根据地震和钻井资料研究沉积相

STUDY OF SEDIMENTARY FACIES BY USING THE SEISMIC AND WELL DATA

南海西部石油公司

本文根据地震和钻井资料, 结合电测曲线及区域地质情况, 对ZH坳陷西部早第三纪沉积相进行了综合分析。考虑到沉积相的演变规律, 采用单井划相与地震地层学相结合的方法, 将ZH坳陷西部早第三纪沉积相划分为七种主要类型:冲积扇相、河流平原相、滨浅湖相、半深～深湖相、河湖过渡相、滨浅海相及海陆过渡相。通过沉积相演化的研究, 可以推断早第三纪早期由于湖面水体不断加深扩大, 在坳陷内形成良好的生油条件;晚期海水侵入形成海陆过渡相沉积, 有利于各种砂岩体的形成, 为ZH坳陷内主要储集层段。

Based on the seismic and well data, taking account of the materials of well logging and regional geological conditions, an integrated study for the sedimentary facies of Palaeogene system in the western part of the ZH depression was carried out. By considering the development of the sedimentary facies and combining the single-well fades-determination with seismic-stratigraphic study, the sedimentary facies of the Palaeogene system in this area were categorized into seven types, e.g., the facies of alluvial fan, of river plain, of shallow lake deposit, of medium depth lacustrine, of river-lake transition, of lattoral deposit, and marine-continert transition.It could be deduced from the research of sedimentary facies that owing to the lake water became more and more deeper and wider as time went on during the early stage of Palaeogene, there has a favorable environment for oil accumulation. During the late period of Palaeogene, because of the transgression, the sedimentary facies became a marine-continent transition one. This is profitable for the forming of the sand body and such a sand bpdy is proved to be the main oil-bearing reservoir in this depression.