鄂东气田煤层气储层测井综合评价方法研究

Comprehensive Log Evaluation for Coalbed Methane Reservoir in Eastern Block of Ordos Basin

影响煤层气储层性能的参数众多。从煤储层地质特征、物性特征和储集特征出发,优选出能够充分反映煤层气储层优质与否并且利用测井资料易于求取的6个指标:煤岩性质和结构、裂缝发育程度、裂缝孔隙度、渗透率、煤层气含量和有效厚度。针对鄂东气田煤层气储层非均质性强,煤层气储层综合评价中存在储层参数的随机性、模糊性等诸多问题,给出煤层气储层模糊综合评价模型。利用测井资料和实际煤岩心室内分析资料,构建用于煤层气储层测井综合评价的模糊评判集,并基于此模糊评判集,采用模糊综合评价模型对工区内重点井进行了模糊综合评判。该评价结果与室内测试分析结果具有较好的一致性。

It has an important significance for coalbed methane exploration and development that accurately and comprehensively evaluating the coalbed methane reservoir with log data. In view of many parameters affecting the performance of coalbed methane reservoir, as well as geological features, physical properties and characteristics of the coal reservoir, six indexes are selected to reflect the CBM reservoir quality. They are coal petrography index, fracture growth index, fracture porosity index, permeability index, coalbed methane content index and effective thickness index. Due to the strong heterogeneity of coalbed methane reservoirs of gas field in eastern block of Ordos basin, the reservoir parameters are often random and fuzzy in the comprehensive evaluation of the coalbed methane reservoir, therefore we suggest a fuzzy comprehensive evaluation model. Using log data which have abundant geological information of coalbed methane reservoir and the laboratory analysis data of actual coal core, the fuzzy evaluation set is established to evaluate the coalbed methane reservoir, based on which the fuzzy comprehensive evaluation model is carried out for the work area. The comprehensive log evaluation result has a good consistency with laboratory test and analysis result.