沁水盆地和顺区块基于地震多属性分析的煤层含气量预测

煤层含气量是煤层气勘探选区评价和开发部署必不可少的重要资料。煤层含气量及其平面分布特征的准确预测对煤层气勘探新区更加至关重要。通过地震、测井和测试数据的综合分析，验证并优选出了与煤层含气量相关程度高的地震属性。消除埋深影响的地震吸收衰减属性与含气量呈明显正相关性；构造(正)曲率与含气量呈负相关性；密度属性与含气量呈明显负相关性。地震AVO分析给出的碳氢指数(P×G)属性和拟泊松比属性与煤层气富集程度相关性较好，可以作为煤层含气量预测的重要参数。针对沁水盆地北部和顺区块，基于地震多属性分析的思路，建立了井点处地震属性和地质参数与实测含气量之间的多元线性回归方程。将该方程应用于非井点处的地震叠前反演属性数据体，实现了研究区太原组15号煤层含气量的定量预测。

 Gas content is the essential data for coalbed methane (CBM) areas selection and evaluation as well as development deployment.Accurate prediction of gas content and its distribution is even crucial for new exploration areas of CBM.On the comprehensive analysis of seismic data,logging and test data,seismic attributes highly related with the gas content of coalbed methane are verified and preferred.Seismic wave absorption attenuation attributes,eliminating the influence of buried depth,have significantly positive correlation with gas content.Tectonic (positive) curvature shows negative correlation with gas content.Density attribute has significantly negative correlation with gas content.The correlations of hydrocarbon index (P×G) provided by seismic AVO analysis and pseudo Poissons ratio with the enrichment of coalbed methane are fairly good,which can be used to predict gas content.In the way of the seismic multi-attributes analysis,multiple linear regression equations among seismic attributes,geological parametres and gas contents measured from CBM wells are established for Heshun Block in northern Qinshui Basin.The equation is applied to seismic prestack inversion attributes volume in the area,to the exclusion of CBM wells,and gas content of 15th coalseam in Taiyuan group of this area is quantitatively predicted.

国家科技重大专项“物探技术在煤层气勘探开发中的应用”(2011ZX05035006)资助。