萨中开发区不同开发阶段砂岩储层参数变化规律研究

STUDY ON HOW SANDSTONE RESERVOIR PARAMETERS CHANGE AT DIFFERENT DEVELOPMENT STAGES AT SAZHONG DEVELOPMENT AREA

为确定萨中开发区长期开发过程中储层参数的变化规律,指导油田数值模拟及开发调整,综合萨中开发区不同时期的32口取心井资料利用数学地质方法分析了不同开发阶段储层参数的变化情况,建立了水驱、聚驱不同含水饱和度条件下渗透率的预测模型。在不同开发阶段,孔隙度变化很小,其他储层参数主要受水洗程度和储层性质影响。当储层孔隙度小于20%时,不同时期各参数变化不大。储层孔隙度大于20%时,水驱过程中,随孔隙度、水洗程度增加,渗透率、平均孔径先增大后减小,分选性、连通性变好;聚驱过程中,中等水洗程度时,储层的渗透率、平均孔径随孔隙度增加先减小后增加,连通性先变差后变好,其它水洗程度下,各参数变化规律与水驱阶段各参数变化规律基本一致。

In order to determine the variation rule of reservoir parameters during the long-term development process at Sazhong Development Zone,and in order to guide the numerical simulation and development strategy adjustment for the oil field,the data of 32 cored wells at different periods in that area have been synthesized,the variation rule of reservoir parameters at different stages of development is studied by mathematical geological analysis,and the permeability prediction models are established for different water saturation conditions during water flooding and polymer flooding.At different development stages,porosity changes little,and other reservoir parameters are mainly affected by water flush degree and reservoir properties.When the reservoir porosity less than 20%,there is little change in the parameters at different stages.When reservoir porosity greater than 20%,permeability and average pore diameter increase first and then decrease with increase in porosity and water flush degree,and sorting and connectivity become well.In polymer flooding,at medium water washing degree,permeability and average pore diameter of reservoir decrease first and then increase with porosity increasing,and connectivity becomes worse first and then changes well later;while under other flush degree,the variation rule of each parameter is basically the same as that during water flooding stage.