低渗透油藏反九点井网超前注水地层压力保持水平研究

Study on formation pressure maintaining level of advance injection in reverse nine point wel patern in low permeability reservoir

超前注水作为一种低渗透油藏的有效开发方式已被广泛认可,超前注水结束后,地层合理压力水平的确定是保证油田产量的关键,目前还没有理论公式作为支撑。本次研究通过理论公式推导了反九点井网,超前注水开发方式下的合理地层压力保持水平,该公式考虑了低渗透油藏启动压力梯度及介质变形现象,计算得出了不同压力系数、不同油藏深度条件下,超前注水合理的地层压力保持水平。通过已开发的超前注水示范区生产动态可以看出,该公式计算得出的地层压力保持水平具有较强的实际应用价值。分析该理论可知,对于压力系数小于1.0的油藏,为达到油藏平衡压力,可采用超前注水的开发方式,从而提高地层压力,改善低渗透油藏开发效果。

As an effective development method of low permeable reservoir,advanced water injection has been widely recognized,After the advanced water injection is over,The determination of reasonable pressure level is the key to ensure oilfield production,At present,there is no theoretical formula to support it.In this study,the inverse nine well pattern is deduced by theoretical formula,Reasonable formation pressure maintaining level under advanced water injection development mode,This formula takes into account the starting pressure gradient and the deformation of medium in low permeability reservoir,Different pressure coefficients and different reservoir depths are calculated,Reasonable formation pressure maintaining level of advanced water injection.Through the development of the advanced water injection demonstration area,we can see that,The formation pressure maintaining level calculated by this formula is of great practical value.Analysis of the theory can be seen,For reservoirs with pressure coefficients less than1,In order to achieve the reservoir equilibrium pressure,Development mode of advanced water injection can be adopted,So as to improve formation pressure and improve development effect of low permeability reservoir.