Abstract:

On the basis of the current research on the hydrocarbon accumulation theory and hydrocarbon dist ribution rules , the theory of hydrocarbon heterogeneous distribution was definitely put forward. Taking the lithologic hydrocarbon reservoirs in the middle section of the third member of Shahejie Formation (Es₃² ) in Niuzhuang Depression as the main example , the effect factors and the forming mechanisms for the hydrocarbon heterogeneous distribution have been discussed in detail. The heterogeneous distribution of hydrocarbon has several levels , of which the main affecting factors are different. In subdepressions , oil source and trap conditions were the main factors controlling heterogeneous distribution of petroleum macroscopically. In the secondary block , the heterogeneous distribution is controlled by oil source , structural conditions , in addition to the reservoir heterogeneity. The heterogeneous distribution of single sand body or the interior reservoir was resulted from reservoir heterogeneity. The idea that reservoir heterogeneity affects the hydrocarbon accumulation and leads to heterogeneous hydrocarbon distribution was stressed here. The phenomenon that hydrocarbons distribute heterogeneously in different scale is universal and objective , and it is even obvious in the subtle and complex reservoirs , including lithologic reservoirs and buriedhill reservoirs and so on. The presentation about the theory of hydrocarbon heterogeneous distribution takes a significant part in the exploration of lithologic reservoirs and complex reservoirs , and the fine exploration and development in highdegree exploratory areas , and it will play a great role in the reservoir evaluation , hydrocarbon reserves calculation , well deployment and so on.

Key words: fracture , anisotropy , seismic attributes , attenuation , reservoir prediction , Jizhong Depression