CHEN Yong, WANG Cheng-jun, SUN Xiang-fei, WANG Miao, HAN Yun, YAN Shi-yong

School of Geosciences in China University of Petroleum (East China), Qingdao 266580, China

Abstract: Pore fluids can cause the change of mineral solubility, which result dissolution or precipitation of mineral in the clastic reservoir, and the formation of dissolution secondary porosity in the sandstone reservoir is closely related to the change of mineral solubility of clastic skeleton grains in geological fluids. This paper summarizes the solubility variations of quartz, feldspar and carbonate minerals according to temperature, pressure, pH value, organic acids, etc. Previous studies that mineral solubility and equilibrium distribution of dissolved components mainly depend on formation temperature and pH value of pore fluids, formation temperature and pH value control the form and content of complex, and the relative content of CO32-, HCO3- and CO2 in formation water dominate minerals solubility. The interactions between fluids and minerals in the reservoir are changed by temperature, pressure, and pH value, therefore the mechanism of dissolution secondary porosity forming is different from condition changing. There are very few previous studies of mineral solubility link to the mechanism of dissolution secondary porosity forming, and we suggest to establish a quantitative relationship between mineral solubility and the characteristics of secondary porosity, it should be paid more attention to do experiment and numerical simulation based on mineral composition of the reservoir rock with different temperature, pressure, fluids and other geological environmental conditions in future study.

Keywords: quartz feldspar carbonate minerals mineral solubility dissolution secondary porosity

E-Mail: yongchenzy@upc.edu.cn  

Bulletin of Mineralogy, Petrology and Geochemistry Vol.34, No.4, 2015, page 830-836