Paleokarstic water tables and their control on reservoirs in Ordovician Yingshan Formation, Tazhong Area, Tarim Basin, NW China
| Autor: | Yunfeng Zhang, Zhenyu Wang, Zhenghong Zhang, Shiyin Li, Xingliang Deng, Haizhou Qu, Maoyao Liu |
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| Rok vydání: | 2018 |
| Předmět: |
geography
geography.geographical_feature_category Landform Water table 020209 energy Well logging Geochemistry Energy Engineering and Power Technology Geology 02 engineering and technology 010502 geochemistry & geophysics Geotechnical Engineering and Engineering Geology Karst 01 natural sciences Unconformity Cave Geochemistry and Petrology lcsh:TP690-692.5 0202 electrical engineering electronic engineering information engineering Ordovician Economic Geology lcsh:Petroleum refining. Petroleum products Sea level 0105 earth and related environmental sciences |
| Zdroj: | Petroleum Exploration and Development, Vol 45, Iss 5, Pp 873-883 (2018) |
| ISSN: | 1876-3804 |
| DOI: | 10.1016/s1876-3804(18)30090-9 |
| Popis: | Based on cores, well logging and karstic paleogeomorphology, the identification method of multi-period paleokarstic water tables and their distribution and control on reservoirs were researched of Yingshan Formation in Tazhong Area, Tarim Basin. Three periods' water tables numbered 1 to 3 have been identified from bottom to top of Yingshan Formation in Tazhong Area. The corresponding typical horizontal undercurrent zones are characterized by single karst fabrics such as sack-like dissolved vugs or subhorizontal channels, combination of various karst fabrics like pre-existing high-angle fractures intersected by small caves and subhorizontal channels, and combination of multi-layered caves and different karst fabrics of large pores. On the plane, periodical rising sea levels caused the development of No.1, No.1 and 2, No.1, 2 and 3 water tables in karst depressions, slopes and highlands respectively. As the result of the nearly horizontal occurrence of Yingshan Formation, submembers of Yingshan Formation had tiny angles with fracture-cave bodies of each period's water table, so the karst reservoirs are characterized by “crossed strata regionally and developed along the stratum locally”. The distance between water table and unconformity, thickness of horizontal undercurrent zone and average thickness of reservoir all tended to increase with the rise of karst landforms. The karst highland and slope had 2-3 periods' water tables and thicker horizontal undercurrent zones, so they had thicker and better quality reservoirs, making them favorable exploration areas. Key words: paleokarstic water table identification, stages and distribution, reservoir-controlled pattern, Ordovician Yingshan Formation, Tazhong area, Tarim Basin |
| Databáze: | OpenAIRE |
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