高分辨率层序地层学及砂体展布规律研究实例

苏5区块自2005年合作开发以来，目的层段的层位划分一直存有争议。运用高分辨率层序地层学理论与技术，对苏5区块盒7、盒8段进行了精细划分和对比，共识别出2个长期、5个中期和11个短期旋回层序，建立了区内高精度的地层对比格架。从划分结果来看，中、短期旋回层序结构类型自下而上由A型向C型转化，并以相应层序基准面旋回上升期砂体发育程度为最好。采用地质统计学方法描述了层序格架内砂体的纵横向展布规律，并以中期基准面旋回的上升和下降半旋回相域为等时地层编图单元编制了各中期旋回的沉积微相和砂体分布图，预测了有利砂体的分布，为气田下步滚动勘探开发提供了地质依据。

CASES STUDY ON HIGH RESOLUTION SEQUENCE STRATIGRAPHY AND SANDBODY DISTRIBUTION RULE

How to divide target horizon is all the time a dispute since cooperating to develop the Block Su 5 in 2005. This paper not only recognizes 2 long term, 5 mid term and 11 short term cycle sequences after fine classification and analysis of members HE 7, 8 in the Block Su 5 through adopting high resolution sequence stratigraphy theory but also establishes stratigraphic correlation framework with high accuracy in this block. It can be shown from the dividing result that the structural type of middle term and short term cycle sequences transforms from bottom type A to top type C and sandbody during relating rising period of base level cycle develops best. The planar and horizontal distribution rules of sandbody in the sequence framework are described by using geostatistics. Sedimentary microfacies and sandbody distribution maps are drawn by taking half rising and falling cycle of middle term base level cycle as isochronous stratum, and the distribution of beneficial sandbody is forecasted, which provides geological references for further exploration.