Velocity model construction and mapping in central area of Junggar Basin

摘要

The structure mapping method with stacking velocity and time-depth conversion is hard to reveal subtle structures in the central part of Junggar basin. Several methods of building velocity field for structure mapping were discussed: velocity analysis based on Dix's formula transformation, model based velocity tomography, model based velocity inversion, and velocity field construction with pre-stack depth migration. Satisfactory results have been achieved in Zhongbu No. 1 block, the central part of Junggar Based on former research, it has been found that structural traps were poorly developed in the area owing to the high stability of the central part of Junggar basin during in the Centrozoic and Mecenzoic time. Hydrocarbon has mainly been traped in subtle structural and litho-stratigraphic reservoirs. Therefore i-dentification and description of subtle structure is highly demanded. Larger amounts of practice testified that structure mapping with spatial varying velocity is the key to i-dentify the subtle structure traps. According to one basin.