为了进一步改善低渗透油藏非均质储层的注水开发效果,应用油藏工程方法研究了渗透率非均质性与注水开发井网几何形式的耦合作用,引入了渗流因子及渗流因子变异系数,提出了低渗透油藏非均质储层注水井偏移的井网调整新方法,并应用黑油模型数值模拟技术对其进行了适应性评价。将注水井沿井排方向偏移一定距离,井组内渗流因子变异系数降低,且随着砂体渗透率级差的增大、井网内横切比的减小,注水井向低渗砂体方向的偏移距离逐渐增大。注水井偏移最佳距离后,井组产油能力提高了5.6%,含水率下降了3.7%,明显提高了水驱开发效果。提出的非均质性评价方法及注水井最佳偏移量计算式,为低渗透非均质储层注水开发时的井网调整提供了新思路。
To improve water flooding results in low permeability reservoirs,a new approach used to i- dentify heterogeneous formations for well pattern adjustment was proposed in this paper. The coupling effect of permeability heterogeneity and the geometry of water flooding well pattern had been studied by u- sing reservoir engineering method. In the research, two new factors, seepage factor and variable coefficient of seepage factor, were introduced, then the new method for well pattern adjustment and injector offset were derived from the analysis of the seepage process, its adaptability was evaluated by black oil numerical simulation. The variable coefficient of seepage factor decreases as the increase of injector offset from the o- rientation of well row. Furthermore, the distance of injector offset is going to be longer as the crosscutting ratio of well pattern goes down and the permeability difference of sand body rises. The production of the well group increased 5.6% and water cut decreased 3.7% after the optimal distance of injector offset,re- sulting in a significant improvement in water flooding. The proposed approach for heterogeneity evaluation and the formula calculating optimal injector offset provide new ways for well pattern adjustment in hetero- geneous and low permeability reservoirs.