This paper discusses a new, environmentally safe, water-based polymer drilling fluid that has been developed for offshore drilling applications with temperature resistance to 200°C and low biological toxicity. The system comprises two basic polymeric components for high-temperature rheology and filtration control, along with a special nanoplugging agent, glycol shale inhibitor, extreme-pressure lubricant, and barite or formate weight material. The base slurry is light-colored and nontoxic to the marine environment, and so can be discharged directly into the sea. Results from field testing in a Bohai offshore oil field are presented in the complete paper.
Introduction
Historically, significant limitations have been placed on the use of drilling fluids in high-temperature operations in environmentally sensitive areas of China.
