Analysis of Hydrocarbon Accumulation Characteristics in Small Scale Depression in the New Exploration Area in Southern Songliao Basin-An Example of Zhangwu Fault Depression

There are more than twenty small fault depressions in newly registered blocks of SINOPEC in southern part of Songliao Basin, with an effective area of 100~300 km², and present residual thickness less than 3000 meters. In these depressions, the tectonic evolution history, hydrocarbon generation and petroleum accumulation process are similar. According to the study results on the characteristics of hydrocarbon accumulation in Zhangwu fault depression, it is indicated that the oils were generated from low mature source rocks, and near the source material. The sand body distribution is controlled by steep slope, the reservoir distribution is controlled by sedimentary facies, and hydrocarbon accumulation is controlled by structures. Then, hydrocarbon accumulation models are established for slope belts, depressions and step faulted belt.