油藏开发阶段陆相地层高分辨率层序精细对比探讨

高分辨率层序对比主要依靠各井岩性旋回来识别基准面旋回.对于复杂多变的陆相地层,在油藏范围内进行短期层序对比时不可避免地受到各类自旋回沉积、地层侵蚀和缺失、沉积微相空间变化等因素的影响,从而增大了对比难度.由于这些因素的存在,对比时要区分地层记录中的异旋回和自旋回沉积;充分利用各种关键界面及标志层信息进行约束;开展沉积微相研究,总结沉积微相与基准面旋回变化的关系;对密井网的砂泥岩薄互层区采用井信息进行粗化去除部分干扰信息;并借鉴其他资料,提高层序对比精度.

High-resolution sequence correlation of continental strata in the phase of reservoir development

High-resolution sequence correlation mainly utilizes lithologic cycles to identify base-level cycles.In complex continental formation,short-term sequence correlation within a reservoir may be disturbed by various autocyclic depositions,stratigraphic erosion and gap,space variation of micro-facies and so on,and these factors make the sequence correlation more difficult.So it is important to distinguish between autocyclicities and allocyclicities with different genesis mechanisms in stratigraphic records,and various key interfaces and marker beds should be made full use of.The relationship between sedimentary microfacies and the variation of base-level cycles should be understood by means of the study of micro-facies.The noise in the information from the wells in the thin sand-mudstone interbed area with dense well network should be removed by coarsening well information.Moreover,other core and logging data,such as microelement,clay volume,FMI can also be used in stratigraphic correlation in order to improve the precision of stratigraphic correlation.