瞬变电磁法在采空区煤层气抽采井选址中的应用研究

Application of Transient Electromagnetic Method in Site Selection of Coalbed Methane Extraction Well in Goaf

为给采空区煤层气抽采井选址提供依据,降低废孔率,采用瞬变电磁法对采空区地质资料不明区域进行试验探测。研究了瞬变电磁法在沁水煤田采空区及积水区探测中的适用性,对瞬变电磁发射频率、发射线框大小、发射电流进行了不同参数比对试验;通过对比不同网度条件下的探测成果,在勘查区网度选择20 m×20 m时探测精度较高且经济合理;瞬变电磁法可较精确地圈定采空积水区域,在抽采井选址中提前避开,从而提高钻井抽采成功率。

In order to provide basis for site selection of CBM extraction wells in goaf and reduce waste hole rate, transient electromagnetic method was used to test and detect the unknown area of geological data in goaf. The applicability of TEM in detecting goaf and water pool in Qinshui coalfield is studied.Different parameter comparison tests are carried out for transient electromagnetic emission frequency,emission wire frame size and emission current. By comparing the detection results under different network degree conditions, the detection accuracy at 20 m ×20 m selected in the exploration area network degree is relatively high and economic and reasonable.Transient electromagnetic method can accurately delineate the area of drainage water and avoid it in advance in the site selection of drainage well, thus improving the success rate of drilling and drainage.