黄骅坳陷北部马头营凸起馆陶组砂体成因及展布特征

Genesis and Distribution Characteristics of Sandstone Bodies in the Guantao Formation of Matouying Uplift,the Northern Huanghua Depression

综合运用钻井岩心、测井、三维高分辨率地震等资料,对渤海湾盆地黄骅坳陷北部马头营凸起馆陶组砂体成因及展布特征进行了系统的研究。结果表明:馆陶组沉积前期发育2条规模大、延伸较远,呈近NS、NNW—SSE展布的沟槽,指示物源主要来源于北部燕山褶皱带。馆陶组为冲积扇-辫状河-曲流河沉积序列;馆三下段为冲积扇扇中辫状河道和河道间漫流相,发育扇中辫状河道成因砂体;馆三上段为辫状河道和泛滥平原相,发育河床滞留沉积和心滩成因砂体;馆二段和馆一段为曲流河沉积,河床滞留沉积、边滩、决口扇和天然堤是主要的砂体成因类型。馆陶组可划分为3个长期旋回,7个中期旋回,16~19个短期旋回;以短期旋回为单元,建立了馆二段等时地层对比的高分辨层序地层格架;层序格架控制着砂体的分布模式,馆二段短期旋回的下部砂岩发育,是主要的储集层。层控测井约束反演提高了馆二段薄互层河道砂体预测的精度,馆二段各砂层组反演预测平面砂地比反映河道砂体呈NE—SW向的展布特征。

Genesis and distribution characteristics of sandstone bodies in the Guantao Formation of Matouying uplift was made by means of the core data,logging data and three-dimensional seismic data.The results show that two valleys,being large-scale,extending far,and near north-south and NNW SSE direction,had developed in the presedimentation of Guantao Formation（Ng）of Matouying uplift.The deposition is controlled by north provenance.Alluvial fan,braided river and meandering river sedimentary sequence was formed in the Guantao Formation,among which the lower Member 3of Guantao Formation is made up of braided channel and interchannel debris flow facies in the middle fan ofalluvial fan,and braided channel of middle fan is the genesis of sand body;the upper Member 3of Guantao Formation consists of braided channel and flood plain facies of braided river,channel lag deposit and channel bar are the genesis of sand bodies;the Member 2and Member 1of Guantao Formation are meandering river deposit,and channel lag deposit,point-bar,crevasse splay,and natural levee are the main genetic types of reservoir sand-body.Guantao Formation can be identified as three long-term datum plane cycles,seven middle-term datum plane cycles,and sixteen to nineteen short-term datum plane cycles.The high-resolution isochronous stratigraphic framework can be built using short-term sequence cycles as an isochronous stratigraphic correlation unit.The distribution of sand body model is controlled by sequence stratigraphic framework,and the lower part of short-term sequence cycles with the larger thickness of sandstone is the main reservoir in the Member 2 of Guantao Formation.Well loging constrainted high-resolution inversion improves the reservoir prediction accuracy of thin-layer channel sand body based on high-resolution sequence framework,and the plain distribution of net to gross ratio reflects the NE-SW spreading characteristics of meandering channel sand bodies in the Member 2of Guantao Formation.