Abstract: A thinner that is a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid is able to reduce the viscosity of oil-based drilling fluid, thus allowing for reuse of the oil-based drilling fluid.

Abstract: A thinner that is a poly fatty amide reacted with maleic acid to form a product, and diluting the product with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty acid is able to reduce the viscosity of oil-based drilling fluid, thus allowing for reuse of the oil-based drilling fluid.

Abstract: Crosslinked high molecular weight acrylamide and 2-acrylamido-2-methylpropane sulfonic acid copolymers in inverse emulsion form act as inhibitive and encapsulating agents for water-based drilling fluids system. The crosslinked copolymer are particularly useful for high salt, high density drilling fluids in high temperature and high pressure applications.

Abstract: A thinner that is a poly fatty amide reacted with maleic acid to form a product, and diluting the product with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty acid is able to reduce the viscosity of oil-based drilling fluid, thus allowing for reuse of the oil-based drilling fluid.

Abstract: A thinner that is a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid is able to reduce the viscosity of oil-based drilling fluid, thus allowing for reuse of the oil-based drilling fluid.

Abstract: Crosslinked high molecular weight acrylamide and 2-acrylamido-2-methylpropane sulfonic acid copolymers in inverse emulsion form act as inhibitive and encapsulating agents for water-based drilling fluids system. The crosslinked copolymer are particularly useful for high salt, high density drilling fluids in high temperature and high pressure applications.

Abstract: A fluid having utility in subterranean wells is formulated to include: an oleaginous fluid; and a solids tolerance agent having the formula: in which R is a C6 to C20 aliphatic group and R′ is a C2 to C6 aliphatic group and x has a value from about 1 to about 10. Preferably R′ is selected from ethyl and isopropyl and R is an unsaturated aliphatic group. The fluid is formulated such that the oleaginous fluid is from about 30% to about 99% by volume of said fluid. In one illustrative embodiment, the oleaginous fluid is composed from about 5% to about 100% by volume of the oleaginous fluid of a material selected from a group consisting of diesel oil, mineral oil, synthetic oil, esters, ethers, acetals, di-alkylcarbonates, olefins, and combinations of these and similar fluids. A non-oleaginous fluid may also be included in the formulation that is from about 1% to about 70% by volume of said fluid.

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: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. 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. The electrolytic salt or brine preferably includes a quaternary amine salt having the formula: wherein R is an alkyl having 8 to 18 carbon atoms, R′ is 2 to 6 carbon atoms alkyl group, B is hydrogen, oxyalkyl having 1 to 4 carbon atoms or alkyl having 1 to 4 carbon atoms, A is hydrogen or alkyl with 1 to 4 carbon atoms, x+y=1 to 15, z is 0 to 3, and M is a counter anion; or combinations thereof. The carbon dioxide buffer is preferably a trialkylanol amine.

Abstract: A method of electrically logging subterranean wells using a conductive fluid in which the conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, and an electrolytic salt. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The medium may further include gelling agent, weight material, surfactant, or corrosion inhibitors. The polar organic solvent may preferably be a oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. 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.