Author's Name: JIANG Wenya, WANG Na, WANG Xiaomin, LIN Changmei, ZHU Bixing, DAI Kun, YU Chao, ZOU Leiluo |
The Kongdian Member-2 of the Paleogene is the main source rock series in Cangdong Sag, Huanghua Depression in Bohai Bay Basin. The oil and gas generated by it are mainly concentrated in the reservoirs of Kongdian Formation and Shahejie Formation. Based on analysis of comprehensive petroleum conditions, three reservoir-forming patterns, i.e. structural-lithologic reservoir in Kong member-1 above source rocks, stratigraphic-lithologic reservoir in Kong member-2 beside source rocks and shale oil in source rocks, have been established with high-quality source rocks as the key factor. The improved genesis method is used to evaluate the conventional oil and shale oil resources with the calculated amounts of the generated, expulsion and residual hydrocarbons based on experiment as constraint. The multi-parameters analogy method is used to calculate the migration and accumulation coefficient and then evaluate the conventional oil resources. The quality-oil-content method is used to evaluate the shale oil resources. The results show that the amounts of conventional oil resources and shale oil resources of Kongdian Formation in Cangdong Sag are about 6.9×108 t and 6.8×108 t respectively, and the remaining oil resources of Kongdian Formation are distributed in three major fields, namely, structural-lithologic reservoirs in Kongdian Member-1, stratigraphic-lithologic reservoirs in middle-low slope areas and shale oil in the central area of the lake basin. The potential of shale oil resources is huge, and it will be the main exploration fileds in the future. |