基于驱替定量表征的高含水油田注水井分层配注量确定方法

多层合采油藏进入高含水期之后，由于层间驱替程度差异加大，导致常用分层配注方法的效果变差。为此，在分析多层合采油藏长期注水开发特点的基础上，提出采用驱替通量定量表征各层驱替程度差异的方法，并以均衡驱替为目标，综合考虑储层厚度、孔隙度、注水历史、调控周期等因素的影响，建立了基于驱替通量均衡化思想的注水井纵向各层配注量确定方法。运用精细油藏数值模拟方法分析了厚度法、地层系数法、剩余油法和基于驱替定量表征的均衡驱替方法在不同含水阶段的适应性。数值模拟结果显示，含水率小于50%时，推荐采用厚度法；含水率为50%~80%时，推荐采用剩余油法；含水率为80%~90%时，推荐采用均衡驱替法。渤海SZ油田X1井组在高含水期采用均衡法调整配注量，调整后井组平均含水率下降4%，日增油117 m3，降水增油效果显著。研究结果表明，基于驱替定量表征的分层配注量确定方法可用于指导高含水期多层合采油藏注水井各层配注量的调整。 

A Method to Determine the Layered Injection Allocation Rates for Water Injection Wells in High Water Cut Oilfield Based on Displacement Quantitative Characterization

After reservoirs with multi-layer commingled production enter the high water cut stage,the interlayer displacement disparity is increased and the effect of commonly used layered injection allocation method is deteriorated.Through the analysis of the characteristics of long-term water flooding in reservoirs,a quantitative characterization method using displacement flux to describe the displacement disparity among each layer was put forward.Aiming at balancing the displacement,a new method was established to determine the injection allocation rates for water injection wells based on the idea of displacement flux balance,which took into consideration the influence of reservoir thickness,porosity,water injection history and adjustment cycle.The fine reservoir numerical simulation technique was used to analyze the adaptability of thickness method,formation coefficient method,remaining oil method and the new method at different water cut stages.Numerical simulation results showed that the thickness method is to be recommended when the water cut is less than 50%.When the water cut is from 50% to 80%,the remaining oil method is recommended,and when the water cut is in the range of 80%-90%,the new method can be recommended.The new method was applied to the well group X1 in the Bohai SZ Oilfield as the pilot test and had significant effect,with the average water cut decreased by 4% and daily oil production increased by 117 m3.The research results indicated that the new layered injection allocation method with displacement quantitative characterization could be effective in guiding the optimization and adjustment of the allocations rates in reservoirs under high water cut stage.