Abstract: Disclosed are spacer fluids and methods of use in subterranean formations. Embodiments may include use of consolidating spacer fluids in displacement of drilling fluids from a well bore annulus. Embodiments may include determining the boundary between a cement composition and a consolidating spacer fluid based on presence of tagging material in the well bore.

Abstract: Disclosed are foamed spacer fluids comprising kiln dust for use in subterranean formations. An embodiment discloses a foamed spacer fluid comprising a partially calcined kiln feed removed from a gas stream comprising SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Na2O, and K2O; a foaming agent; a gas; and water.

Abstract: Disclosed are spacer fluids comprising cement kiln dust (“CKD”) and methods of use in subterranean formations.

Abstract: Disclosed are spacer fluids and methods of use in subterranean formations. Embodiments may include use of consolidating spacer fluids in displacement of drilling fluids from a well bore annulus.

Abstract: Disclosed are spacer fluids comprising cement kiln dust (“CKD”) and methods of use in subterranean formations. An embodiment discloses a method comprising: providing a foamed spacer fluid comprising CKD, a foaming agent, a gas, and water; and introducing the foamed spacer fluid into a well bore to displace at least a portion of a first fluid present in the well bore. Another embodiment discloses a method comprising: providing a foamed spacer fluid comprising a partially calcined kiln feed removed from a gas stream, a foaming agent, a gas, and water, wherein the partially calcined kiln feed comprises SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Na2O, and K2O; and introducing the foamed spacer fluid into a well bore to displace at least a portion of a first fluid present in the well bore.

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: A method of treating a well consists of introducing into the wellbore a biodegradable fluid system containing a fatty acid ester, such as methyl soyate. The fluid system may further contain a lactic acid ester, such as ethyl lactate, and/or a nonionic surfactant. The fluid system may be used in displacement, well remediation and stimulation as well as additional, alternative applications such as the cleaning of surface and/or downhole equipment.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean operations, are provided. An example of a method is a method of cementing a pipe string in a subterranean formation. Another example of a method is a method of cementing a pipe string in a well bore. An example of an apparatus is an improved pipe string comprising at least one pipe section; and a delivery system of an activator; wherein the delivery system of an activator is disposed adjacent an outer surface of the at least one pipe section.

Abstract: A method of treating a well consists of introducing into the wellbore a biodegradable fluid system containing a blend of lactic acid ester, such as ethyl lactate, and a fatty acid ester, such as methyl soyate. The fluid system may be further in the form of a microemulsion that is formed by combining a blend with one or more emulsifiers, an alcohol, and water. The fluid system may be used in displacement, well remediation and stimulation as well as additional, alternative applications such as the cleaning of surface and/or downhole equipment.

Abstract: The present invention relates to spacer fluids used in subterranean operations and, more particularly, to spacer fluids that comprise water-soluble relative permeability modifiers and methods of using the spacer fluids in subterranean operations. In one embodiment, the present invention provides a method of displacing a first fluid from a well bore that comprises introducing the first fluid into the well bore; and displacing the first fluid with a spacer fluid, the spacer fluid comprising water, and a water-soluble relative permeability modifier comprising a hydrophobically modified polymer or a hydrophilically modified polymer. In another embodiment, the present invention provides a spacer fluid that comprises water, and a water-soluble relative permeability modifier comprising a hydrophobically modified polymer or a hydrophilically modified polymer.

Abstract: Fluid producing wells may be treated with a water-in-oil emulsion for the removal or inhibition of unwanted solid particulates, including pipe dope, asphaltenes and paraffins. Such emulsions are of particular applicability in the displacement of oil base drilling muds and/or residues from such muds from producing wells. The water-in-oil emulsions may optionally contain a dispersing agent as well as a surfactant.

Abstract: Well completion spacer fluids containing fibers and methods of using the spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the spacer fluid are displaced from the well bore with the second fluid. The spacer fluid comprises water, a weighting material, a dispersing agent, a suspending agent and friction reducer and fibers. The spacer fluid containing the components mentioned above is preferably also foamed.

Abstract: A method and composition is provided for a relative permeability modifier for use with aqueous well treatment fluids that comprises a hydrophobically modified water soluble polymer or a hydrophilically modified water soluble polymer.

Abstract: A storable cement system comprises a suspending agent, a cement spacer and water. The composition may further optional contain a surfactant and/or an organic solvent and/or a weighting material. The suspending agent is preferably a carrageenan or scleroglucan. The cement system may be stored for an extended period of time prior to being interposed between a cement slurry and a drilling fluid. As such, the aqueous cement system may be made off-site and used when desired for preventing contact between non-compatible hydrocarbonaceous and aqueous fluids.

