, and allowing the gelling additive to form a crosslinked gel in the subterranean zone to inhibit gas migration from the subterranean zone. The crosslinked gel acts as a barrier to gas in the subterranean zone and thereby inhibits the gas from passing into the cement and forming flow channels therein before the cement can set.

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

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: A method of fracturing subterranean zones at temperature below about 200° F. wherein the fracturing fluid comprises water, a viscosity increasing gelling agent, a particulate proppant material, a delayed viscosity breaker for causing the fracturing fluid to revert to a thin fluid and a breaker activator comprising a mixture selected from the group of a mixture of cobaltous acetate and the sodium salt of ethylenediaminetetraacetic acid and a mixture of thioglycolic acid and sodium molybdate.