高丰度煤层气富集区地球物理识别

为预测煤层气富集区,通过地震反演和地震属性分析,获得了煤层含气量、地质构造、煤层厚度、煤层结构、煤层顶、底板岩性和裂隙等地震地质参数,基于地球物理信息融合方法对煤层气富集区进行了预测。研究结果表明:随着埋藏深度增加,煤层厚度增加,煤层含气量呈增加趋势;向斜轴部隆起带煤层含气量大,背斜轴部凹陷区煤层含气量相对较多;构造煤分布区一般煤层气较富集;煤层直接顶底板为泥岩,则煤层含气量一般较高;裂隙的存在会对煤层气含量有一定影响。研究认为,煤层埋深、煤层厚度、结构、构造和顶底板岩性等参数是控制研究区煤层气富集的主要地震地质因素,基于地球物理信息融合对煤层气富集区进行预测,可以避免单一地震地质因素预测的局限性,有助于提高预测精度。

High abundance coalbed methane rich region geophysical identification

In order to predict the coalbed methane(CBM) rich region，CBM content，geologic structure，coal seam thickness，coal seam texture，roof and floor lithology，fracture as well as other seismic and geologic parameters were obtained through seismic inversion and seismic attribute analysis，and the prediction for CBM rich region was made based on the geophysical information fusion methods.The research results indicate that the CBM content increases with the increase of burial depth and the coal seam thickness；the CBM content is high in the uplift zones near the syncline axis，and also is relatively high in the depression zones near the anticline axis；zones where tectonically deformed coals distribute are usually very rich in CBM；the CBM content is often relatively high where the immediate roof and floor of the coal seam are mudstones；the existence of fractures has some effects on the CBM content.It can be concluded from the research that the burial depth，coal seam thickness，structure，texture and roof and floor lithology，etc.are the major seismic and geologic factors that control the enrichment of CBM in the zone of interest，and the prediction for CBM rich region based on the geophysical information fusion methods can avoid the limitations of predictions with single seismic geologic factor，and will improve the accuracy of the prediction.