川东北地区须家河组沉积相与储层特征

川东北地区上三叠统须家河组地层具有较大的勘探开发潜力，但长久以来对该地层的研究甚少，沉积相和储层研究已成为川东北地区须家河组油气开发急需解决的问题之一。通过岩心观察、薄片鉴定及样品分析测试工作，根据岩石特征及测井相分析方法，对川东北地区须家河组沉积相类型、储集空间类型、储层物性特征以及影响储层的因素进行了分析。结果表明，研究区须家河组主要发育辫状河三角洲相沉积，可进一步划分为三角洲平原、三角洲前缘及前三角洲3类亚相；储层低孔低渗，主要孔隙空间为次生孔隙和裂缝，裂缝-孔隙型是主要的储集类型；储层储集性能主要受沉积微相和成岩作用控制。

Northeast Sichuan Gas Field, PetroChina Southwest Oil & Gasfield Company, Dazhou 635000, China

The Upper Triassic Xujiahe formation in the northeastern Sichuan basin has relatively large exploration and development potential, but it has not been studied in detail. Study on sedimentary facies and reservoirs have become one of the key issues that need to be solved urgently concerning oil and gas recovery from the Xujiahe formation in the northeastern Sichuan basin. Based on core observation, thin section analysis and sample testing results, the types of sedimentary facies, types of reservoir spaces, poroperm characteristics and the factors influencing the reservoirs are recognized through rock features and electrofacies analysis. The results show that the Xujiahe formation in the study area is dominated by deposits of braided river delta facies, which can be further divided into 3 subfacies including delta plain, delta front and predelta. The reservoirs have low porosity and low permeability and their pore spaces are dominated by secondary pores and fractures. The reservoirs are mainly of fracture pore types and their poroperm characteristics are controlled primarily by sedimentary microfacies and diagenesis.