Research on KCl/Polysulfonate Water-based Drilling Fluid System in Deep Well Drilling

In order to solve the following problems in deep well drilling such as high-temperature stability of drilling fluids,mud shale hydration and reservoir protection,according to the selection of the treatment agent,the formula of KCl/Polysulfonate water-based drilling fluid system for deep well drilling is studied in the paper.Furthermore the drilling fluid system is also evaluated from high-temperature stability, anti-pollution capability, anti-collapse capability and reservoir protection in the laboratory.Finally, the selected formula has appropriate rheology under the condition of high temperature and pressure, and the anti-pollution and anti-collapse capability are also very strong.The research is successfully used in the deep well drilling of a oilfield in the eastern,which is significant to the selection of drilling fluid fordeep well.