Calculation model of dynamic permeability distribution and its application to water drive reservoir at high water cut stage

Key words:  waler shutoff  time-varying parameter  permeability  dynamic distribution  reservoir simulation5 multi-layer

Abstract:

Calculating formula of relative peimeability curve whose characteristic parameters change with permeability was developed by regression analysis of relative permeability curves of fluvial facies sedimentary unit of uncompartmentalized reservoirs in Shengli Oilfield. The time-varying parameters reservoir simulation model was established considering the change of permeability and relative peAneability curve. Computing program was also programmed. The dynamic permeability distribution rules and recovery degree between layers were analyzed by the program. The results show that considering the change of permeability and relative permeability, the, permeability increases sharply near injection well and expands to production well gradually. The permeability increased degree of high-permeabilily layer is greater than that of low-permeability layer. When the water cut changes from 80% to 98%，further permeability increased range of high-permeability layer is very small, while that of low-permeability layer is big. The difference of recovery degree between layers also becomes larger because of the effect of time-varying parameters.