Abstract: A method of reducing fluid loss from a wellbore that includes emplacing a fluid loss pill in the wellbore, the fluid loss pill comprising: a base fluid; a hydratable or solvatable synthetic copolymer having at least one crosslinkable comonomer; and a crosslinking agent is disclosed.

Abstract: A fluid loss pill that includes a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described. Further, a method for reducing fluid loss that includes pumping a selected amount of a fluid loss pill into a wellbore leading to an oil-condensate-, or gas-producing formation, the fluid loss pill including a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described.

Abstract: Compositions for increasing the thermal and pressure stability of well fluids viscosified using viscoelastic surfactants, the compositions including an effective amount of an oligomeric or polymeric compound that has a thermally stable backbone structure and at least one pendent viscoelastic surfactant functional group. Preferred compositions for increasing the stability of well fluids viscosified using monomeric viscoelastic surfactants include an effective amount of an oligomeric or polymeric compound that has a thermally stable backbone structure and a multiplicity of pendent viscoelastic surfactant functional groups attached to said backbone structure through relatively long hydrocarbon chains, 1 to 18 carbons in length.

Abstract: A composition and method for use in drilling or completing a subterranean well comprising a solids free, high-density brine composed of alkali metal polytungstate and blends thereof. These high-density brines are also useful as wellbore fluids and other non-oilfield fluids requiring high density properties.

Abstract: A method of treating a well that includes selectively emplacing a fluid loss pill into the well, wherein the fluid loss pill includes at least one of diethylene glycol, triethylene glycol, and tetraethylene glycol, and wherein the at least one of diethylene glycol, triethylene glycol, and tetraethylene glycol reacts with a calcium brine present in the well to form a plug is disclosed.

Abstract: An annular fluid or packer fluid, and methods of making the same, that includes a water-miscible solvent, a viscosifying additive, a crosslinking agent, a crosslinking inhibitor having the facility to inhibit crosslinking between the viscosifying additive and the crosslinking agent, and an initiating agent having the facility to overcome an action of the crosslinking inhibitor and to initiate crosslinking between the viscosifying additive and the crosslinking agent, is shown and described. The fluid has a thermal conductivity of no more than about 0.25 btu/(hr·ft·° F.) and a potential to substantially increase its viscosity upon sitting for a selected period of time.

Abstract: An annular fluid or packer fluid, and methods of making the same, that includes a water-miscible solvent, a viscosifying additive, a crosslinking agent, a crosslinking inhibitor having the facility to inhibit crosslinking between the viscosifying additive and the crosslinking agent, and an initiating agent having the facility to overcome an action of the crosslinking inhibitor and to initiate crosslinking between the viscosifying additive and the crosslinking agent, is shown and described. The fluid has a thermal conductivity of no more than about 0.25 btu/(hr·ft·° F.) and a potential to substantially increase its viscosity upon sitting for a selected period of time.

Abstract: The present invention is directed to new enzyme breakers for breaking fracturing fluids or blocking gels, wherein the enzyme breakers only have activity above a selected temperature, i.e., no activity below the selected temperature or only active in a narrow temperature range. The present invention is preferably specifically directed to hemicellulase enzyme breakers only having activity above 100.degree. F., 150.degree. F., 200.degree. F., or 250.degree. F. and the method of making and use thereof.

Abstract: A method of fracturing a subterranean formation in a well bore is shown in which a gellable fracturing fluid is first formed by blending together an aqueous fluid, a hydratable polymer, a suitable cross-linking agent for cross-linking the hydratable polymer to form a polymer gel and an encapsulated enzyme breaker. The cross-linked polymer gel is pumped into the well bore under sufficient pressure to fracture the surrounding formation. The encapsulated enzyme breaker is allowed to degrade the cross-linked polymer with time to reduce the viscosity of the fluid so that the fluid can be pumped from the formation back to the well surface. The particular enzyme breaker uses open cellular encapsulation to protect and delay the action of the enzyme.