Hole stability technologies for bore hole pretreatment after gas drilling

The cause of wall collapse after gas drilling in the northeastern area of Sichuan is analyzed, the vibration mechanism of the wettability properties of surface of rock in the formation affected by hydrophobic treatment agent is discussed, the optimization and lab experimental study of wettability reversing agents are conducted. After applying the agents to multiple wells in the northeastern area of Sichuan, the hole gets more stable, and the time of gas-liquid conversion is shortened. And the gas-liquid conversion well stability technology appropriate for the geological characteristics of the terrestrial formation of northeastern Sichuan is primarily developed. Test shows that the bore hole pretreatment technology can improve the hole stability during the process of gas-liquid conversion, preventing the complicated downhole conditions caused by collapse of mud shale formations caused by rapid water absorption.