Evaluation On Pool-forming And Drilling Targets In Th Eastern Of Maichen Sag

Maichen Sag is located in Lei-Qiong depression region in the central south of Beibuwan Basin and the working area in the east is about 400km2. The success of Well X1 indicates that this area has great exploration potential. However, the lower exploration degree, complex surface conditions and subsurface structures, the development of multi-phase faults and strong physical property variation of oil-bearing layer make it difficult to explore further in the area.For the main exploration problems, based on the comprehensive evaluation of hydrocarbon resources, this paper comprehensively and systematically sum up hydrocarbon reservoir-forming patterns, controlling factors and structure framework of this study area, using reservoir prediction and comprehensive seismic interpretation technique. In addition, we conduct the identification of complicated fault block traps, based on the structure interpretation mode, find out several small fault block traps, depict subtly and evaluate the traps. Thus, the favorable exploration belts and drilling targets are provided.Based on the research on the structure comprehensive interpretation and the dissection on the structure distribution characteristics, we drew the following conclusions: Maichen sag was regionally uplift to the north, the main part is near south-north and its section displayed south-faulted and north-overlapped and there are three structural belts whose trend are NNW; Liusha guang formation is the most favorable reservoir-cap rocks assemble, the overall thickness of the mudstone is becoming thinner and thinner towards NW. The reservoirs developed mainly in the north, the porosity is between 11%-16% and the physical properties is becoming better and better from SE to NW. The central ramp region is the beneficial exploration belt of this pool-forming assemble. Utilizing the comprehensive research ,we thought, the mode of migration is dominated by self-generation , self-reservoiring and near oil sources. By means of using reservoir prediction ,preservation condition , prospection of reservoir and hydrocarbon source rock distribution and other study, we believed that the inner ramp region of three dimension near the deep sag is the most favorable belt. So we have determined three drilling targets and well locations.