Abstract: A wellbore fluid composition effective to reduce oil-containing residue and water wet wellbore surfaces is provided. The fluid composition comprises a terpene composition and a surfactant. Methods for use of the fluid composition as a single spacer or as a multiple spacer in conjunction with a second fluid are provided. Methods for use of the composition in reduction or removal of oil-containing residue from wellbore surfaces, as a clean-up fluid, in wellbore completions, as a displacement fluid, and in wellbore treatment are provided.

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: A fluid that is useful in stimulation operations, and in particular, in hydraulic fracturing treatments, comprises a carrier fluid; a solvatable, crosslinkable polymer; a cross-linking agent that does not cause substantial cross-linking of the polymer at temperatures less than about 105° F. and a pH of about 10 or greater; and an organic amine stabilizing agent that has a first pKa or a pH in water of at least about 9.5. One group of such amines has the formula H2N—(R1NH)n—H where R1 is C1-C4 alkyl and n is from 1-6. In one embodiment, the cross-linking agent is an organic zirconate, such as bis(hydroxyethyl)glycine zirconate. The organic zirconate is effective to cross-link the polymer when the composition is at a temperature of at least about 105° F., and a pH of about 10 or higher, preferably a pH in the range of about 10.5-12.

Abstract: The present Invention relates to method to stimulate the production of hydrocarbons from a subterranean formation. In particular, the present Invention discloses and claims methods to enhance the removal of fracturing fluid from a fracture deliberately created in the formation, thereby increasing effective fracture length, and thereby increasing hydrocarbon production. The methods of the present Invention involve breaker schedules opposite conventional teaching—i.e., according to the Invention, the breakers are staged such that the fluid near the fracture tip breaks first creating a viscosity gradient which causes the fluid resident in the tip to move towards the wellbore where it is more easily removed.

Abstract: A wellbore service fluid comprising viscoelastic surfactants in combination with cross-linkable, preferably hydrophobically modified, water soluble polymers is described, particularly applicable to water control operations.