The status quo and future development of gas drilling technology in the Sichuan gas field

The bottle-neck points of Sichuan drilling technology are low ROP,lost circulations,reservoir damage resulted from complicated geologic conditions.In recent years,gas drilling technology has been studied and tested;it shows good results,exhibiting technical advantages and bright development prospects.Up to now,we have developed technical specifications for gas drilling,and a series of technologies including straight gas drilling,mist drilling,foam drilling,fast deflection-minimized gas drilling,gas/liquid conversion,effective fluid drainage,gas coring,gas drilling equipment and tools,horizontal drilling with gas,and measures to solve gas drilling problems,etc.Field application shows that those technologies play important roles in ROP improvement,control of lost circulations,discovery and protection of reservoirs.Gas drilling is still a new technology in China,and it is recommended that study be conducted on the mechanism of BOP erosion to develop special well control equipment for gas drilling,and a set of data acquisition and remote control system be set up to improve reliability and safety of gas drilling.