The Development and Field Testing of Low Viscosity and Low Gel Strength Polymer Collapse-Resistant Water-Based Drilling Fluid in the Fuling Shale Gas Field

During drilling in Jiaoshiba Block of Fuling Area, problems were encountered in the second spudding as high viscosity of drilling fluid, high drag, large torque and that WOB could not be transmitted to the bit during directional drilling. To address these problems, a kind of polymer collapse-resistant water-based drilling fluid with low viscosity and low gel strength was developed. Laboratory tests showed that the water-based drilling fluid demonstrated good inhibition, lubricity, plugging properties and contamination resistance, high temperature resistance up to 100℃. It was successfully implemented in the second-spudding in the Jiaoshiba Block, and the problems that caused by formation hydration, including high viscosity and high density as well as ineffective transmission of WOB were solved effectively, so as to keep normal drilling, shorten drilling cycle time and improve drilling efficiency.