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: Additives for drilling fluids, in particular for water-based drilling fluids are described which when added to the fluid at levels of up to 10% weight by volume reduces the accretion and bit-balling tendencies of shale cuttings exposed to said fluids. The additives are based on phosphonate chemistry, and are of the general class (I), wherein R, R′ and R″ are radicals exclusively containing H atoms or combinations of H, C, O or P atoms up to a maximum of 100 atoms.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: The present invention relates to a method for inhibiting high temperature of corrosion-prone metal surfaces by organic acid-containing petroleum streams by providing an effective corrosion-inhibiting amount of phosphorous acid, typically up to 1000 wppm, to the metal surface.

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: A one step squeeze treatment of a subterranean formation involves the treatment with a treating solution comprising an acid, a scale inhibitor, and a reducing agent. The presence of the reducing agent prevents the iron ions in the system from reacting with and forming a precipitate with the scale inhibitor and maintains the iron ions in the ferrous state.

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 an aqueous mineral acid solution, an electron donor agent and an electron transfer agent, the electron transfer agent being a source of molybdenum ions. When the aqueous mineral acid solution includes hydrochloric acid in an amount greater than approximately 17% by weight, the acidizing composition further includes a supplemental electron transfer agent, the supplemental electron transfer agent being a source of iodide ion or iodine. The electron donor agent and electron transfer agent 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 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: Methods and compositions for preventing precipitation of iron compounds during acid treatments of wells by catalyzing the rate of iron reduction during such treatments. Reduction of ferric ions is accelerated utilizing co-catalytic amounts of antimony ions in combination with other materials to minimize precipitation and other complications which result from iron compounds during acid treatments. Such other materials may include co-catalytic amounts of copper ions and optional iodide ions; as well as at least one of phosphinic acid, salt of phosphinic acid, or a mixture thereof.

Abstract: According to the present invention, a composition and method for hydraulically fracturing a subterranean formation is provided. The composition comprises an aqueous mixture of a hydrated polysaccharide, preferably a galactomannan gum, the hydrated polysaccharide having a plurality of bonding sites; a crosslinking agent for crosslinking the hydrated polysaccharide at the bonding sites at the conditions of the subterranean formation with a polyvalent metal ion to form a polyvalent metal crosslink, thereby increasing the viscosity of the hydrated polysaccharide; and a controlled solubility compound for releasing a chelating agent for controllably breaking the polyvalent metal crosslink and bonding with the polyvalent metal ion released by breaking the crosslink, thereby decreasing the viscosity of the hydrated polysaccharide.

Abstract: The reaction of compounds of the formula:X.sub.2 O.sub.3 P CHY CZ.sub.2where Y and each Z are each H, PO.sub.3 X.sub.2, SO.sub.3 X or CO.sub.2 X (e.g. vinyl phosphonic acid or vinylidene diphosphonic acid) with hypophosphorous acid in the presence of free radicals provides novel compounds X.sub.2 O.sub.3 PCHYCZ.sub.2 PO.sub.2 XH which react with monomers such as vinyl sulphonate, vinyl phosphonate, vinylidene diphosphonate and acrylic acid to form telomers useful for scale inhibition, especially barium scale in oil wells. The polymers show better absorption to rock than PVSA and better thermal stability than random copolymers containing equivalent phosphorus.