Drilling mud additive comprising ferrous sulfate and poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate)
AssigneePhillips Petroleum Company
InventorsBharat B. Patel, George G. Dixon
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Abstract
A water based drilling fluid composition and an additive for water based drilling fluid compositions having as components poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) and ferrous sulfate useful in controlling high temperature water loss in drilling a well to recover oil and gas from a subterranean formation in a hostile environment and their methods of use.
Claims16
An additive for water based drilling fluid compositions, said additive comprising poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) and an amount of ferrous sulfate sufficient to reduce drilling fluid viscosity as compared to a drilling fluid comprising poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) without said ferrous sulfate.
A water based drilling fluid composition comprising poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) and an amount of ferrous sulfate sufficient to reduce drilling fluid viscosity as compared to a drilling fluid comprising poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) without said ferrous sulfate.
A method for controlling high temperature water loss in a hostile environment comprising circulating in said hostile environment a drilling fluid comprising poly-(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) and an amount of ferrous sulfate sufficient to reduce drilling fluid viscosity as compared to a drilling fluid comprising poly(N-vinyl-2-pyrrolidone/sodium2-acrylamido-2-methylpropane sulfonate) without said ferrous sulfate.
A method of drilling a well to recover oil and gas from a subterranean formation in a hostile environment comprising circulating in the well while drilling a drilling fluid comprising poly-(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) and an amount of ferrous sulfate sufficient to reduce drilling fluid viscosity as compared to a drilling fluid comprising poly(N-vinyl-2-pyrrolidone/sodium 2-acrylamido-2-methylpropane sulfonate) without said ferrous sulfate.
Dependencies are inferred from the claim text.