苏北盆地古生界页岩气形成条件及评价

Forming conditions and evaluation of Paleozoic shale gas in North Jiangsu Basin

下扬子地区苏北盆地古生界页岩气研究尚处于起步阶段,为加强对古生界页岩气藏的认识,结合钻井现场地质剖面,研究了区域内泥页岩特征,并在此基础上对所采集样品进行地化分析,采用氯仿沥青"A"法和含气量法,计算出各层位页岩油气资源潜力,并进行最终的综合评价。认为二叠系大隆组(P_2d)和寒武系幕府山组(∈_1m)页岩有机碳含量高、吸附气含量大、脆性矿物含量高、资源潜力大,页岩气形成条件最有利,并针对这2套泥页岩发育的层位分别提出了有利勘探区,而二叠系龙潭组(P_2l)、孤峰组(P_1g)和志留系高家边组+奥陶系五峰组(S_1g+O_3w)页岩油气形成条件相对较差。这将为苏北盆地页岩油气下一步研究与勘探提供依据。

Study on Paleozoic shale gas in north Jiangsu Basin of lower Yangtze area,is still in its infancy. In order to enhance the understanding of Paleozoic shale gas reservoirs and combine with the geologic profile of drilling site,the characteristics of mud stone and shale in the area were studied,on this basis,the collected samples were conducted the geochemical analysis. The reservoir potential of shale oil and gas resources in each layer can be calculated by using chloroform bitumen "A"method and gas concentration method,and the final comprehensive evaluation can be carried out. The results showed that P_2 d of Permian Dalong formation and ∈_1 m Cambrian Mufushan formation have high organic carbon content,large adsorption gas content,high content of brittle minerals and higher resource potential,and shale gas formation conditions are the most favorable. In view of these 2 sets of horizons for the formation of mud shale,the favorable exploration area was put forward respectively. Shale oil and gas formation conditions are poor in P_2 l and P_1 g of the Permian Longtan formation and S1_g + O_3 w in the Silurian Gaojiabian formation and the Ordovician Wufeng formation. This will provide a basis for the further research and exploration of shale oil and gas in North Jiangsu Basin.