Abstract:

Gangdong fault is a critical reservoir-controlling fault in the north of Qikou sag. In order to study the oil and gas distribution of Sha-1 Lower Submember in the Gangdong fault of Qikou sag, there are two cases of oil and gas transporting forms recognized: The distribution position of the entire oil and gas transporting form from the Gangdong fault to the Sha-1 Lower Submember sand body was predicted based on the overlapping of the following three key factors, the transport site of the Gangdong fault in Sha-1 Lower Submember, the regional mudstone cap sealing site of Sha-1 Middle Submember, and the connected sandbody distribution site of Sha-1 Lower Submember. The distribution position of the partial oil and gas transporting form from the Gangdong fault to the Sha-1 Lower Submember sand body was predicted based on the overlapping of the following four key factors, the transport location of Gangdong fault within Sha-1 Lower Submember, the unsealed location of regional mudstone cap of Sha-1 Middle Submember, the distribution location of connected sandbodies of Sha-1 Lower Submember, and the overlying regional mudstone cover of Minghuazhen Formation. The results show that: The entire oil and gas transporting form is mainly distributed in the east and west, while partial oil and gas transporting form is mainly distributed in the middle and locally in the east. The distribution position of the entire and partial oil and gas transporting form controls the distribution of the entire oil and gas fault in Sha-1 Lower Submember of Gangdong fault.

Key words: Qikou sag, Gangdong fault, Sha-1 Lower Submember, sand body, oil and gas transporting form, distribution position