水驱油藏高含水期渗透率的动态分布计算模型及应用

通过对胜利油区整装油田河流相沉积单元相对渗透率曲线的回归分析,建立相对渗透率曲线特征参数随渗透率变化的计算公式;考虑渗透率、相对渗透率曲线的变化,建立考虑储层参数时变特征的油藏模拟系统,并编制相应的计算程序;利用计算程序分析多层油藏合采的层间渗透率动态分布规律及其对层间采出程度的影响。结果表明:综合考虑渗透率、相对渗透率曲线的时变特征,渗透率在水井附近迅速增加,并逐渐向油井方向扩展;相对高渗层的渗透率增加倍数高于低渗层的;综合含水率从80%到98%,相对高渗层的渗透率进一步增加的幅度较小,而相对低渗层的渗透率增加幅度较大;渗透率与相对渗透率曲线的时变特征使得层间采出程度差异扩大。

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

Calculating formula of relative permeability 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 permeability 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-permeability 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.