巨厚油层隔夹层特征及其对剩余油分布的影响——以渤海湾盆地L油田为例

Characteristics of interbeds in thick oil layer and its effect on remaining oil distribution: a case study of L Oilfield, Bohai Bay Basin

李红英 陈善斌 杨志成 王欣然 刘斌

中海石油（中国）有限公司天津分公司，天津 300452

Tianjin Branch of CNOOC Ltd., Tianjin 300452, China

渤海湾盆地L油田巨厚砂岩油藏隔夹层分布复杂，严重影响油田水驱开发效果和剩余油预测。为此，依据岩心、测井以及油藏动态信息等资料，以东二下亚段Ⅱ油组为研究对象，精细解剖该层段内隔夹层成因、类型及分布特征，阐明其对剩余油分布的影响。结果表明：目的层发育泥质、砂砾岩质2类不同岩性的隔夹层。纵向上，层间夹层的稳定程度高于层内夹层，层内夹层的稳定程度自下而上依次变差；平面上，水下分流河道向水下分流河道间（或湖泊区域）层间夹层明显变厚，层内夹层逐步发育。层间夹层影响流体垂向渗流作用，致使目的层隔夹层上方储层顶部剩余油富集。该研究成果为后期油田挖潜提供了有力的地质依据。

The complex distribution of the thick sandstone reservoir interlayers in the Bohai Bay Basin seriously restricts the water flooding and remaining oil prediction in the L Oilfield. Based on the cores, well-logs and dynamic reservoir information, this paper presents the origin of the interbeds in the Ⅱ oil set of the E3d2L Formation, types and distribution characteristic of the interlayers. The results show that two types of interbeds which are muddy interlayers and sandy interbeds are developed in the Ⅱ oil set of E3d2L Formation. The stability of the interbeds is better than the intraformational bed, and the intraformational bed shows a descending stability from the bottom to the top; in the plane, an increasing thickness of the interbeds developed from distributary channel deposits to the inter-distributary bay deposits, as well as the intrafomational bed. The vertical seepage factor is affected by the interlaminar, and the residual oil is concentrated because of the interlayer blocked the water injection from the bottom of the Ⅱ oil set of E3d2L Formation. The research results provide a strong theory support for the later stage exploration in the L Oilfield.

10.6056/dkyqt201806005