Successful Application of MMH Fluid to Drill in Narrow Pressure Window, Ultra Deepwater Situation. A Case History

摘要

A mixed metal oxy hydroxide (MMH-type) system, which exhibits unique flow and gelation characteristics, was used to successfully drill an ultra deepwater well offshore Brasil. Depsite ECD values that exceeded the measured leak off pressure and the calculated fracture threshold for the shale, no losses of fluid to the ofrmation were reported. Subsequently rheological investigations of laboratory-prepared and field fluids were carried out under temperature and pressure conditions similar to those encountered on the subject well. The study unveiled unusual temperature responses of some key rheological measurements. This phenomenon may have played a part in the successful completion of the application discussed. Further wrok is being undertaken to better understand both this phenomenon and its implications for field application. This paper discusses the development and application of he MMH fluid that is now a real alterantive for the operator in deepwater applications where narrow pressure window circumstances have to be addressed.