Study on solid-liquid separation of waste water-based drilling mud—A case study on X well in Pengshen, Sichuan province

Author of the article:ZHAN Feng1,2, CHENG Quan1, LIU Huimin3, SONG Guangming1, ZHU Lin 3, SUN Yong1, ZHAO Zhiyue1

Author's Workplace：1. Chengdu Dayou Petroleum Drilling and Production Engineering Co., Ltd., Chengdu, Sichuan, 610051, China; 2. CNPC Chuanqing Drilling Engineering Company Limited West Sichuan Drilling Company, Chengdu, Sichuan, 610051, China; 3. School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan, 610500, China

Key Words： Water-based drilling mud; Chemical strengthening; Solid-liquid separation; Mud treatment agent

Abstract：The efficient and harmless treatment of waste water-based drilling mud generated by drilling platforms is essential to the production process. An experimental study is conducted on chemically enhanced solid-liquid separation of water-based drilling mud produced in a well drilling operation in Pengshen, Sichuan. The effects of gel breaker with single reagent, two or three reagents on solid-liquid separation of mud are systematically discussed through experimental research. The results showed that in the single factor experiment, the solid-liquid separation effect of adding quicklime alone is the best, with a dosage of 0.8 g/50 mL; in the twofactor experiment of the synergistic effect of the two reagents, the dosage of FeSO4 and CaO should be controlled at 0.6 g/50 mL; in the orthogonal experiment of the three reagents, the order of causality that affects the separation effect is FeSO4>CaO>PAC chloride. It is concluded that under the optimal conditions, the ratio of PAC, FeSO4 and CaO is 0.3∶0.4∶0.15, and the density of the clear liquid obtained is 1.038 g/mL. The study can provide technical support for the efficient and harmless treatment of water water-based drilling mud produced by the drilling platform.