Interior Research On High-temperature Water-based Drilling Fluid

With the rapid development of the deep well drilling technology, thehigh-temperature resistant drilling fluid has been facing more and more technicalproblems. The quality of drilling fluid is the key of drilling cost，drilling rate and theengineering during the drilling of high temperature deep wells，geothermal wells andoil-gas wells. At the same time，the filter loss performance and rheological control ofdrilling fluid at high temperatures are the difficulties of high temperature resistantdrilling fluid technology.For these reasons above，the study is focused on high temperature resistantdrilling fluid system from the rheological and filtration control of drilling fluid in thiswork. This project relies on the national key subject of deep exploration andexperimental study in the Project “high-temperature drilling fluid system”. Theoverall goal is to develop water-based drilling fluid system and to solve the technicalproblems of domestic deep well drilling，and to solve the problems of ultra-deep welldrilling in the high temperature and high pressure formation. It is the technologicalfoundation for China’s scientific drilling and ultra-deep drilling.This paper has introduced the development status of the existing hightemperature resistant drilling fluid additives and drilling fluid system at home andabroad. Base on the specific analysises on the slurry materials and high temperaturefailure mechanism of high temperature resistant drilling fluid，the mechanisms of hightemperature affecting on the drilling fluid treatment additives and high-temperatureslurry materials are analyzed in detail. It has also comprehensively evaluated the levelof development of Chinese existing slurry materials and high temperature resistanttreatment activities through the experimental test on their anti-high temperature in thelaboratory. It has filtered out nine kinds of high temperature resistant drilling fluidtreatment additives at240℃, and selected four groups of drilling fluid system inwhich the filter loss performances are stable at the high temperature of210℃. The rheological properties and the HTHP filtration are studied. The laboratoryexperiments show that this system has good rheological properties and filtrationperformance under high temperature conditions and can meet the needs ofhigh-temperature formation drilling.