松藻矿区采动稳定区煤层气地面井抽采试验及应用效果

为验证采动稳定区煤层气资源评估、地面井优化设计和安全抽采等成套技术的适用性,在松藻矿区石壕煤矿进行了采动稳定区煤层气地面井抽采试验。在提出稳定区煤层气资源量评价选区基本原则的基础上,利用分源加法评估技术估算了试验点的可抽采煤层气量,进行了230 d的抽采试验,采出煤层气49.7万m³,约占估算可采气量的30%,拟合的长期最大可采气量达94万m³。试验表明:试验点采动稳定区内煤层气浓度约30%,分源加法评估结果的准确率受浓度等关键参数取值影响显著;影响采动稳定区地面井抽采效果的关键问题不是地面井筒的变形破坏,而是布井位置选择、钻井设备及工艺的选择、钻完井质量控制等因素,清水钻进工艺在钻越采动裂隙带时宜谨慎使用。

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.