东营凹陷深层溶蚀孔隙的多重介质成因机理和动力机制

Cause of Formation and Dynamic Mechanisms in Multiply Medium of Dissolved Pores in Deep Formation of Dongying Sag

通过岩心观察、薄片鉴定、扫描电镜观察、流体包裹体分析、粘土矿物分析与Ro测试等手段,结合地层压力史、构造发育史、有机质成烃史等研究成果,以揭示东营凹陷下第三系深部碎屑岩储层溶蚀孔隙的成因机理和动力机制为目的开展工作,得到以下认识:该凹陷深层溶蚀孔隙具有多重溶解机理,主要是有机酸溶解作用、无机酸溶解作用、硫酸盐热化学氧化还原反应和油田水引起的溶解作用等酸性介质溶解机理和以石英为主要溶蚀对象的碱性介质溶解机理;溶解作用的动力机制包括循环热对流、断裂活动引起大气淡水淋滤和超压泄露。

The cause of formation and dynamical mechanisms in multi-ply medium of dissolved pores in deep formation of Dongying sag were revealed by those means such as core observation, thin-section analysis, scan electricity microscope observation, inclusion analysis and Ro test, etc and combining histories of stratum pressure, tectonic development and organic maturation. It was recognized that the reservoir in deep formation has multi-ply dissolving mechanisms. They are acidity medium dissolving mechanism and alkalescence medium dissolving mechanism. The former includes organic acid dissolution, abio-acid dissolution and dissolution caused by sulfate thermochemistry oxidation-reductive reaction and oil field fluid. The later gives priority to quartz dissolution. 6 kinds of methods to recognize quartz dissolution are put forward. The dynamical mechanisms of dissolution include cyclic thermal convection, atmosphere water infiltrating through active faults and exceed pressure leak near the faults.