Drainage Test of CBM Ground Well in Mining Stability Area of Songzao Coal Mine

In order to verify the applicability of CBM resources assessment, optimization design of ground wells and safety extraction techniques in mining stability area, a drainage test of CBM ground well in mining stability area was implemented in Shihao Coal Mine of Songzao. On the basis of putting forward the basic principles of evaluating the constituency, the amount of CBM in the test area was estimated with divided resource overlay evaluation model, and then the 230 days pumping test was carried out,the gas output was 497 thousand m³, which accounted for about 30% of the max recoverable. The max output gas of the long term fitting was 940 thousand m³. The test showed that the gas concentration in SCMA region is about 30%, and the accuracy of the source added evaluation result is significantly influenced by the key parameters such as concentration; the key factors that affect the extraction effect of ground well in SCMA region were not the failure of wellbore, but the well location selection, drilling equipment and technology selection, drilling quality control factors, and the clean water drilling should be used carefully when drilling through fractured zone.