Study and Application of Formation Water Production and Borehole Wall Stability Prediction Technologies in Daqing Gas/Foam Drilling

The practices have shown that the premise for successful implementation of gas drilling is stable borehole wall, formation<br>containing less water or no water, not high pressure formation and clear reservoir bed relation, etc. Therefore, accurately<br>evaluating borehole wall stability, predicting formation water production and selecting reasonable well intervals for gas<br>drilling to effectively prevent occurrence of complex conditions such as blocking, sticking and fracture of drilling tools, etc.<br>caused by formation water production and borehole wall instability are the keys for success of gas drilling.