柯克亚气田西八段砂体及有利区地震预测

Seismic prediction of sand bodies and plays in the 8^(th) member of the western Xihefu Formation in the Kekeya Gas Field,Southwest Tarim Basin

塔里木盆地西南部柯克亚气田的主力含油气层新近系西河甫组八段为一套辫状河砂泥岩沉积,储层非均质性较强,属于岩性控制的凝析气藏,预测砂体的空间展布已成为该气藏开发调整的瓶颈。为此,在理清研究思路的基础上,开展了如下工作:应用高分辨率层序地层学对比技术进行了西河甫组小层划分;以三维地震资料为基础,进行精细层位标定确定砂体(储层)的地震响应特征;遵循等时原则1×1加密解释到砂层组;利用储层反演和三维可视化技术追踪河道砂体的分布范围;借助开发井丰富的动、静态资料,采用综合研究方法对砂体进行匹配分析,预测出了有利砂体的分布范围。实际应用结果表明,该研究成果在西八段凝析气藏的开发调整中取得了明显效果,为该区河道砂体追踪预测提供了研究方法和技术手段。

The major hydrocarbon pay zones in the Kekeya Gas Field are a set of sandstones and mudstones of braided river facies in the 8th member of the Neogene western Xihefu Formation,Southwest Tarim Basin,where the lithology-controlled condensate gas reservoirs have relatively strong heterogeneity.To accurately predict the spatial distribution of sandbodies is a bottlenecking problem in adjusting the development plan of this gas field.In view of this,the high resolution sequence stratigraphic correlation approach was first used to perform subdivision of the western Xihefu Formation.Then,the seismic response signatures of sandbodies(reservoirs) were determined through fine horizon calibration based on 3D seismic data.Seismic interpretation was refined(1×1) to single sand unit according to the principle of isochronism.Reservoir inversion and 3D visualization techniques were used to trace the distribution of channel sands.Based on the abundant dynamic and static production data of exploratory wells,an integrated method was applied to predict the distribution of favorable sandbodies.These methods were successfully used to trace and predict the distribution of channel sandbodies,providing a solid basis for adjusting the development plan of the condensate gas reservoirs in the 8th member of the western Xihefu Formation.