峰峰煤田磁西一号勘查区煤层气赋存特征与开发建议

Existence features and exploration suggestions of CBM in Cixi No. 1 Exploration Area of Fengfeng Coalfield

为了明确磁西一号勘查区煤层气赋存的特征与开发的可行性，在矿区煤田地质特征研究的基础上，分析了影响煤层气聚集的各地质因素，通过施工煤层气参数孔，获取2，4煤层的孔隙度、渗透率等储层参数。根据等温吸附实验与含气性测试可知，研究区CH4含量为8．98～12．01m3／t，煤层含气饱和度在50％左右；勘查区内断层发育，破坏了煤层的完整性而难于形成较大的降压漏斗；尤其是在煤层顶底板附近出现断层时，2，4煤层与奥灰含水层形成水力联系，储层压力难于降到煤层气临界解吸压力以下，难于形成工业气流。从现阶段的工艺技术条件和经济性考虑，研究区近期不适宜进行煤层气的地面开发，而应做好煤层气的并下抽排工作，做到煤与煤层气资源的综合开发利用。

To probe the occurrence characteristics and to clarify the development feasibility of Coalbed Meth- ane （CBM） in Cixi No. 1 Exploration. The influence of various geological factors of CBM accumulation were got based on analysis of geological characteristics of coalfield. The reservoir parameters of 2, 4 coal seam porosity, permeability obtained by construction of CBM parameter hole. The isothermal adsorption experiment and gas testing show that CH4 content is 8.98 - 12. 01 m3/t, and gas bearing saturation is around 50%. It is difficult to form a larger pressure drop funnel in the exploration area because of the coal seam integrity destroyed by faults. Especially 2, 4 coal seams and the Ordovician limestone aquifer connected each other when the fault near to the coal seam roof and floor, and it is difficult to form industrial gas flow because the reservoir pressure is difficult to reduce to below the critical desorption pressure of CBM. It is not suitable for CBM development from the present technical conditions and economic considerations, so underground CBM drainage is a good method for comprehensive development and utilization of coal and CBM resources.