断陷湖盆水道型湖底扇沉积储层预测——以莱州湾凹陷沙三中亚段为例  

Reservoir prediction of channel sublacustrine fan in faulted lacustrine basin:take the middle sub-member of the Third Member of Shahejie Formation in Laizhouwan Sag as an example

作　　者：王志萍 官大勇 郑敬贵 付鑫 王启明 WANG Zhiping;GUAN Dayong;ZHENG Jinggui;FU Xin;WANG Qiming(Tianjin Branch of CNOOC(China)Ltd.,Tianjin 300452,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300452

出　　处：《海洋地质前沿》2023年第12期79-87,共9页Marine Geology Frontiers

基　　金：国家科技重大专项“渤海海域勘探新领域及关键技术研究”(2016ZX05024-003)。

摘　　要：渤海湾盆地莱州湾凹陷沙三段发育大型水道型湖底扇岩性圈闭,成藏背景较好,勘探潜力较大,但湖底扇沉积特征不明确,储层分布难以精细刻画,制约了勘探的进程。因此,在地震沉积学、沉积学理论指导下,提出了以不同重力流水道类型地震相分析为基础优选敏感属性,平面剖面结合精细刻画湖底扇的展布,最终确立有利储层发育区的技术思路,以期为研究区湖底扇型岩性油气藏勘探部署提供有利的支持。分析认为,湖底扇水道具有中−弱振幅、杂乱反射特征,与湖相泥岩的平行连续、强振幅反射具有明显差异,以此为基础优选分频倾角相干和基于灰度共生矩阵的地震结构属性及神经网络波形分类技术对湖底扇边界以及内幕水道进行刻画。其中,限制水道复合体及叠置水道复合体砂岩厚度大,两类水道发育区域是研究区的有利储层发育区。限制水道复合体分布在F1断裂坡折带下,水道厚度及宽度较大;叠置水道复合体分布在F2断裂坡折带下。Large channel sublacustrine fan lithologic traps are in the Third Member of Shahejie Formation in Laizhouwan Sag,Bohai Bay Basin,with good reservoir forming background and great exploration potential.However,the sedimentary characteristics of sublacustrine fan are not clear,and the reservoir distribution is difficult to be delineated,which restrict the exploration process.Therefore,under the guidance of seismic sedimentology and sedimentology theory,a method of optimizing attributes based on seismic facies analysis of different gravity flow channel types was proposed,and the distribution of sublustrine fan was described in detail with plane section,and favorable reservoir development area was finally established.This study will provide favorable support for the exploration and deployment of sublacustrine fan lithologic reservoirs in the study area.It is recognized that the sublacustrine fan channel has the chaotic characteristics of medium and weak amplitude,which is obviously different from the parallel and continuous strong amplitude reflection of lacustrine mudstone.Based on this,the coherence attribute of frequency-divided dip coherency,seismic structure attribute based on gray level cooccurrence matrix and waveform classification technique of neural network were selected to characterize the boundary of sublustrine fan and the inner channel.The sandstone thickness of restricted channel complex and superimposed channel complex is large,and the two channel development areas are favorable reservoir areas in the study area.The restricted channel complex is distributed under the slope break zone of F1 fault,and the channel thickness and width are large.Superimposed channel complexes are distributed under the slope break zone of F2 fault.

关 键 词：水道型湖底扇 沉积储层预测 断陷湖盆 沙三中亚段 莱州湾凹陷 

分 类 号：P744.4[天文地球—海洋科学] P618.3