New environmentally safe high-temperature water-based drilling-fluid system

A new, environmentally safe water-based polymer system has been developed f or drilling applications with temperatures up to 232 degrees C (450 degrees F) and high pressures. The system components are newly developed synthetic polymers that do not contain chromium or other environmentally harmful mat erials. These new synthetic polymers are designed to perform specific funct ions at high temperatures and the innovative designs of these thermally sta ble polymers allow for the use of a minimum number of products in the formu lation of high-temperature fluids. The new system consists of two basic polymeric components for rheology and filtration control at high temperatures. High-temperature fluid formulation s are greatly simplified utilizing this new system, with only the two polym eric components being required, along with a pH control additive, weight ma terial, and small amounts of clay for filter cake quality. This simplicity is a significant advantage over "traditional" high-temperature systems, whi ch normally require the use of a large number of additives to control or li mit the effects of thermal degradation. The new system may be formulated with fresh water or sea water, providing f lexibility for a variety of drilling environments. Excellent resistance to common contaminants, such as calcium and magnesium hardness and solids accu mulation, is another important characteristic of this new system. This paper will review the previous state of the art with respect to high-t emperature, water-based muds and will generically discuss the unique chemis try of the newly developed polymer system components. System formulation an d application will be discussed.