山西晋城采煤扰动区地面煤层气井抽采效果地质分析  

Geological Analysis of Drainage Effects on CBM Wells in the Coal-Mining-Disturbed Area of Jincheng, Shanxi Province

作　　者：田永东[1] 张遂安[1] 张典坤 赵祉友 赵小山 

机构地区：[1]中国石油大学(北京),北京102249 [2]山西蓝焰煤层气集团有限责任公司,晋城048000

出　　处：《高校地质学报》2012年第3期563-567,共5页Geological Journal of China Universities

基　　金：国家科技重大专项(2011ZX05063)

摘　　要：从地质研究角度,分析了晋城矿区采煤扰动区三口地面煤层气井的抽采效果。结果表明,采动井布置需要综合考虑原位地质条件和采动后的矿井地质条件,煤层含气量较高、开放性采动裂隙发育、岩层移动相对较弱的地段有利于采动井的井筒稳定和持续高产。采动井抽采过程一般经历三个阶段,即采煤工作面未达井筒阶段、采煤工作面靠近井筒阶段和采煤工作面远离井筒阶段,各阶段抽采量、浓度均表现出不同的特征。采动井的井身结构是影响抽采效果的重要工程因素,二开井段套管不固井的方式可以有效保护井身结构的完整性,但井筒体系密闭性不好,受此影响导致抽采甲烷浓度偏低;三开井段采用裸眼完井方式能够有效提高抽采流量及甲烷浓度,但不利于井筒保持稳定。Drainage effect of three coalbed methane （CBM） ground wells at a coal-mining-disturbed area of the Jincheng mining district was analyzed in the light of the geological research, which provides a new reference for the CBM ground extraction in China. Results showed that the geological conditions in-situ and after coal mining shoud be comprehensively investigated for the well-site design of the disturbed area. It was found that the higher CBM content, much developed open mining fracture and weaker strata movement are beneficial to the borehole stability and sustainable high production. The whole process of the well drainag went through three stages including borehole before coalface, borchole near coalface, and borehole after coalface. The production and concentration of CBM were different at each stage. Casing program of the wells is an important engineering factor that control drainage effects. Non-cementing pattern can protect effectively the integrity of the casing program in the second section but the methane concentration is low due to poor sealing property of the borehole system. Openhole completion pattern can improve effectively the extraction rate and methane concentration in the third section but is not conducive to the borehole stability.

关 键 词：晋城 采动井 地质条件 抽采效果 

分 类 号：P618.11[天文地球—矿床学]