渤海K油田浅水三角洲复合砂体成因刻画

Characterizing the Genesis of Composite Sandbodies in the Shallow Water Deltas of K Oilfield in the Bohai Sea

郭诚

GUO Cheng

中海石油(中国)有限公司天津分公司, 天津 塘沽 300459

CNOOC China Limited, Tianjin Branch, Tanggu, Tianjin 300459, China

渤海K油田新近系明下段储层受浅水三角洲沉积控制，复合砂体的内部结构较为复杂。为明确复合砂体成因、沉积期次及单期砂体展布特征，以明下段A砂体为例，从层序划分入手，建立了复合砂体地层结构；在沉积模式指导下，结合测井及岩芯资料厘定了砂体成因；通过井震结合，划分了成因期次，并分期表征了单砂体展布特征。结果表明，A砂体为分流河道、天然堤、末端决口扇、分流间湾，可细分为3个沉积期次，根据各期次内部不同成因类型的砂体接触关系，归纳为分流河道侧切、河间天然堤沉积、河间分流间湾沉积和分流河道-末端决口扇接触等4种类型。

The Neogene Lower Member of the Minghuazhen Formation in K Oilfield of the Bohai Sea is controlled by delta sedimentation in shallow waters, and the internal structures of the resulting composite sandbodies are highly complex. A Sand Body of the Lower Member of the Minghuazhen Formation was used as an example for determining the genesis, periods of sedimentation, and single-period distribution characteristics of composite sandbodies. The stratigraphic structure of composite sandbodies was constructed according to stratigraphic divisions, and the genesis of sandbodies was determined through a combination of well-logging and rock core data under the guidance of depositional models. Through well-seismic ties, the temporal periods of these causes were differentiated, and the distribution characteristics of single sandbodies in each of these periods were characterized. The results indicate that A Sand Body was formed by distributary channels, natural levees, terminal crevasse splays, and interdistributary bays, which may be further subdivided into three periods of sedimentation. The contact relationships of sandbodies in each of these periods may be categorized into four types according to their genetics as lateral splits in distributary channels, interchannel natural levee sedimentation, interchannel-interdistributary bay sedimentation and distributary channel-terminal crevasse splay contact.

10.11885/j.issn.1674-5086.2016.11.25.01