薄差储层有效驱替理论与应用

应用油藏工程方法,综合考虑驱替压力梯度和启动压力梯度的影响对薄差储层有效驱替理论进行研究.根据不等产量一源一汇驱替压力梯度公式,分别得到地层压力、注入压力、井底流压以及井距变化时的驱替压力梯度图版,并分析其变化规律;根据岩心水动力实验结果,建立启动压力梯度与渗透率的关系,分析有效驱动不同渗透率的储层所需要的驱替压力梯度临界值.研究表明:驱替压力梯度大于最大启动压力梯度是薄差储层有效驱替的必要条件;小井距是薄差层有效驱动的最优选择;可以通过措施和注采压力系统调整达到驱替压力梯度高于最大启动压力梯度的目的,从而有效驱动薄差储层.研究对薄差储层开采具有重要的指导意义,并在矿场试验中得到了有效论证.

Study and Application on the Theory of Effective Displacement in Thin and Poor Pay Zone

Through the theory and method of reservoir engineering,considering the impact of displacement pressure gradient and the threshold pressure gradient to conduct a research on the theory of effective displacement in thin and poor pay zones comprehensively.According to the pressure gradient formula of unequal production diverging/converging system,making displacement pressure gradient charts varied with formation pressure,injection pressure,bottom hole flowing pressure and the producer injector spacing,analyzing the change rules as well.Using core hydrodynamic experiment results,setting up the relationship between threshold pressure gradient and permeability,and analyzing the critical value for effective displacing pressure gradient of permeability at different levels.Study shows that it is a necessary condition for effective displacement that the displacement pressure gradient is greater than the maximum threshold pressure gradient in low permeability reservoir.Small well spacing is the best choice for effective displacing.It can be achieved through taking measures and the adjustment of injection-production pressure system to make the displacement pressure gradient higher than the maximum threshold pressure gradient.Thus,it can effectively drive the thin and poor formation.The study is of great significance for the exploitation of thin and poor reservoir,and it has made a great difference in field experiment.