适合海上某油田注水开发的水质指标优化研究

Optimization of water quality indicators suitable for water injection development in a certain offshore oilfield

为了提高海上油田注水开发的效率,降低注入水对储层造成堵塞污染的风险,采用不同渗透率的人造岩芯对适合海上某油田注水开发的水质指标进行了优化研究,主要包括悬浮物含量、悬浮物粒径和含油量。实验结果表明,对于渗透率为40m D左右的注水层,推荐注入水的综合水质指标为SS(悬浮物含量)=1.5mg·L^(-1),D(悬浮物粒径)=1.5μm,O(含油量)=2.0mg·L^(-1)或者SS=1.0mg·L^(-1),D=1.5μm,O=4.0mg·L^(-1),此时人造岩芯驱替200PV后的渗透率保留率分别为84.87%和83.70%;而对于渗透率为100m D左右的注水层,推荐注入水的综合水质指标为SS=3.0mg·L^(-1),D=2.0μm,O=4.0mg·L^(-1)或者SS=2.0mg·L^(-1),D=2.0μm,O=6.0mg·L^(-1),此时人造岩芯驱替200PV后的渗透率保留率分别为82.48%和83.50%。研究结果可为海上油田注水开发水质指标的制定提供参考。

In order to improve the efficiency of water injection development in offshore oilfield and reduce the risk of reservoir blockage and pollution caused by injected water,artificial cores with different permeability were used to optimize the water quality indicators suitable for water injection development in a certain offshore oilfield,mainly including suspended solids content,suspended solids particle size,and oil content.The experimental results indicate that for an injection layer with a permeability of about 40mD,the recommended comprehensive water quality indicators for injection are SS(suspended solids content)=1.5mg·L^(-1) and D(suspended solids particle size)=1.5μm,O(oil content)=2.0mg·L^(-1) or SS=1.0mg·L^(-1),D=1.5μm,and O=4.0mg·L^(-1),the permeability retention rates of the artificial core after displacement of 200PV are 84.87%and 83.70%,respectively;For injection layers with a permeability of around 100mD,the recommended comprehensive water quality index for injection are SS=3.0mg·L^(-1) and D=2.0μm.O=4.0mg·L^(-1) or SS=2.0mg·L^(-1),D=2.0μm,and O=6.0mg·L^(-1),at this time,the permeability retention rates of the artificial core after displacement of 200PV are 82.48%and 83.50%,respectively.The research results can provide reference for the formulation of water quality indicators for offshore oilfield water injection development.