Discovery of early tertiary hydrothermal activity and its significance in oil/gas geology, Dongpu Depression, Henan Province, China

Tertiary hydrothermal activity and its effect on reservoir properties in the Xihu Depression, East China Sea

“…For example, cyclic thermal convection in sedimentary basins on the western coast of Canada generated a dissolution zone of carbonate minerals and improved reservoir quality (Charlou et al 2010;Schmidt et al 2011). In the Pearl River Mouth Basin in China, magmatism not only caused relatively strong deformation and contact metamorphism but also provided a significant amount of heat, which resulted in abnormally high geothermal gradients accelerating the maturation of hydrocarbon source rocks and leading to the release of more organic acids, resulting in the development of secondary porosity (Nie et al 2005;Zhu et al 1994). Sugisaki and Mimura (1994) proposed that hydrothermal fluids rich in CO 2 underwent a chemical reaction with the reservoir rocks, causing the dissolution of quartz and feldspar particles which improves the reservoir properties of these rocks.…”

“…Sugisaki and Mimura (1994) proposed that hydrothermal fluids rich in CO 2 underwent a chemical reaction with the reservoir rocks, causing the dissolution of quartz and feldspar particles which improves the reservoir properties of these rocks. Evidence for intrusive magmatic activity has been identified in different regions across the world during exploration for oil and gas, such as in the Michigan Basin in the United States (Wierzbicki et al 2006), the Songliao Basin and the Jiyang Depression in eastern China (Wang et al 1990), the offshore Bohai Bay Basin in Eastern China (Wang and Zhang 2001), the Dongpu Depression in eastern China (Zhu et al 1994) and the offshore Yinggehai Basin in Southern China (Wang et al 2010). In these basins, magmatic hydrothermal fluids have altered the reservoirs, and most of these altered reservoirs form a group of key hydrocarbon play pathways.…”