流体压缩性和压敏性对低渗油藏产量的影响

Influence of Fluid Compressibility and Stress Sensitivity on Oil Well Productivity

针对低渗油藏的特性,推导出考虑启动压力梯度和流体压缩性的应力敏感油藏的质量流量公式,利用质量与密度关系式得到相应的体积流量公式。计算表明:考虑应力敏感性时,油井产量不再随着生产压差的增加而呈正比例增加;当储层呈现强应力敏感特性时,油井产量随生产压差的加大而增加缓慢,此时需要优化出合理的生产压差。考虑流体压缩性时,油井产量随着流体压缩系数的增大而增大。相对误差随压差的增大呈直线递增,故不能忽略流体压缩性的影响。在工程上,只有当生产压差足以克服启动压力梯度的阻碍效应时,油井才能快速见到产量。

Based on low permeability,the mass flow formula of considering start-up pressure gradient and fluid compressibility in stress sensitivity reservoir is obtained.And then the corresponding volume flow formula is obtained by using the relation formula of the quality and density.Calculation shows when stress sensitivity is considered,well production no longer increase in direct proportion with the increase in the pressure differential.When the reservoir presents a strong stress sensitivity characteristics,well production increases slowly with the increase of the differential pressure.We need to optimize the reasonable production pressure difference.Considering the fluid compressibility,well production increases with fluid compression factor increases.The relative error with the pressure increase in a linear increase,it can not ignore the impact of fluid compression.In engineering,only when the production pressure difference is sufficient to overcome the obstacles of start-up pressure gradient effect,just have the production in engineering.