渤海海域渤东凹陷结构特征与勘探方向

Structure Characteristics and Favorable Hydrocarbon Exploration Zone of Bodong Depression in Bohai Sea Area

李春荣

LI Chunrong

中海油研究总院, 北京 100028

CNOOC Research Institute, Beijing 100028, China

通过对渤东凹陷结构特征、凹陷结构演化综合研究,明确了凹陷结构具"东西分带、南北分区"的特征:平面上凹陷东西分带,西部洼陷带呈NNE向半地堑串联分布,东部洼陷带呈NE向半地堑并联分布,剖面上南北分区,由北向南凹陷结构由北区的单一半地堑结构过渡到中区、南区复杂化的半地堑结构;阐明了凹陷结构演化对洼陷生烃潜力的控制;总结了渤东凹陷主要4种油气成藏模式:凸起上覆披覆背斜型油气藏、潜山型油气藏、中央走滑带下生上储型油气藏和斜坡带构造——岩性油气藏;预测了渤东凹陷4个有利勘探区带:渤东低凸起(南段和北段)、中央走滑构造带、西二洼斜坡带和东一洼斜坡带,其中位于主力生烃洼陷西二洼周缘的渤东低凸起南段和西二洼斜坡带是最有利的勘探区带。

Through comprehensive study on the structure and evolution history of Bodong depression, it has been clear that Bodong depression is characterized by zonation between east and west, and division from north to south. In the plane, Bodong depression is divided into east and west zones, being NNE-direction half graben in the west, distributed in series connection. In the east of Bodong depression, the half grabens are distributed as parallel connection in NE-direction. In the section, the structure of Bodong depression changed from simple half graben in the north of depression into complicated half graben in the middle and south of depression. In this paper, it is illustrated that the structure evolution of depression controlled the hydrocarbon generation potential of depression. Four types of hydrocarbon accumulation models of Bodong depression have been established, which are draped anticline reservoirs on the relief, buried hill reservoirs, hydrocarbon generation in the lower source rock and accumulation in upper reservoirs in the center strike-slip fault zone, and structure-lithology reservoirs in slope zone. It is predicated that there are four favorable exploration belts in Bodong depression, including Bodong low uplift, the center strike-slip fault zone, the slope zone of the second low-lying in the west and the slope zone of the first low-lying in the east, of which the southern part of Bodong low uplift and the slope zone of the second low-lying in the west are the most favorable exploration area, which are located near the main hydrocarbon generation center.

国家科技重大专项"近海富烃凹陷资源潜力再评价和新区、新领域勘探方向"(2011ZX05023-001)资助

https://doi.org/10.3969/j.issn.1008-2336.2015.04.001