煤层气开发项目的高风险制约着我国煤层气产业的发展,为此,通过对煤层气开发风险因素的分析,基于煤层气开发特征构建由7个一级指标和34个二级指标构成的风险评价体系。运用离差平方和优化组合熵值法和三角模糊数法所得权重确定指标最佳权重,建立煤层气开发风险评价模型。最后,以沁水盆地南部柿庄南区块煤层气井为例进行实证评价,结果显示地质资源因素对该地区煤层气开发影响最大,其中渗透率的影响最为显著。研究表明:模型能优化主观评价和客观评价的赋权比重,最大化的减少主观因素对评价结果的影响,能客观合理的表达多指标间的对比差异,对煤层气开发风险进行可靠的定量化评价。为煤层气开发风险的控制和规避提供科学的理论依据。
The high risk of coalbed methane( CBM) development project restricts the development of CBM industry in China. Through the analysis on risk factors of CBM development,an risk assessment system consisted of 7 first-grade indexes and 34 second-grade indexes was established based on the characteristics of CBM development. The optimal weight of indexes was determined based on the weights obtained by combining entropy value method with triangular fuzzy number method and optimized by sum of squares of deviations,and a risk evaluation model of CBM development was constructed. Finally,the practical case assessment was conducted by taking the CBD well in south block of Shizhuang in southern Qinshui basin. The results showed that the geological resource factor had the largest influence on CBM development in this region,among which the influence of permeability was the most obvious. It showed that the model can optimize the weighting proportion of subjective and objective assessment,reduce the influence of subjective factors on assessment results to the most,represent the contrast difference of multiple indexes objectively and reasonably,and carry out reliable quantification assessment of CBM development risk. It can provide scientific theoretical basis for the control and avoidance of CBM development risk.