黔北武陵褶皱区安场向斜页岩气储层特征分析

Analysis of Shale Gas Reservoir Characteristics of Anchang Syncline in Wuling Fold Area of Northern Guizhou

摘要: 综合地质、岩心、测井等多种资料，从岩性、电性、物性、地化特征、可压裂性分析等方面对黔北武陵褶皱区安场向斜页岩气储层特性进行了分析。结果显示研究区龙马溪组一段–五峰组黑色深水陆棚相碳质页岩矿物组成以石英、粘土矿物、长石、碳酸盐岩、黄铁矿为主，具有高自然伽马、高铀、低密度、高声波时差、中高电阻率典型页岩气储层测井特征，有机质丰富，以腐泥型干酪根(I型)为主，岩心有机碳含量以≥4.0%为主，平均孔隙度以≥3.0%为主，进入过成熟中期演化阶段，以生成干气为主，脆性矿物含量高，可压裂性较好，整体表现出“薄而富”特征。综合认为安场向斜龙一段–五峰组页岩气储层具有较好的页岩气资源勘探开发潜力。

Abstract: The characteristics of Anchang syncline shale gas reservoir in Wuling fold area of Northern Guizhou are analyzed from the aspects of lithology, electrical property, physical property, geochemical characteristics and fracturing analysis by combining geological, core, logging and other data. The results show that the black deep-water continental shelf carbonaceous shale in the first member of Longmaxi formation and Wufeng formation in the study area is mainly composed of quartz, clay minerals, feldspar, carbonate rock and pyrite. It has the logging characteristics of typical shale gas reservoirs with high natural gamma, high uranium, low density, high acoustic time difference, medium and high resistivity. It is rich in organic matter, mainly sapropel kerogen (type I), the organic carbon content of the core is mainly ≥4.0%, and the average porosity is mainly ≥3.0%. It has entered the medium-term evolution stage of over maturity, mainly generating dry gas. It has high content of brittle minerals and good fracturing performance, showing the characteristics of “thin and rich” as a whole. It is comprehensively considered that the shale gas reservoir of Longyi member Wufeng Formation of Anchang syncline has good exploration and development potential of shale gas resources.