泌阳凹陷页岩油储层孔隙发育特征与测井定量评价

Pore development characteristics and logging quantitative evaluation of shale oil reservoirs in Biyang Depression

利用岩石薄片、扫描电镜、高分辨率扫描电镜、氩离子抛光高分辨率扫描电镜、比表面实验等分析技术,对泌阳凹陷页岩孔隙进行了量化表征。泌阳凹陷页岩粒间孔隙发育相对较少,尺寸几百纳米至几微米;黏土矿物晶间孔尺寸多位于几十纳米到几百纳米、重结晶晶间孔孔径在1~3μm;溶蚀孔隙发育尺寸与溶蚀的程度有关,尺寸相对较大,多在几百纳米以上;有机质孔隙以条带状的边缘孔隙发育为主,尺寸变化较大。泌阳凹陷页岩有机质和黏土矿物与吸附油含量正相关,其分布产状主要呈分散状、层状、纹层状等状态,而游离油分布状态主要受其赋存的储集空间类型的影响,在构造缝、层间缝及基质孔隙内较丰富。在此认识的基础上,利用常规测井曲线建立了泌阳凹陷页岩孔隙定量评价模型,明确了泌阳凹陷脆性矿物、黏土和有机质三者单位质量内的微孔隙体积值,为下步定量评价页岩储层孔隙提供了依据。

By using rock thin section,scanning electron microscopy,high resolution scanning electron microscopy,high-resolution argon ion polishing scanning electron microscopy,surface area analysis technology experiments,this paper quantitatively characterizes the porosity of shale in the Biyang Depression.The intergranular pores of clay minerals are relatively small,ranging in size from a few hundred nanometers to a few hundred nanometers.The size of the intercrystalline pores of clay minerals is mostly between tens of nanometers to hundreds of nanometers,and the pore diameters of recrystallized intercrystalline pores are between 1~3μm.The size of dissolution pore development is related to the degree of dissolution,and the size is relatively large,mostly above several hundred nanometers.And the organic matter pores are mainly developed as striped edge pores,with large changes in size.The organic matter and clay minerals of shale in Biyang Depression are positively correlated with the content of the adsorbed oil,and their distribution is mainly distributed,layered and laminar.While the distribution of free oil is mainly influenced by the type of storage space in which it is stored,and it is abundant in structural joints,interlayer joints and matrix pores.On the basis of this understanding,this paper uses conventional logging curves to establish a quantitative evaluation model for shale pores in Biyang Depression,and clarifies the micropore volume values of brittle minerals,clays and organic matter in Biyang Depression,which provide a basis for the next quantitative evaluation of shale reservoir pores.