Characterization Of Heterogeneity Of ZJ1-4 Reservoir In WC Oilfield And Its Effect On Bottom Water Rise

With the recovery enhancement of ZJ1-4 reservoir in WC oilfield,the water content increased gradually and the production declined significantly.In order to enhance recovery,it is necessary to deepen the understanding of the reservoir characteristics,and research the reservoir heterogeneity.Septal interlayer distribution is the one of the core contents of the characterization of reservoir heterogeneity,Therefore this paper focuses on the septal interlayer distribution characteristics and the bottom water rising influence,comparing the interlayer distribution of geological reserves and proven reserves,we verify rationality of the interlayer distribution model for the reservoir development adjustment scheme and measures.This paper mainly contains several aspects followed to research and obtain the corresponding results:1)According to the core and borehole petrophysical analysis data and the logging data,the distribution range of porosity and permeability of the reservoir is large,which belongs to medium porosity and medium-to-low permeability reservoir.Porosity and permeability are good correlated.2)Reservoir pore throat structure was analysed according to the only two wells'capillary pressure curve in the study area.Pore throat of Well 15-1-3's rock is distributed uniform,sorting,coarse skewness and good pore structure.The pore throat distribution curve of Well A6hp's rock is bimodal,there are two main pore throat range,poor sorting,thin crooked,bad pore structure of the core In general the reservoir sandstone pore throat is large and sorting,but pore connectivity is poor.Siltstone pore throat is small and poor sorting,but pore connectivity.3)Through the study on the reservoir heterogeneity,the heterogeneity of layer in ZJ1-4 reservoir is medium to serious.the plane heterogeneity is stronger than the layer's,which belongs to the serious heterogeneity.4)Based on the understanding on the reservoir characteristics,combining with the well logging interpretation,the interlayer is divided into muddy intercalation and petrophysical intercalation,and also the criteria for intercalations identification was established:mudstone interlayer,the characteristics of main logging response:GR:90-120API;Vsh:>30%;?:2.2-2.4g/cm3;object interlayer identification standard is:?<21%,<4.5mD,?>2.39g/cm3;Vsh<30%.5)using drilling horizontal section into the oil reservoir and oil location in reservoir and depth,the surface structure of ZJ1-4 reservoir was corrected,and calculated the proven reserves of crude oil of 1 well area in the reservoir(that is XX104m3)by volumetric method.6)Using sequential indicator simulation method,model of interlayerspatial distribution was established,interlayer distribution characteristics of each layer are also analysed.The upper part of ZJ1-4 reservoiris mainly physical layer,physical layer and muddy intercalations are not developed in the middle part and muddy intercalations are not developed,a stable distribution muddy intercalation is developed in the bottom.7)reservoir porosity,permeability,oil saturation and effective thickness of the three-dimensional model were established respectively,based on the reservoir parameter model,through the study on distribution characteristics of the storage coefficient,product of storage coefficient and permeability,it is ensure that the favorable oil and gas accumulation is located in the northwest edge of the study area.8)through the study on the three-dimensional geological model,accounting for reserves is XX104m3,which is smaller(smaller reserves6.15×104m3)than proven reserves,and also highly match the proved reserves,it is further verified the reliability of the interlayer distribution.9)Using Eclipse software to establish the mechanism model.Research shows that the worse interlayer materials are,the more slowly water cut rises,the smaller bottom water effect is,the more ultimate oil production,the less water production with the same oil production.