油气优势运移方向分析——以渤海东部新近系为例

Analysis of Dominant Migration Pathway: A Case Study on Neogene in Eastern Bohai

曾萱 张宏国

ZENG Xuan ZHANG Hongguo

中海石油(中国) 有限公司天津分公司, 天津 300459

Tianjin Branch of CNOOC, Tianjin 300459

渤海东部新近系成藏与断层的输导密不可分，运移断层控制下的优势运移方向是有利成藏区带及高丰度区块的关键。通过三维地震、钻井及测井等资料识别主要运移断层，划分断裂带内部结构单元及断层面与地层产状的配置类型，基于断层封堵性和断层—地层配置对油气优势运移方向开展研究。结果表明，与主力烃源岩接触面积大、晚期活动性较强的大型断层为主要的运移断层，其断裂带是由中部滑动破碎带和其两侧的诱导裂缝带等不同结构单元组成的复杂地质体；综合岩性配置、产状配置、泥岩涂抹、断裂性质及断面应力等多种因素，对主要断层进行了新近系侧向封堵性的模糊综合判定，结果表明渤东低凸起、庙西北凸起、渤东凹陷东侧缓坡带为油气有利的运聚区带；进一步利用断层面形态与地层产状配置精细刻画寻找油气高丰度区块，与油田勘探实践吻合度较高。上述研究提出了对区域优势成藏区带和具体高丰度区块的预测方法，具有一定的勘探借鉴意义。

The hydrocarbon accumulation of Neogene in eastern Bohai Sea is closely related with fault transportation, and the dominant migration pathway controlled by the migrating fault is a key to the favorable accumulation zone and block with high hydrocarbon abundance. Based on three-dimensional seismic, drilled wells and logging data, the authors conducted the identification of main migrating faults, classified the internal structural units of the faults and the configuration between fault plane and strata, studied the dominant migration pathway based on the sealing capacity and the configuration between fault plane and strata. It indicates that the major faults which contact the source rocks with greater area and strongly activated in late period acted as the main migrating faults, and the fault zone is a geological complex consisting of the broken zones in the central and induced fracture zones on both sides. With the integrated consideration of lithology configuration, occurrence configuration, shale smear, fault property and fault plane stress, a fuzzy evaluation of the lateral sealing of the main faults in Neogene was conducted. It shows that Bodong low uplift, Miaoxibei uplift and the gentle slope on the eastern flank of Bodong sag are the favorable zones for hydrocarbon accumulation. Furthermore, some blocks with high hydrocarbon abundance were predicted by detailed description of fault plane morphology and strata occurrence, and are confirmed by drilling activities. This study on the prediction of preferential reservoir forming zone and exploration block with high abundance provides a reference to the exploration elsewhere.

国家“十二五”科技重大专项“渤海海域大中型油气田地质特征”（2011ZX05023-006-002）。

https://doi.org/10.3969/j.issn.1008-2336.2017.04.021