Abstract: Compositions of oil-based biodegradable drilling fluids are described, the compositions comprising an oil phase composed by methyl esters of soybean oil fatty acids, an aqueous phase finely dispersed in the oil phase by specific emulsifiers and several other additives having specific functions for providing suitable performance to the finished drilling fluid composition. The process to manufacture the inverted emulsion and the drilling process that employs the compositions of the invention are described too.

Abstract: A superior powder form of a metallic soap for enhancing the properties of an invert emulsion drilling fluid may be prepared by a dry process saponification reaction. The process includes mixing a source of metal cations with the product of a Diels-Alder reaction of dienophiles with fatty acids and/or resin acids and allowing the mixture to react. Heating the mixture increases the rate of reaction. The solid product is ground to form a powder. The properties of the drilling fluid that may be improved by adding the soap include filtration control, fluid loss control, emulsification and emulsion stability, and electrical stability.

Abstract: Non-polymeric drag reducing agents in the form of maleated fatty acids and the esters thereof and the organic, inorganic or amine salts thereof are described herein. These additives are useful to reduce drag in hydrocarbon fluids and multi-phase fluids of hydrocarbon(s) and water. No injection probes or other special equipment is expected to be required to introduce the drag reducing agent into the liquid stream, nor is grinding (cryogenic or otherwise) of the additive necessary to form a suitable drag reducing agent. The drag reducing additives of the invention are not subject to shear degradation and do not cause undesirable changes in the emulsion or fluid quality of the fluid being treated, or undesirable foaming.

Abstract: Drilling, completing or workover of a well, particularly an oil and/or gas well, is carried out using a fluid which includes a continuous phase including an ester 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 drilling, completion and/or workover of wells.

Abstract: A method and product is disclosed which provides emulsion stability and filtration control to invert emulsion drilling fluids. The product comprises a blend of a carboxylic acid terminated polyamide and/or a wetting agent with a reaction product or mixture produced by the Diels-Alder reaction of dienophiles, preferably carboxylic acids, polycarboxylic acids, acid anhydrides, or combinations or mixes thereof, with a mixture of fatty acids and resin acids. The product of the invention is extremely effective, decreasing by about two-thirds the amount of emulsifier generally required to formulate an effective drilling fluid. The product of the invention also greatly reduces and in many cases eliminates the need for conventional fluid loss additives, and additionally provides electrical stability.

Abstract: A method is disclosed that affords improved stability to wellbores during drilling in argillaceous formations with water-based drilling fluids. The method comprises adding to the drilling fluid a compound of the invention having the capacity in water to generate a highly efficient membrane on argillaceous materials. The compound is soluble in the drilling fluid at least at the pH at which the compound is added to the drilling fluid or exists in the drilling fluid, but is insoluble in the water in the pores of the argillaceous formations, or at least at the pH of the water in such pores.

Abstract: A method for drilling, running casing in, and/or cementing a borehole in a subterranean formation without significant loss of drilling fluid is disclosed, as well as compositions for use in such method. The method employs a drilling fluid comprising a fragile gel or having fragile gel behavior and providing superior oil mud rheology and overall performance. The fluid is especially advantageous for use in deep water wells because the fluid exhibits minimal difference between downhole equivalent circulating density and surface density notwithstanding differences in drilling or penetration rates. When an ester and isomerized olefin blend is used for the base of the fluid, the fluid makes an environmentally acceptable and regulatory compliant invert emulsion drilling fluid. The fluid preferably contains no organophilic clays.

Abstract: The invention relates to water based wellbore fluids used during a hydrocarbon recovery process, such as drilling, fracturing, gravel packing and wellbore workover. According to the present invention, said wellbore fluid comprises a fluid loss additive and a bridging material that are hydrophobic in nature, hydrophobically modified or oil wettable. The wellbore fluid generates an active filter cake that once formed, is impermeable to an aqueous phase, thus reducing fluid loss and ensuring reduced damage to the formation, yet simultaneously is permeable to the back flow of hydrocarbons during a hydrocarbon recovery process.

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: A low molecular weight, high melting point, crystalline, oil soluble additive for use in wellbore fluids is provided that is preferably a ground crystalline material of melting point over 80° C., preferably over 100° C. which is readily soluble in produced hydrocarbons such as crude oil and lighter condensates, and which exhibits a molecular weight of less than 1000, and preferably less than 500, and more preferably less than 300. Its particle size can be adjusted to bridge efficiently across different pore size formations and control its solubility rate.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity of not less than 10 &mgr;S m−1 at 1 kHz comprises a polar organic liquid (POL) which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cm−3)1/2. Oils or other organic liquids (OL) known to be suitable as the continuous liquid phase of wellbore fluids, may be used in admixture with POL component. Certain inorganic salts, organic bases, quaternary ammonium salts or hydroxides (the dissolved component, DC), display sufficient solubility (and current carrying abilities) in POL, OL or in mixtures of liquid (POL) and liquid (OL) to further improve the electrical conductivity of the mixture. The wellbore fluid can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: A method and product is disclosed which provides emulsion stability and filtration control to invert emulsion drilling fluids. The product comprises a blend of a carboxylic acid terminated polyamide and a mixture produced by the Diels-Alder reaction of dienophiles, preferably carboxylic acids, polycarboxylic acids, acid anhydrides, or combinations or mixes thereof, with a mixture of fatty acids and resin acids. The product is extremely effective, decreasing by about two-thirds the amount of emulsifier generally required to formulate an effective drilling fluid. The product also greatly reduces and in many cases eliminates the need for conventional fluid loss additives, and additionally provides electrical stability. Moreover, the product has a pour point as low as about 20 degrees Fahrenheit with minimal solvents, thereby eliminating the need to ship large amounts of inert material for use, and may be transported in a highly active state.

