An engineering approach to characterizing synthetic-based drilling fluids for deepwater and extended reach drilling applications

Rheological techniques currently employed to characterize drilling fluids are based upon models and instrumentation that were in existence over forty years ago. A great deal of literature exists that questions the degree to which these techniques address the requirements placed on drilling muds in today`s drilling environment. The solution to many of the problems facing companies operating in deepwater requires an in-depth understanding of the rheological properties of synthetic-based drilling muds. These problems include lost circulation, hole cleaning and barite sag. This paper discusses the application of sophisticated rheological instrumentation and techniques that specifically address the needs of deepwater drilling operations. Focus has been placed on studying the gel structure of synthetics, particularly at low temperatures, in order to provide engineered solutions to get strength-related problems encountered in deepwater.