论文部分内容阅读
煤层气赋存受多种因素共同控制,地下水便是其中之一。地下水和煤层气可共生、可伴生,煤层气的形成、运移、富集以及资源评价、开采各个方面与地下水及水文地质条件息息相关。水文地质条件对煤层气赋存的影响主要是水动力场和水化学。水动力对煤层气的影响主要是水力封堵控气作用和水力封闭控气作用,水化学对煤层气的影响因素主要包括地下水的矿化度、矿物成分、矿物离子组分﹑同位素种类、p H值等。通过对地下水化学特征的分析,阐明了煤层气的运移、富集成藏规律。按煤层气开采时段分析了对地下水的影响:施工期对地下水的影响主要存在于钻井施工环节,如引发地震使地下水浑浊、破坏含水层结构、钻井液泄漏污染地下水以及大量消耗水资源;运营期对地下水的影响主要是甲烷泄漏污染地下水、返排液污染地下水以及地下水水位和流场改变。
CBM is controlled by many factors and groundwater is one of them. Groundwater and CBM can be symbiotic, can be associated, the formation of CBM, migration, enrichment and resource evaluation, mining and other aspects of groundwater and hydrogeological conditions are closely related. The impact of hydrogeological conditions on the occurrence of coalbed methane is mainly hydrodynamic field and water chemistry. The influence of hydrodynamics on coalbed methane is mainly controlled by hydraulic plugging and controlled by water. The factors that influence water chemistry on coalbed methane include groundwater salinity, mineral components, mineral ion components and isotopes, p H value and so on. Through the analysis of chemical characteristics of groundwater, the migration and enrichment of coalbed methane are clarified. According to the period of CBM exploitation, the impact on groundwater is analyzed: the impact on groundwater during the construction period is mainly in the drilling construction stage, such as causing muddy groundwater, destroying aquifer structure, drilling fluid leakage and polluting groundwater and consuming a large amount of water resources during the earthquake; The main impacts on groundwater are groundwater polluted by methane leaks, groundwater polluted by return fluids and changes in groundwater level and flow field.