Abstract: Non-polymeric drag reducing agents in the form of maleated fatty acids and the esters thereof and the organic, inorganic or amine salts thereof are described herein. These additives are useful to reduce drag in hydrocarbon fluids and multi-phase fluids of hydrocarbon(s) and water. No injection probes or other special equipment is expected to be required to introduce the drag reducing agent into the liquid stream, nor is grinding (cryogenic or otherwise) of the additive necessary to form a suitable drag reducing agent. The drag reducing additives of the invention are not subject to shear degradation and do not cause undesirable changes in the emulsion or fluid quality of the fluid being treated, or undesirable foaming.

Abstract: The present invention relates to an oil-based drilling fluid, a continuous phase for an oil-based drilling fluid, and additives for an oil-based drilling fluid. The drilling fluid, the continuous phase of the drilling fluid, and the additives for the oil-based drilling fluid are characterized by non-fluorescence (defined as a fluorescence intensity of 800 or less) when exposed to ultraviolet light. The continuous phase of the drilling fluid is composed of synthetic hydrocarbons selected from the group consisting of oligomers synthesized from one or more alphaolefins containing a C.sub.2 to C.sub.14 chain length, wherein the oligomers have an average molecular weight of from 120 to 100, and additives. The additives of the continuous phase include surfactants, wetting agents and/or emulsifiers.

Abstract: A well treatment fluid comprising a mixture of (A) a major amount of a first hydrocarbon fluid, the first hydrocarbon fluid being composed predominantly of diaromatics and triaromatics having more than 16 carbon atoms, and (B) a minor amount of a second hydrocarbon fluid, the second hydrocarbon fluid being composed predominantly of hydrocarbons having from 7 to 12 carbon atoms. The mixture preferably has a density greater than 1000 kg/m.sup.3 at 15.degree. C. and a viscosity lower than 30 centiStokes at 20.degree. C. In a method according to the invention, a kill fluid is formed by mixing the first and second hydrocarbon fluids to produce a hydrocarbon mixture, preferably having a viscosity of less than 30 centiStokes at 20.degree. C. and a density above 1000 kg/m.sup.3 at 15.degree. C.

Abstract: Reduction of the adhesion of polyethercyclicpolyol (PECP) to metals by preparing the PECP by condensing polyol molecules by reactive distillation and replacing part of the polyol with an alcohol of lower hydroxyl content than the polyol.

Abstract: Solids-free, essentially all-oil and invert emulsion wellbore fluids are employed in well drilling, completion, and workover operations. Techniques for remediating dense aromatic solvents wellbore fluids entail removal and/or dissolution of particulate matter.

Abstract: Reducing the adherence of polyethercyclicpolyol to metal by exposing the metal to a selected surfactant.

Abstract: A non-toxic, inexpensive synthetic fluid for use in wellbore fluids (e.g., drilling fluids) is selected from the group consisting of (A) fluids having (I) a pour point greater than about -30.degree. C. (-22.degree. F.) and (II) a cetane index greater than 50, and comprising (i) at least about 95 weight percent hydrocarbons containing 11 or more carbon atoms, (ii) greater than 5 weight percent hydrocarbons containing 18 or more carbon atoms, (iii) at least about 50 weight percent isoparaffins, (iv) at least about 80 weight percent total paraffins, (v) less than 10 weight percent naphthenics, (vi) less than 0.1 weight percent aromatics, and (vii) at least 2 hydrocarbons containing a consecutive number of carbon atoms, and (B) fluids comprising (i) at least about 95 weight percent hydrocarbons containing 10 or more carbon atoms and (ii) at least about 90 weight percent n-paraffins.

Abstract: A drilling fluid additive comprises a monocyclic terpene, preferably d-limonene or dipentene, a bycyclic terpene such as 3-carene, or mixtures thereof and an oil such as mineral oil or vegetable oil. The additive is mixed in a water based drilling mud in the range of 1-8% by volume. The additive has a number of advantages, particularly improved penetration rate, high lubricity and low toxicity.

Abstract: A method of making a well fluid for use in a well which includes the steps of determining uphole and downhole operating temperatures in the well, and then contacting a well lubricant with a lubricating additive, wherein the lubricating additive has a cloud point temperature greater than the uphole operating temperature and less than the downhole operating temperature. A method of lubricating drilling equipment during opeation of a subterranean well, includes the steps of determining uphole and downhole operating temperatures in the well, and then contacting the drilling equipment with a treating fluid comprising a well lubricant and a lubricating additive, with the lubricating additive having a cloud point temperature greater than the uphole operating temperature and less than the downhole operating temperature.

Abstract: A drilling fluid comprises a continuous phase of diesel oil, mineral oil, ester, mono-ether, di-ether, poly-alpha-olefin, detergent alkylate, terpene and mixtures thereof. Water is added to make an inverted emulsion. In the non-terpene based drilling fluids, terpene or terpenes is added in the amount of 1-80% by volume to increase the penetration rate and provide other advantages, such as rapid biodegradability. The terpene may be of the unsaturated type or the saturated type.

Abstract: The present invention relates to an improved continuous phase for an oil based drilling fluid and specifically a synthetic hydrocarbon continuous phase which is non-polluting and minimally toxic. The invention provides excellent drilling fluid properties under a wide variety of drilling conditions. The synthetic hydrocarbons are selected from the group consisting of branched chain oligomers synthesized from one or more olefins containing a C.sub.2 to C.sub.14 chain length and wherein the oligomers have an average molecular weight of from 120 to 1000. In the drilling fluid compositions, suitable emulsifiers, wetting agents, viscosifiers, weight materials and fluid loss additives are utilized in conjunction with water and/or a brine phase for the desired rheological properties.