| Exploration has made great progress in Lower Paleozoic carbonate rock in eastern Tarim Basin in recent years but confused reservoir types, controlling factors and spatial distribution regularity still are the technical problems so as to affect domain evaluation and well site deployment. Based on outcrops, cores and thin sections from 20 wells, and well logging and geochemical data, five types of reservoir are recognized in the eastern part of Tarim Basin, which include: (1) Ordovician Yijianfang-Upper Yingshan reef-shoal dissolved limestone reservoirs, (2) Ordovician Lower Yingshan-Penglaiba dissolved dolomitized reservoirs, (3) Cambrian platform margin bioherm-shoal dolostone reservoirs, (4) Upper Cambrian slope deep-water gravity-flow dolostone reservoir, and (5) Upper Sinian microbial bioherm-shoal dolostone reservoirs. The dissolved dolostone reservoirs and platform bioherm-shoal dolostone reservoirs are the most significant types of reservoirs in this area. Reef or bioherm-shoal and dissolution are the main controlling factors for reservoir development.Two present exploration domains and three risk exploration domains are evaluated, which provides technical support to petroleum exploration in this area. |
