Potential Evaluation And Classification Of Favorable Areas In The Bohai Bay Basin

The classification of Bohai Bay Basin’s oil and gas exploration potential is based on the comprehensive evaluation of oil and gas’ s superiority on the exploration. Its purpose is to sort the priority of the main oil and gas rich cell, and to improve exploration efficiency.The main influence factors of oil and gas’ s superiority include the quantity of oil and gas resources, oil and gas exploration maturity, oil and gas quality and the external conditions of exploration etc.In Bohai Bay Basin, the oil geological reserves and recoverable resources are mainly distributed in the Cenozoic,which mainly refer to the shallow depth(< 2000m) and the middle depth(2000m-3500m).The gas geological reserves and recoverable resources are mainly distributed in the Cenozoic and Paleozoic, which are mainly refer to the deep depth(3500m-4500m) and middle depth(2000m-3500m), and in the shallow and ultra deepth there also have distribution. There three main environmental in Bohai Bay Basin, they are land, beach and sea area.The main grade of Bohai Bay Basin’s oil and gas is conventional grade.We have done the Oil and gas’ s priority degree comprehensive evaluation on the 36 oil-rich units and 29 gas-rich units, and then analyzed the oil and gas exploration potential. In the comprehensive evaluation we use AHP to establish the comprehensive evaluation index system, selecting ten indexes from the quantity of oil and gas resources, oil and gas exploration maturity, oil and gas quality and external conditions of exploration. The favorable oil exploration area of Bohai Bay Basin includes Bozhong area, Zhanhua depression, Dongying depression, western depression, Liaodong Bay, Qikou depression;and the favorable gas exploration area includes Dongpu depression, Qikou depression, Bozhong area, the Banqiao depression, Dongying depression, Huimin depression, Langgu depression, Western depression.The shale oil and gas resources in Bohai Bay Basin are mainly distributed in the paleogene. After the comparison with the North American shale oil and gas’ s generation and accumulation conditions,we found that there are a lot of similarity between the Paleogene of Bohai Bay Basin and North America. The amount of shale gas resources in Bohai Bay we have predicted through the statistical method, volume method, geologic analogy method is 8.07-11.15 billion m3, and the amount of shale oil resources is 13.146 billion tons. The main shale oil and gas favorable areas located in the Jiyang depression of Dongying area, linnan area, Yangxin area, Chezhen area, Bonan Gubei, Gunan Fulin, Liaohe depression in the western depression area.