辽中凹陷北部湖底扇沉积模式及地震响应特征

综合利用辽中凹陷钻井和地球物理资料进行井—震标定、地震地层学解释和地震相分析.在东营组二段(简称东二段)沉积时期,该区分布多个NE向古辽河水系发育的三角洲沉积体系,存在前缘相带砂体整体滑塌并近距离搬运而形成的湖底扇沉积.湖底扇具有期次多、数量大和横向展布范围广等特点,不同沉积亚相(内扇、中扇、外扇)具有敏感的地震响应特征.分析锦州20构造测井资料的岩—电组合特征,探讨湖底扇形成条件,建立湖底扇的沉积模式,识别湖底扇沉积各亚相的地震响应特征;基于井—震标定技术,利用地震相干体和地震属性方法,研究2期湖底扇沉积横向展布特征,精细刻画有良好油气发现的Ⅱ期湖底扇中扇亚相储层发育边界.结果表明:应用湖底扇沉积模式和地震响应特征,在辽中凹陷北部东二段发现多个湖底扇沉积体,是有利的岩性油气勘探目标,对渤海海域岩性油气藏勘探具有指导意义.

Sedimentary model and seismic response characteristics of the sublacustrine fan in Northern Liaozhong Depression

Sublacustrine fan is the main sedimentary type in paleogene in northern Liaozhong depression.It has good reservoir potentiality and oil-gas possibility,and a large scale of petroleum has been discovered.By the comprehensive application of calibrating downhole seismic,seismic stratigraphic interpretation & seismic facies analysis,it suggests that many delta deposits are developed in the central depression of eastern Liaoning gulf,which is controlled by ancient Liaohe River with northeast direction.Meanwhile,the sublacustrine forms because of the short distance transportation of the slump of the delta front into the lake floor.These sublacustrine fans develop with multi-periods,large account and widely distribution.What is more,it has sensitive seismic response characteristic in different subfacies.Taking the structure of Jingzhou 20 for an example,by analyzed the character of the lithologic compages and logging curves,this study discussed the formation condition of the fan and established sedimentary model and identified seismic response characteristics;based on the fine calibration of the downhole seismic,seismic coherence cube and seismic attribute method were used to study the plane distribution of the sublacustrine fan,and especially the petroliferous middle fan was subtly depicted.The study result showed that more Sublacustrine fans discovered in Dongying group of neogen at the northern LiaoZhong depression by established sedimentary model and geophysical response of sublacustrine fans,and are great the exploration target.The Research results are important for lithology oil and gas exploration in the Bohai sea.