由于曲流河横向摆动大,使河道沉积在空间上错列叠置,沉积体系内没有等时面和稳定的标准层,给砂体追踪造成很大困难.采用地震测井联合反演技术,提高了点坝砂体的分辨率.在建立岩相、测井相和地震相基础上,充分利用岩心的直观性、测井纵向分辨率高和地震横向连续性好的特点,提高了纵向上不同期次河道单元的划分和横向对比的准确性.把砂体厚度等值线、测井相和地震波阻抗沿层切片叠置,准确识别出了废弃河道、点坝、泛滥平原和决口扇.根据国内外现代曲流河和露头资料的统计分析,建立了点坝几何参数之间的相互关系,提出了点坝侧积体、侧积面和侧积层的确定方法与内部构型的研究方法,为建立准确的地质模型提供了可靠的约束条件.%Because the lateral oscillation amplitude of a meandering river is large,channel deposits are in stagger arrangement and there are no isochronous surface and stable marker bed in the sedimentary system,which leads to difficulties for sand body tracing.The use of well logging-seismic joint inversion technology can improve the resolution of sand body in point bars.Based on the establishment of lithofacies,logging facies and seismic facies and making full use of the characteristics of cores,high vertical resolution of logging curves and good lateral continuity of seismic signals,the accuracies of vertical classification and lateral correlation for channel units of different periods are improved.Abandoned river channel,point bar,flood plain and crevasse splay are identified accurately by overlapping sand body thickness contours,logging facies and seismic wave impedance slices.Based on the statistics of modern meandering river and outcrop data at home and abroad,the paper establishes relationships among geometrical parameters of point bars,puts forward methods to identify lateral accretion body,accretion surface and accretion bed of point bars and a method for internal architecture study,which provides reliable constraint conditions for accurate geological model establishment.
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