Fine Study on the Inter-layer in Heterogenetic J2Ⅱ Oil Series in Weizhou XX Oilfield by Logging Data

J2Ⅱ (ZhujiangⅡ)oil series is the objective pay zone in Weizhou XX oilfield. The core and logging data show that there are some inter-layers developed in the J2Ⅱ oil series.It is unable to further study the effect of the inter-layer on the rising velocity of water-cutting due to the limitation of relevant data and the uncertainty of the distribution range of inter-layer. Based on the core and well logging data,the authors conducted a fine study on the inter-layer through dividing the inter-layer into argillaceous inter-layer and calcareous inter-layer, determining the identification method and calculation model of inter-layer, and establishing the criteria of inter-layer classification by permeability.It can be divided into three levels by three grades of permeability,namely medium-high permeability, low permeability and extra-low permeability. The fine depiction of inter-layers in J2Ⅱ oil series provided key information for re-establishing the fine geological model, and also laid a foundation for the subsequent reservoir numerical simulation study of water-cutting rising.