准噶尔盆地中部4区块侏罗系头屯河组河道砂体储层识别描述方法

Identification and Description Method of Channel Sand Body Reservoir for Jurassic Toutunhe Formation in the 4^(th) Block of Central Junggar Basin

准噶尔盆地中部4区块头屯河组是该区重要的勘探层系,主要发育冲积平原相、三角洲相和湖泊相等沉积相类型,其中冲积平原相曲流河砂体、三角洲平原亚相分支河道砂体和三角洲前缘亚相水下分支河道砂体是重要的优质储层类型。针对研究区中上述河道砂体埋藏深、多期叠置和地震资料分辨率低等因素造成薄储层描述困难的情况,根据砂体成因,建立了河道砂体叠置关系,分析河道砂体储层地球物理特征;通过地震模型正演并结合地震资料,明确了各类河道砂体储层地震响应特征;在此基础上,利用分频地震属性进行多砂体识别描述,利用地震切片技术进行薄层单砂体识别,均取得了较好的应用效果,为该区块寻找优质储层和隐蔽圈闭描述提供了有效手段。

Toutunhe Formation in the 4th Block of Central Junggar Basin was an important stratum for oil exploration in the area.It developed mainly alluvial plain,delta and lake sedimentary facies.Among them,the alluvial plain meandering river sand body,the delta plain subfacies channel sand body and delta front subfacies underwater branch channel sand body were important high quality reservoirs.Aiming at the buried depth of the above-mentioned channel sand bodies in the sag,the difficulties of thin reservoir description caused by multiphase superimposed and low resolution of seismic data and according to the sand body origin,a superimposed relation of channel sand body was established.The geophysical characteristics of river channel sand body reservoir were analyzed.Through seismic forward model and combined with seismic data,the seismic response characteristics of all kinds of channel sand body reservoirs were cleared.On the basis of the study,frequency division seismic attribute is used to identify and describe the sand bodies.The seismic slice technology is used to identify the thin layer of single sand body,the good application effect is obtained.It provides effective means for looking for high quality reservoirs and subtle trap description in the Central Junggar Basin.