A Review of Technical Status and Development Expectation of Drilling Fluids for Deep and Ultra-deep Wells
The drilling of deep and ultra-deep wells is conductive to the development of the deep oil and gas ex-ploration.Its main characteristics are as follows:high bottom-hole temperature and great drilling depth,among which the high temperature environment is the main factor limiting large-scale drilling.Considering the influence of high temperature on drilling fluid,this paper analyzes the difficulties faced by ultra-deep drilling fluid from six aspects:rheological control,property change of water molecular,wellbore stability,lost circulation prevention and plugging,drilling friction&pressure reduction and environmental protection property.Moreover,the application and research progress of drilling fluid and treatment agent in deep and ultra-deep wells are reviewed.Finally,the problems existing in the field of drilling fluid research in China are analyzed,and the development trend of drilling fluid technology in deep and ultra-deep wells discussed from the basic theory update,research object adjustment,drilling fluid treatment agent development and other directions.
deep and ultra-deep wellsdrilling fluidhigh temperature resistanceagentsfield applicationde-velopment trend