Research and application of frequency adjustable pulse jet generating tool to improve ROP

Improving ROP is a long-term problem for tight gas reservoir drilling. Sulige gas field development plan is restricted significantly by the high cost of drilling and the difficulty of improving ROP for tight gas reservoirs in west Sulige gas field. The frequency adjustable pulse jet generating tool is been developed to improve ROP of drilling the substratum of middle-deep wells in west Sulige gas field. The tool converts the continuous flow of drilling fluid into pulse jet flow through the control valve which is driven by some turbine, to improve downhole flowing field and enhance breaking force of jet, so it can improve hydraulic rock breaking efficiency and downhole cleaning ability furthest. The indoor experiment and field test results show that the tool can work for more than 120 hours, and improve ROP by more than 20%. So, the frequency adjustable pulse jet generating tool, as a technique that can improve ROP effectively in substratum middle-deep well, has extensive application potential in Changqing tight gas field.