Analysis of physical properties of middle-deep reservoirs in the east of Jizhong Depression

Abstract

The Jizhong Depression is one of the hot spots for oil and gas exploration in North China. As the Jizhong Depression has the largest area and richest oil and gas resources, the Raoyang Depression has good prospects for exploration. This paper takes the middle-deep reservoirs of the Shahejie Formation in the Raoyang Depression as the research object. Aiming at the problem of the unclear characteristics of the middle-deep reservoirs in the Raoyang Depression, using core description, thin section identification, and cathodoluminescence technology, the physical properties of the middle-deep reservoirs in Shahejie are clarified. The following points of understanding have been obtained: The rock types of Shahejie Formation in Raoyang area are mainly feldspar sandstone and detrital feldspar, followed by feldspar detrital sandstone and feldspar quartz sandstone. The main mineral content of different structural belts is different. The quartz content in Suning and Maxi areas is higher than that in Liuchu and Dawangzhuang areas. The feldspar content in Liuchu and Dawangzhuang areas is higher than that in Suning, Maxi and Liuxi areas. The Maxi area has the highest lithic content. There are 7 types of pores, including intergranular pores, intragranular pores, granular dissolved pores, mold pores, intergranular dissolved pores, intragranular dissolved pores, and intergranular pores. The porosity in Raoyang area is between 0.85% and 35.26 % with the average value of 12.05%. The permeability is 0.01mD-1312mD, and the average value is 12.75mD. It belongs to low porosity-low permeability reservoirs. Finally, combined with sedimentary facies characteristics and actual drilling and logging data, the reservoir division of the study area is completed, and 10 favorable areas are proposed. The research results provide a reference for the next step in the study of the physical characteristics of the middle and deep reservoirs in the eastern part of the Jizhong Depression.