Study and application on compound potassium salt polymer drilling fluid

Jinqiu block in Sichuan is rich in deep-basin gas, but has high pressure coefficient, active gas layer, and serious CO2 invasion. The upper thick purple shale was easy to hydrate mud-making formation and the logging was required to be not affected by slurry. These are high requirements for drilling fluid. Based on the existing technical difficulties of drilling fluid, the strong inhibition of potassium salt polymer drilling fluid system was optimized. This system uses the preferred compound potassium salt as main inhibitors. The advantages of this system are strong inhibition, good temperature resistance ability, anti-pollution ability, and high density of 2.20 -2.30g/cm3, which can meet the drilling requirements in the region.