ROCK TYPES AND RESERVIOR SPACE ANALYSIS OF THE SHALES OF THE LOWER SECTION OF Es3 TO THE UPPER SECTION OF Es4 IN ZHANHUA SAG

There is favorable potential for shale oil and gas exploration of the lower section of Es3 to the upper section of Es4 in Zhanhua Sag. So the study of this section can help to guide the exploration and development of shale oil... [ view full abstract ]

There is favorable potential for shale oil and gas exploration of the lower section of Es3 to the upper section of Es4 in Zhanhua Sag. So the study of this section can help to guide the exploration and development of shale oil and gas in Zhanhua Sag. Using techniques such as core observation, thin section, the analysis of whole rock and clay X diffraction and SEM, to analysis that the main mineral components in Zhanhua Sag are carbonate minerals, detrital minerals and clay minerals, characterizing with the high content of carbonate minerals. The shales in the study area are classified as limestone, argillous limestone, argillaceous limestone, lime mudstone and calciferous mudstone. Meanwhile, discussing the shales reservoir space types in the area are pore types and fracture types. The pore types include intercrystal pore in clay minerals, intercrystal pore in carbonate minerals, intercrystal pore in pyrite, intergranular pore in detrital minerals, organic material pore and intragranular pore. The fracture types include tectoclase and non-tectonic fracture. Non-tectonic fracture can be classified as diagenetic fracture and abnormal pressure fracture. According to the analysis, the main factors controlling reservoir space are depositional environments and tectonic settings, lithology and mineral composition and abundance of organic material.