Heterogeneity Evaluation And Geological Modeling Of High Water-cut Fault Block Reservoirs

Due to the complex situation of heterogeneity and seepage conditions after longterm water flooding,the further development of “double-high” reservoirs requires efficient optimize plans based on solid analysis of development data to reduce water cut.In this study,analysis of both statistic and dynamic data was taken to re-congnize and evaluate the seepage feature and heterogeneity characteristic of the reservoir during the late stage of the development,based on which the refined reservoir geology model and numerical simulation model were built.In this research,we used several methods to describe the heterogeneity of the field,e.g.secondary welltesting analysis which re-interpreted the percolation feature of near wellbore region,and the inverse calculated interwell permeability;the results illuminated that the statistic permeability from the laboratory is much larger than the dynamic permeability from well-testing analysis,and the interwell permeability would increase along with the water cut rising.We also used the welltest analysis to evaluate the plain heterogeneity of each well,and used inversed water channeling mathematical model to evaluate the interwell heterogeneity;the results showed the characteristic of the composite reservoir of near wellbore region due to high pressure water injection,and the division of interwell flow field due to the long term water injection.Based on proper decisions of modelling methods,the refined geology model was built;the structure of faults and the distribution of facies were meticulously depicted,while the proper interpolation algorithm to present the distribution of properties was selected according to the well pattern;the numerical simulation method was used to verify the geology model and to predict the distribution of residual oil;the results of history match by adjusting parameters referring to heterogeneity analysis showed that the geology model presents the reality well,and is capable of making reliable project scenarios.A procedure of “double-high” complex fault-block reservoir was established during this research,which can be used as supporting technologies to enhance oil recovery in oil fields of the similar situation.