注水过程中储层深部污染的试井诊断及应用

注水开采原油是目前普遍采用的采油方式,它对保持油层压力,实现油田高产稳产、高效开发发挥着重要的作用。注水过程中由于注入水向地层推进,在储层内会发生物理的或化学的反应,从而导致储层中流体渗流阻力增加和渗透率下降,造成地层污染。通常,人们通过试井手段来进行储层污染评价,但仅限于井筒周围附近地带,试井得到的地层参数反映的也只是近井地带的性质。对于深部储层特性,特别是储层深部污染的诊断却没有深入的研究。从典型的实例出发,分析了储层深部污染在试井曲线上的反映,并定性分析了储层深部污染的原因,得出了用试井手段评价注水过程中对储层深部伤害的方法。实践证明,这种方法切实有效,能有效指导油田注水开发,改善油田注水开发效果。

THE EVALUATION OF DEEP INNER FORMATION DAM AGE THROUGH TRANSIENT TEST DIAGNOSIS CURVE

Water injection is a commonly used way to develop oil field, which can maintain reservoir pressure to ensure steady wellhead oil rate. In the process of waterflooding, there may occur physical or chemical reaction between the injected water and reservoir porous media, which would result in the increaseof fluid flow resistance and the reduction of reservoir permeabili-ty. In general, the formation damage is evaluated by transient test, which only reflects the damage of neighborhood wellbore while as for deep inner formation damage there were few further researches published. We analyzed the characteristics of deep inner formation damage on transient test curves based on thetypical example data .The factors leading to formation damage were also studied. Thus, we found the method to evaluate deep inner formation damage by transient test data. This method has been proven practical in guiding water injection operation.