川中地区中三叠统雷口坡组三段源储特征及配置关系

通过岩心观察和薄片鉴定等资料，结合岩石物性、X射线衍射、总有机碳（TOC）含量及岩石热解和干酪根碳同位素等分析结果，对川中地区中三叠统雷口坡组三段（雷三段）的烃源岩和储层特征以及二者的配置关系进行了研究。研究结果表明：①川中地区雷三段2亚段发育一套以页岩和泥质灰岩为主的烃源岩，厚度为20～100 m，页岩平均TOC值为1.08%，最高可达4.01%，泥质灰岩平均TOC值为0.40%，有机质类型以Ⅱ₁型为主，Ⅰ型次之，处于高成熟—过成熟早期阶段，生烃潜力较好。②研究区雷三段3亚段发育一套以粉晶白云岩和砂屑白云岩为主的储层，储集空间主要为晶间（溶）孔和粒间溶孔，平均孔隙度为4.05%，平均渗透率为1.1 mD，具有低孔中渗的特征。③雷三段2亚段烃源岩与3亚段储层形成了良好的源储配置关系，可形成“下生上储”、“自生自储”型油气藏，裂缝系统既为油气运移通道，也是重要的储集空间，上覆雷四段膏盐岩和须家河组一段泥岩均为有效盖层。

Source-reservoir characteristics and configuration of the third member of Middle Triassic Leikoupo Formation in central Sichuan Basin

Based on the data of core observation and thin section identification,combined with the analysis results of rock physical properties,X-ray diffraction,total organic carbon(TOC)content,rock pyrolysis and kerogen carbon isotope,the characteristics of source rocks and reservoirs of the third member of Middle Triassic Leikoupo Formation(T₂ l₃)in the Central Sichuan Basin and their configuration relationship were systematically studied. The results show that:(1)There is a set of hydrocarbon source rocks mainly composed of shale and marl developed in the second sub-member of T₂l₃(T₂l₃²)in Central Sichuan Basin,with a thickness of 20-100 m. The average TOC value of shale is 1.08%,up to 4.01%,and the average TOC value of marl is 0.40%. The organic matters are mainly type Ⅱ₁,followed by type Ⅰ,which are in the early stage of high maturity to over maturity,and have good hydrocarbon generation potential.(2)A set of reservoir mainly composed of silty dolomite and sandy dolomite is developed in the third sub-member of T₂ l₃(T₂ l₃³). The reservoir space is mainly composed of intercrystalline(dissolved)pores and intergranular dissolved pores,with an average porosity of 4.05% and an average permeability of 1.1 mD. It has the characteristics of low porosity and medium permeability.(3)The source rocks of T₂ l₃² have a good source-reservoir configuration relationship with the reservoirs of T₂ l₃³,which can form the hydrocarbon accumulation model of "lower generation and upper accumulation" and "self-generation and self-accumulation". The fracture system is not only an oil and gas migration channel,but also an important reservoir space. The overlying gypsum salt rocks of the fourth member of Leikoupo Formation and the mudstone of the first member of Xujiahe Formation are effective caprocks.