Abstract: A method of and product for use in cementing the annulus of a hydrocarbon well having a casing centered within a hole bored from a surface. The method comprises the steps of introducing an effective amount of colouring agent contained in a water-soluble bag into a portion of spacer or scavenging fluid, pumping the spacer or scavenger and a then cementing slurry down the casing to the bottom of the hole to displace drilling mud upwardly through the annulus to the surface, until the colouring agent becomes visible at the surface, displacing the casing volume and then stopping the pumping and allowing the pumped cement slurry to harden.

Abstract: The present invention provides methods and compositions for removing a water-based drilling fluid from surfaces in a well bore and leaving the surfaces water-wet. A method of the invention basically comprises the following steps. A water-based drilling fluid removal solution comprised of water and a mixture of a sulfonated kraft lignin salt and an N-methyl-N-oleyltaurine salt dissolved therein is provided. The drilling fluid is displaced from the well bore and the well bore surfaces are contacted with the removal solution to thereby remove the drilling fluid from the surfaces and make the surfaces water-wet.

Abstract: Oil-based settable spotting fluid compositions for cementing in wells and subterranean formations are provided. The oil-based settable spotting fluid compositions basically comprise an oil external emulsion comprising oil, water and an emulsifying surfactant, a hydraulically settable component and a de-emulsifying surfactant for de-emulsifying the oil-external emulsion when the emulsion is cured.

Abstract: Well completion foamed spacer fluids and methods of using the foamed spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A foamed spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the foamed spacer fluid are displaced from the well bore with the second fluid.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: Methods for drilling well bores and cementing a pipe string in the well bores using oil-based settable drilling fluids are provided. The oil-based settable drilling fluid compositions basically comprise an oil external emulsion comprising oil, water and an emulsifying surfactant; a hydraulically settable component; and a de-emulsifying surfactant for de-emulsifying the oil-external emulsion when the emulsion is cured.

Abstract: The present invention provides methods and compositions for removing a water-based drilling fluid from surfaces in a well bore and leaving the surfaces water-wet. A method of the invention basically comprises the following steps. A water-based drilling fluid removal solution comprised of water and a mixture of a sulfonated kraft lignin salt and an N-methyl-N-oleyltaurine salt dissolved therein is provided. The drilling fluid is displaced from the well bore and the well bore surfaces are contacted with the removal solution to thereby remove the drilling fluid from the surfaces and make the surfaces water-wet.

Abstract: Oil-based settable spotting fluid compositions and methods of using the compositions are provided. The oil-based settable spotting fluid compositions are basically comprised of oil, an emulsifying surfactant for emulsifying the oil with water whereby an oil-external emulsion is formed, a de-emulsifying surfactant which in time de-emulsifies said oil-external emulsion when the emulsion is contacted with external water, a hydraulic settable component selected from the group consisting of ASTM Class C or the equivalent fly ash and ASTM Class F or the equivalent fly ash together with a source of calcium and water selected from the group consisting of fresh water and salt water.

Abstract: A method of preventing corrosion in pipelines comprising draining pipeline of all residual compounds, blowing through with nitrogen and rinsing with a corrosion inhibiting rinsing agent.

Abstract: Methods of treating wells for cementing operations and for improving placement of cement in wells containing water swelling clays include treatment of the well with a fluid containing clay precipitating agents capable of coagulating clays in the well. The coagulating fluid can contain quaternary ammonium salts, aqueous salts of potassium or cesium, or silicates as the clay coagulating agent. The coagulating fluids can be applied to convert soft mud cake into hard mud cake prior to placement of cement.

Abstract: The invention relates to a process for drying out rock containing immobile formation water in the intake radius of natural gas wells and gas storage wells which deliver less than 50 l of water per 1000 m.sup.3 (S.T.P.) of natural gas produced, in which a dispersion comprising the componentsA) a water-repellent active compound,B) hydrophilic water-miscible dispersion medium, with or withoutC) a dispersant renders the water-containing rock hydrophobic.

Abstract: This invention is a process and a formulation for minimising the squeezing and shut-in operations needed to inhibit scale in a production well using the precipitation squeeze method by injecting into an oil-bearing rock formation a water-miscible formulation comprising: (a) a water-miscible surfactant which is in liquid form, (b) a solution of water-soluble metal salt comprising a multivalent cation and (c) a solution of a water-miscible scale-inhibiting compound comprising an anionic component capable of forming a scale-inhibiting precipitate in situ in the presence of the cations in (b) upon injection into the rock formation, wherein the surfactant is a glycol ether and the minimum ion concentration of the scale inhibiting compound (c) is 50 ppm based on the total weight of the formulation.

Abstract: Improved settable spotting fluid compositions and methods are provided. The settable spotting fluid compositions are basically comprised of a hydraulic settable component comprised of fly ash, a fluid loss control additive, a gel strength inhibiting additive, a set retarding additive and water selected from the group of fresh water and salt water present in an amount sufficient to form a slurry having a density in the range of from about 12 to about 15 pounds per gallon.

