滇黔桂地区海相地层油气宏观保存条件评价

Evaluation of Macroscopical Preserving Conditions for the Marine Strata of Yunnan-Guizhou-Guangxi Region

滇黔桂地区海相地层经历过多旋回构造运动的叠加,油气保存的分割性强。基于中、新生代构造变形对海相地层整体叠加改造格局的影响,针对滇黔桂地区海相地层的油气保存条件评价提出了整体构造框架区宏观保存体系评价思路,强调构造运动是影响油气保存的根本原因。运用模糊数学的层次分析法和综合评判法,对影响油气保存的断裂作用、盖层有效性、上覆层剥蚀厚度和岩浆活动强度等直接因素进行了宏观保存条件评价。根据综合评判结果,将滇黔桂地区的海相地层划分为3类油气保存区块:十万大山断褶带和楚雄断褶带两个构造区为A类保存区块;南盘江坳陷等6个构造区为B类保存区块;宜山构造带等4个构造区为C类保存区块。

The preservation condition is strong in dismembering because of polycyclic tectonic movement′s superimposition in the marine strata of Yunnan-Guizhou-Guangxi Region.On the basis of tectonic deformation characteristics resulted in Mesozoic-Cenozoic tectonic movements, the evaluation thought based on unitary tectonic framework area, which aims to preserving condition′s evaluation in the marine strata of Yunnan-Guizhou-Guangxi Region, is brought forward.It emphasizes that tectonic deformation is fundamental in affecting hydrocarbon preservation. Faulting activity,caprock validity,uplift and erosion,magma activity directly affect the hydrocarbon preservation,so these factors are used in judging preservation condition by fuzzy mathematics analytical hierarchy process and comprehensive evaluation. According to comprehensive calculation results,three grades regions are subdivided: Shiwandashan Fault-fold Zone and Chuxiong Fault-fold Zone belong to the first grade,Nanpanjiang Depression,the second grade,and Yishan Tectonic Zone,the third grade.