Application of temperature resistant polymer-sulfonate KCl mud system on Well FX in Iran

Because of easy hydrate expansion in the upper stratum of YADA area, and complex pressure system and high bottom hole temperature in the lower stratum of YADA area, the deep well complexity problems are easy to occur, such as wellbore collapse, circulation loss, blowout, bit sticking, and the difficulty to run casing. The temperature resistant polymer-sulfonate KCl mud system was developed and the formula was evaluated and optimized, referring to the domestic experience. The application of the mud system in well FX showed the system had good inhibition, high blocking capacity, good temperature resistance, and good lubricity. It met the requirement of engineering geology and attained the predictive purpose of exploratory development. It accumulated experience for the development of the area.