Research and Application of Salt-resisting and High Temperature Resisting and Water Base Drilling Fluid System

To meet the requirement of deepwater exploration well drilling techniques to drilling fluids used for drilling in complex formation. An experimental study is carried out on a water-base drilling fluid system for salt-resisting and high temperature resisting deep well drilling, 2 sets of drilling fluid formulae are established. The temperature resisting performance, precipitation stability, mud cake sealing performance, wettability, inhibition property and pollution resistance of the drilling fluid are evaluated. The result shows that is temperature resistance is as high as 200℃. After it is exposed for 48h, its density tolerance is less than 0.05g/cm~3, mud cake permeability is less that 0.5×10~ -3 μm~2, its adhesive factor is less than 0.1, it is resistant for 0.1% CaCl_2, 0.1% MgCl_2 and 10% NaCl. It is used in 3 wells with good effect.