Clay-Free Invert Fluid in High-Temperature Well Provides Consistent Low ECD Profile

摘要

Historically, invert-emulsion drilling fluids (IEFs) require organophilic clays to provide viscosity and suspension characteristics. While effective, these chemicals are prone to stratification in certain conditions, slow chemical-reaction times, high pressure spikes, and high equivalent circulating densities (ECDs). This paper describes the first application of clay-free IEFs in the Norwegian continental shelf (NCS), with an emphasis on an impressively low and consistent ECD contribution. Further, a treatment was developed to allow the IEFs to be used to drill into a section exhibiting temperatures greater than 160°C.