Effects of stress field in bottom hole on borehole deviation during gas drilling

In order to explore the effect of ambient pressure on jet flow field in deep well and ultra-deep well, a physical model for flow field of confined water jet at bottom hole was established.

When the pumping well runs normally, self-excited pressure wave can be generated at bottom hole by means of wave generator.

The measurement and analysis of craters and bottom-hole pattern is an important link of drilling test and a key means of studying rock-breaking mechanism and valuating rock-breaking efficiency.

Numerical calculation and experimental study of drilling shaft bottom in special thick alluvium;

Optimizing schemes of drilling shaft bottom in special thick alluvium;