天津静海含煤区无井式煤炭地下气化选址地质评价模型

Geological evaluation model for site selection of underground coal gasification without well in Jinghai coal-bearing area, Tianjin, China

地质条件对煤炭地下气化选址起着重要作用。运用二级模糊综合评判法,从勘探情况、煤层特征、煤质特征、水文条件4个影响因素入手,构建了天津静海含煤区无井式煤炭地下气化地质评价模型,并通过质量守恒物料衡算与室内模拟实验结果对比验证了模型的适用性。研究认为:影响无井式煤炭地下气化的地质条件所占权重依次为勘探情况>煤层特征>水文条件>煤质特征,综合得分高于70的区域为无井式煤炭地下气化适合区,60~70分为比较适合区,低于60分为不适合区。天津静海含煤区5号煤层综合评分为78.89分,为无井式煤炭地下气化适合区,扣分项主要来自于埋深、CO2反应活性(900℃)和黏结性。物料衡算所得煤气组分与室内模拟实验所得煤气组分相对误差均在允许误差15%范围内,有用组分(H2+CO+CH4)相对误差为2.63%,证明了所建模型的适用性,对后期生产规模设计和现场生产具有一定的指导意义。

Based on the 4 factors such as exploration status,coal seam,coal quality and hydrological conditions,using the secondary fuzzy comprehensive evaluation method,the geological evaluation model without well was built.In order to verify the applicability of the model,the material balance by law of conservation of mass was carried out and the results compared with the test results of indoor model was got.This research suggests that the weight of geological conditions affecting underground coal gasification without well is exploration status>condi-tions of coal seam>hydrological conditions>coal quality,the area with comprehensive score higher than 70 is the more suitable area,the area with score 60~70 is the suitable area and the area with score less than 60 is the unsuit-able area.In the Jinghai coal-bearing area,the comprehensive score of the No.5 coal seam is 78.89 which belongs to more suitable area of underground coal gasification without well,and the buried depth,CO2 reactivity(900℃),the poor cohesiveness and suitability made the score deducted.The gas components obtained from material balance and laboratory simulation tests have the relative error within 15%of the allowable error,and the relative error of useful components(H2+CO+CH4)is 2.63%,which not only proves the applicability of the system,but also has certain guiding significance for the later production scale design and field production.