陈堡油田油井自转向酸化解堵试验研究

Study on plugging removal by self-diverting acidization for Chenbao Oilfield

针对陈堡油田供液变差井酸化改善效果有限的问题,采用自转向酸酸化技术以实现酸化过程中酸液自动转向和深部穿透的目的,且酸化后遇烃自动破胶,返排彻底,无二次伤害,可以高效、均匀地酸化储层。通过缩合反应和季铵化反应合成出了一种具有自转向性能的粘弹性表面活性剂,并通过实验评价了浓度、p H值、温度等因素对该自转向剂粘度的影响。优选陈堡油田主力单元水平井进行自转向酸化解堵试验,取得很好的增油效果。

To solve the problem of limited effect in conventional acidizing for wells with low fluid production in Chenbao Oilfield,the self-diverting acidization technology was proposed. The self-diverting acid fluid can automatically redirect and penetrate deeply target layers in the process of acidizing. The gelatinous self-diverting acid can be broken by contacting hydrocarbon after acidizing. And then the reacted acid can flow back easily without residuals and secondary damage. As a result,the target formation can be homogeneously and effectively acidized by the self-diverting acidization technology. A kind of viscoelastic surfactant with self-diverting property was developed through condensation reaction and quaterisation reaction. It was carried out evaluation on the effect of concentration,p H value and temperature on the viscosity of self-diverting acid fluid. The technology was implemented in horizontal well in Chenbao Oilfield. The obvious oil increasing oil effect was obtained.