A Research on E3 2 Algal-Reef Reservoir in Yuejin Area, Qaidam Basin, Northwestern China
- Received Date: 2001-03-28
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Key words:
- Qaidam Basin /
- Yuejin area /
- algal-reef micrite /
- meteoric water-seawater /
- mixing dolomitization /
- dissolution in meteoric vadose zone
Abstract: E 3 2 lacustrine stratum, located in Yuejin area, Qaidam Basin, northwestern China, is mainly composed of interbedded /intercalated carbonate rock mudstone. Terrigenous debris-bearing micrite,algea-originated laminated micrite,algea-originated stromatolitic micrite,algea-originated micrite and grainstone could be recognized in the carbonate rock, of which algea-originated laminated micrite and algea-originated stromatolitic micrite developed into good reservoir(oil-bearing) with a mean porosity of 25% and mean permeability of proximate 100×10 -3 μm 2. Meteoric water-seawater mixing dolomitization and dissolution in meteoric vadose zone were the main courses for reservoir development. Based on the research of diagenetic sequence, porosity evolution of the algea-originated laminated micrite and algea-originated stromatolitic micrite have been reconstructed. Furthermore, pore and throat diameters and their combinations have been discussed, which play an important role in petroleum development. The determination of spatial distribution for E 3 2 algal-reef micrite reservoir is very important in petroleum exploration in Yuejin area. Log and seismic data also play important roles in prediction of algal-reef micrite reservoir. High SP and SN values imply the exist of petroleum-bearing algal-reef micrite reservoir, while strong seismic reflection shows the lateral distribution of them. Based on the above discussion, spatial distribution of E 3 2 algal-reef micrite reservoir in Yuejin area have been mapped.
Citation: | SUN Yan, SHEN An-jiang, XU Yang, LIN Nian-tian. A Research on E3 2 Algal-Reef Reservoir in Yuejin Area, Qaidam Basin, Northwestern China[J]. Acta Sedimentologica Sinica, 2002, 20(1): 61-69. |