东海西湖凹陷平北地区断裂发育特征与油气聚集

Fault development characteristics and hydrocarbon accumulation in Pingbei area of Xihu Sag, East China Sea

杨彩虹 曾广东 李上卿 梁若冰

Yang Caihong Zeng Guangdong Li Shangqing Liang Ruobing

中国石化 上海海洋油气分公司, 上海 200120

SINOPEC Shanghai Offshore Petroleum Company, Shanghai 200120, China

西湖凹陷平北地区断层发育，圈闭以复杂断块为主，断裂与油气藏关系密切，断层的发育期次、开启与封闭、组合样式，直接影响到油气的运移、聚集和富集程度。平北地区发育了全盛型、早盛型和中盛型3种类型断层，断层的活动时期、断层两盘的岩性配置以及泥岩涂抹等是影响断层封闭性的主要因素。平湖组早盛型断层封闭性最好，平湖组—花港组全盛型断层封闭性相对较差。不同断层组合圈闭的油气富集程度具有明显差别，顺倾向断层组合圈闭油气富集程度最高，反倾向断层组合圈闭油气富集程度相对较低，顺倾向与反倾向断层组合圈闭油气富集程度居于中等，根据以上认识优选目标钻探效果良好。

In the Pingbei area of the Xihu Sag in the East China Sea, faults are well-developed, and traps are mainly complex blocks. The generation stage, open/close and combination style of faults directly affect the migration, accumulation and enrichment of oil and gas. The faults in the study area can be classified into 3 types: peak-flourishing, early-flourishing and mid-flourishing. The active period of faults, the lithologic configuration at both sides of the faults and shale smear are the key elements influencing fault sealing. The faults of early-flourishing type in the Pinghu Formation boast the best sealing while those of the peak-flourishing type in the Pinghu-Huagang Formations are relatively worse. There are obvious differences in the degree of hydrocarbon accumulation between various combinations of faults. The combinations of cis-dipping faults show the highest degree of hydrocarbon accumulation; the combinations of anti-dipping faults show the lower degree of hydrocarbon accumulation; the combinations of both cis-dipping and anti-dipping faults show the middle level of hydrocarbon accumulation.

中国石化油气勘探重大先导项目“中国石化海域探区勘探潜力与区带评价”资助。

https://doi.org/10.11781/sysydz201401064