Study and Application of Ultra-deep Well Drilling in Well Yuanba-1

To implement the sustainable development of oil and gas resources, exploration of oil and gas was focused on deep wells and ultra- deep wells in western and southern China. But at the current, deep well drilling techniques could not completely need the exploration and development. Therefore, studies on air drilling techniques, composite drilling techniques, prevention techniques against wear of casing, optimization of drilling fluid and cementing techniques are conducted and applied to deep Well Yuanba-1. The total drilling depth of this well is 7170.71 m and the drilling period is 279.17 days. And the wellbore quality and the cement job quality are high. A number of technological breakthroughs and high regional drilling index are acquired.