Study on the variation law of directional drilling extraction characteristics in response to hole layout parameters

In order to ensure the rationality of directional drilling layout and further improve the gas extraction effect, the variation law of directional drilling extraction characteristics in response to hole layout parameters was studied by numerical simulation and field industrial test. The results show that: the extraction effect of directional long drilling shows a decreasing trend along the axis of the hole, and the overall influence range is rounded. In the case of a certain extraction negative pressure, directional drilling with two branches has a better extraction effect, the gas content reduction value is larger in the control range, and the comprehensive cost performance ratio of drilling arrangement is higher. The residual gas content in drilling control area coupled with the spatial position in the effective influence area presents a double exponential variation law. The research results can provide reference for the selection of design parameters of directional drilling and the pre-evaluation of extraction effect.