川东北五宝场外围沙溪庙组二段沉积储层特征研究

Study on Sedimentary Reservoir Characteristics of the Second Member of Shaximiao Formation in Wubaochang, Northeast Sichuan

摘要: 川东北五宝场外围沙二段具备较好的勘探潜力，但该区沙二段沉积储层研究不足制约了该区油气高效开发。为了深化对该区沙溪庙二段沉积储层特征的认识，指导下一步勘探部署，综合利用野外调研、测录井数据、岩心观察、薄片鉴定和分析化验资料，对研究区沙二段沉积相及储层发育进行系统研究。结果表明，1) 五宝场外围地区沙二段第一亚段主要发育曲流河及三角洲前缘亚相，沙二段第二亚段、三亚段主要发育曲流河–三角洲平原亚相，总体呈现水体较浅、古地形相对比较平缓的沉积特征；2) 储层岩石类型主要以长石岩屑砂岩为主，其次为岩屑砂岩，储集空间类型分为孔隙和裂缝两大类，总体表现为低孔低渗–特低渗储层特点；3) 沙二段储层受到沉积作用、成岩作用和构造作用的影响，相控因素和构造因素影响最大。结论认为，该研究成果可以为研究区沙二段下一步油气勘探部署提供依据。

Abstract: The second member of Sha-2 Formation outside Wubaochang in northeast Sichuan has good exploration potential, but the lack of sedimentary reservoir research in this area restricts the efficient oil and gas development in this area. In order to deepen the understanding of the sedimentary reservoir characteristics of the second member of Shaximiao in this area and guide the next exploration and deployment, comprehensive use of field investigation, well logging data, core observation, thin section identification and analysis and laboratory data to systematically study the sedimentary facies and reservoir development of the second member of Shaximiao in the study area. The results show that: 1) Meandering river and delta front subfacies are mainly developed in the first submember of Sha-2 Member in the periphery of Wubaochang, while meandering river-delta plain subfacies are mainly developed in the second submember of Sha-2 Member and Sanya Member. 2) The reservoir rock types are mainly feldspar lithic sandstone, followed by lithic sandstone, and the reservoir space types are divided into pores and fractures, showing the characteristics of low porosity and low permeability reservoir. 3) The reservoir of the second member of Sha-2 is influenced by sedimentation, diagenesis and tectonics, and the phase-controlled factors and tectonic factors have the greatest influence. It is concluded that the research results can provide a basis for further oil and gas exploration and deployment in the second member of Sha-2 in the study area.