Abstract: An aqueous displacement fluid composition is used as a spacer fluid composition to change one type of drilling mud for another type of drilling mud or in cementing operations downhole, to clean downhole hardware in wellbores. The method comprises introducing into a wellbore an aqueous displacement fluid composition, such as a spacer fluid, to displace downhole wellbore fluids, having an improved rate of emulsification and a high capacity for emulsifying hydrocarbons, and aqueous fluid compositions. The aqueous displacement fluid composition introduced into wellbores contain mixtures of:a) water;b) a polyoxyalkylene monool surfactant represented by the formula: ##STR1## wherein R.sub.1 is a hydrocarbyl group, R.sub.2 is a C.sub.1 -C.sub.3 alkyl group, and the weight average of w+x is at least about 5; andc) a polyoxyalkylene monool surfactant represented by the formula: ##STR2## wherein R.sub.1 is a hydrocarbyl group, R.sub.2 is a C.sub.1 -C.sub.

Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, an acid and an alkyl alcohol.

Abstract: Wellbore fluids are disclosed which comprise liquid dispersions of particulate mixed divalent metal carbonates having a generally platy crystal form. Mixed alkaline earth metal carbonates are preferred. The invention further relates to a method of well construction, well remediation, or stimulation utilizing such wellbore fluids.

Abstract: A non polluting additive or spotting fluid which lubricates, releases and/or prevents differentially stuck drill strings and casings in the wellbore of a subterranean well is presented. This additive composition comprises a glycol or glycol ether derived from a long chain epoxide of greater than 3 carbon atoms (preferably greater than 10 carbon atoms); and preferably comprises the reaction product between 2-ethylhexanol and the epoxide of 1-hexadecene. The present invention enhances the lubricity of a drilling fluid to prevent drill string sticking and when utilized as a spotting agent reduces the time required to release a stuck pipe. This invention also helps reduce or prevent foaming. By eliminating the need for traditional oil-based components, the present invention is nontoxic to marine life, biodegradable, environmentally acceptable, easy to prepare, and capable of being disposed of at the drill site without costly disposal procedures.

Abstract: Spacer fluids comprising a dispersant selected from the group consisting of water soluble polymers comprising allyloxybenzene sulfonate or allyloxybenzene phosphonate polymerized with at least one of acrylic acid, acrylamides, alkyl acrylamides, maleic anhydride, itaconic acid, sulfonated or phosphonated styrene, sulfonated or phosphonated vinyl toluene, sulfonated or phosphonated isobutylene, acrylamidopropane sulfonate or acrylamidopropanephosphonate, vinyl alcohol, sulfonated or phosphonated propene and alkali metal, alkaline earth metal and ammonium salts thereof and water with optional additional components such as surfactants, viscosifiers and wetting materials to form a rheologically compatible spacer fluid for use between a drilling fluid and a cement slurry and a method for using such spacer fluids to displace drilling fluids from a wellbore space with a cement slurry.

Abstract: Blends of alkyl polyglycoside surfactants having an alkyl chain length of C11 to C16 and blends of alkyl polyglycoside surfactants, in the presence of an ethoxylated alcohol cosurfactant, will form Winsor type III microemulsions in a water-oil mixture in a hydrophile-lipophile balance range of at least about 9.8 to 10.8 at 130.degree. F. wherein the water may be a chloride brine. The compositions are particularly useful in oil and gas well cleanout operations, formation acidizing, and well cementing operations and provide superior cleaning ability for removal of oil based drilling fluids, hydrocarbons and oil based pipe sealant and lubricant compositions, for example.

Abstract: A well completion spacer fluid is provided which is particularly suitable for separating a cement slurry from drilling fluid in primary cementing operations. The well completion spacer fluid is also useful for separating other potentially incompatible fluids in the wellbore, such as, separating drilling fluid from a completion brine. The spacer fluid basically comprises water, a hydrous magnesium silicate clay, silica and organic polymer(s).

Abstract: A process for cleaning a well system and equipment has been developed using a chemical additive that includes an alkene alcohol, preferably a terpene, and either an ether amine or base fluid or combination of the two. The additive can be used in an aqueous or salt solution. The process includes circulating the chemical additive in the well system with spacer fluids.

Abstract: Methods and compositions for removing gelled and dehydrated drilling fluid and filter cake from the walls of wellbores are provided. The methods basically include contacting the drilling fluid and filter cake with a removal composition comprised of an aqueous sugar solution for a period of time sufficient to cause the disintegration of the drilling fluid and filter cake. The composition, having the disintegrated drilling fluid and filter cake dispersed therein, is then displaced from the wellbore.