LI Zhong1,2, LI Jia-wei1, ZHANG Ping-tong1,2, YU Jing-bo1, LIU Jia-qing1, YANG Liu3
1. Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China;
3. Hangzhou Institute of Geology, PetroChina, Hangzhou 310023, China
Abstract: nified structural-fluid regime identification is a new way to study the diagenesis and reservoir-forming process of deep buried carbonate rocks in superimposed basins. For the Yingshan Formation deep-buried carbonates of the lower-middle Ordovician in Tazhong(up to 6500 m, 220鈩�), Tarim Basin, the research shows that six phases calcite cementation were developed in the carbonates. The former three-phase cements successively formed during the penecontemporaneous, hypergene and shallow burial stages, with diagenetic features related to normal seawater. In contrast, the later two-phase cements of the middle-deep burial process are characterized by evidently negative 未13C values, indicating organic carbon input. Carbonates with maximum negative 未18O and 未13C values in the fourth cement are related to thermal-fluid flow. Beside dissolution occurred in the penecontemporaneous and hypergene stages, two-phase burial dissolutions developed in the Yingshan Formation carbonates of Tazhong, in which the second burial dissolution mainly resulted from alterations of dolomites as well as early calcite cements, coupled with hydrocarbon injection. For the studied area, epidiagenesis and burial dissolution-cementation of the Yingshan Formation carbonates were influenced by the fluid flows that were related to middle-late Ordovician thrust faults in NW strike, Silurian-Devonian transfer or strike-slip faults in NE strike and Permian tension faults.
Key words: structural-fluid regime reservoir diagenesis deep-burial carbonates Ordovician Yingshan Formation Tarim Basin
E-Mail: lizhong@mail.iggcas.ac.cn
Bulletin of Mineralogy, Petrology and Geochemistry Vol.35, No.5, 2016, page 827-838
