渤海海域沙垒田凸起西北部奥陶系碳酸盐岩储层发育主控因素与分布预测

摘要

The drilling data revealed complex development and distribution characteristics of Ordovician buried-hill carbonate reservoirs in northwestern part of Shaleitian arch, offshore Bohai Sea. According to cores, thin sections, isotope and trace elements, it is defined that the Ordovician carbonate reservoirs mainly consist of dolostone in lithology. Dissolved pores, caves and fractures are representative of reservoir space and main type of reservoirs is fractures-pores. Dolomitization, karstification and tectonism are the main factors of controlling the reservoir development, in which dolomitization is the basic factor, karstification is the important guarantee and tectonism is the key factor. The result of comprehensive seismic and geological prediction shows that the favorable Ordovician karst weathering-crust reservoirs develop in the southwest of the research area.%基于岩心、薄片观察以及同位素、稀土元素等分析资料，明确了渤海海域沙垒田凸起西北部奥陶系碳酸盐岩潜山储层岩性主要为白云岩，储集空间包括溶蚀孔、洞、缝，储层类型为裂缝-孔隙型，裂缝是沟通孔洞的重要通道。储层演化机制上，碳酸盐岩白云石化作用、岩溶作用和构造作用是储层发育的主控因素：白云石化作用是储层发育的基础，岩溶作用是储层发育的重要保障，构造作用是储层发育的关键。地震地质储层综合预测表明研究区西南部为风化壳岩溶储层发育的有利地区。