川中HC地区龙王庙组优质白云岩储层地震预测

Seismic prediction of high-quality dolomite reservoirs in Longwangmiao Formation in HC area of central Sichuan

四川盆地川中地区龙王庙组发育台内高能颗粒滩相白云岩储层,具有一定的勘探潜力,基于HC地区三维地震资料及已钻井等地质资料,开展了相关的储层预测方法研究,主要包括:井震精细标定明确龙王庙组顶、底界地震反射特征;根据已钻井建立模拟储层纵向变化的地质模型,开展正演建立储层地震响应模式;优选对储层敏感的地震属性刻画优质储层的平面展布;多方法联合反演技术,定量刻画储层厚度。综合预测结果表明:HC地区龙王庙组储层纵向上主要分布在中、上部,厚度介于5~70 m;横向上滩体储层呈北东向展布,与磨溪主体展布方向一致,厚层滩体发育区内,存在多个分隔的颗粒滩体。研究结果认为工区A井以东地区是有利的储层发育区。

Intra-platform high-energy granular beach dolomite reservoirs are developed in the Longwangmiao Formation in the central Sichuan Basin,which have certain exploration potential.Based on 3D seismic data and geological data of drilled wells in the HC area,relevant reservoir prediction methods have been carried out.Firstly,the seismic reflection characteristics of the top and bottom boundary of the Longwangmiao Formation were defined by fine calibration between the wells and the seismic data.Secondly,a geologic model was built after an analysis of the existing data and forward modeling was carried out to establish a reservoir seismic response model.Thirdly,according to the selected sensitive seismic attributes,multi-parameters seismic attributes were adopted to describe the plane distribution of high-quality reservoirs.Finally,quantitative prediction of the reservoir was performed through the multi-method joint inversion technique,which can effectively describe the reservoir thickness.The comprehensive prediction results show that Longwangmiao reservoirs in the HC area are mainly distributed in the middle and upper parts of the longitudinal direction,with a thickness ranging from 5 m to 70 m.The lateral upper beach reservoirs are distributed northeastward,which is consistent with the main distribution direction of Moxi.There are multiple separated grain beaches in the thick beach development area.The east part of well A in the work area is a favorable reservoir development area.