The Phased Geological Modeling And Heterogeneity Evaluation In Wen 31 Fault Block

The oil-field Wen 31 has entered the mid- to late periods of the development, some blocks exposed the phenomenon such as the strong reservoir heterogeneity, the contradiction in injection-production, large difference of production well section, the relationship is not unified in oil-water, and oil-reservoir water flooding level is very serious, that brings larger difficulties to the rolling exploration and improve oil recovery. Therefore, it needs to carry out the work of reservoir fine description and set up phased model. On the basis of this study, the reservoir of the deposit sediment is studied.The deterministic modeling method is the main way in this phase control trend modeling, which based on the sedimentary microfiches study. It uses the sedimentary facies and the control function of fluid relative to reservoir parameters to achieve the forecast in interwell reservoir parameters.But the above reservoir established by the phase control trend model is only the distribution of geological trend, which are from the sedimentary microfacies characteristics and the liquid phase distribution. It is in order to truly reflect the actual reservoir distribution and changes and needs to use the combination of phase control trend model and Kriging technique. The sedimentary microfacies and fluid phase control the variation trends of reservoir on the macro, and in the same phase belt, it uses the Kriging technique to forecast and distribute the interwell reservoir changes. This method is not only considering the information of sedimentary microfacies and fluid phase controls of the reservoir, and also considering the actual drilling controls the local changes.Therefore, this study focuses on the reservoir parameter change trend got by the phased modeling, and combines with the existing development dynamic data(such as water injection, profile control, etc.), and evaluates the heterogeneity of the reservoir, and the following conclusions are drawn:1) There are 4 main small layers in Wen 31 fault block. The heterogeneity is strong where in addition to the near faults or away from the provenance of interlayer. The interlayer heterogeneity of sandstone internal is weak and the number of interlayers is less.2) The main developments of Wen 31 fault block are underwater diversion channel and estuary sand dam. Their sedimentary rhythm is better. The underwater diversion channel is the positive rhythm and the estuary sand dam is the reverse rhythm deposition. The intraformational inhomogeneity of ?3 small layer is the strongest in 4 main small layers, and The intraformational inhomogeneity of?6 small layer is the weakest.3) On the plane, heterogeneity of the reservoir physical parameters are weak along the direction of the river, and the heterogeneity is strong along the fault direction. The heterogeneity of ?3 and?5 small layers is strong along the fault direction. communication is poor, and come into being some isolated reservoirs of low permeability; The underwater diversion channel developed well in ?4 and ?6 small layers, and The fault strike heterogeneity is weak, and the connectivity is good. In particular, ?6 small layer, the degree of anisotropy is the weakest, is an ideal reservoir.4) Through the analysis of dynamic data, plane heterogeneity of oilfield injection production effect of maximum plane, it is mainly controlled by sedimentary microfacies. The time is shortest when injecting water for development along the underwater diversion channel and the result of ineffective is best. And the effect of liquid extraction and profile control was also significant. The heterogeneity of ?3 small layer is strong, and it has a large oil-bearing area. But its development effect is poor, so ?3 small layer is the key position of tapping the remaining oil after.