裂缝性油藏二次交联凝胶调剖体系的研究

Research on Two-step Crosslinked Gel Profile Control System Used in Fractured Reservoir

针对江苏杨家坝油田裂缝性油藏调剖中存在的高渗透和高滤失问题,室内研制开发了二次交联凝胶调剖体系,对其一、二次成胶性能进行了评价,确定了该体系的最佳配方:KYPAM(抗盐梳型聚丙烯酰胺)浓度为1 500—2 000 mg/L、KYPAM与 Cr^(3+)交联剂质量比为20:1～40:1、第二交联剂 BD 浓度为800～1 200 mg/L、热稳定剂 RW 浓度为5～10mg/L、体系 pH 值为9.0。结果表明,一次交联凝胶的形成对调剖剂原液在裂缝中的滤失具有很好的防护作用,二次交联凝胶体系可明显提高裂缝性油藏的采收率。

A two -step crosslinked gel profile control system was developed in laboratory for fractured reservoir of Yangjiaba Oilfield to resolve the problems of high permeability and high filtration. The first and secondary gelation properties of the system were evaluated. The optimum formula of the system was determined as follows ： KYPAM 1 500 - 2 000 mg/L, the ratio of KYPAM to Cr^3＋ crosslinker 20 ： 1 - 40 ： 1, the secondary crosslinker BD 800 - 1 200 mg/L, heat stabilizer RW 5 - 10 mg/L, pH 9.0. The evaluation results showed that first -step crosslinked gel prevented the profile control solution from filtration in the fracture well and the two - step crosslinked gel system increased the oil recovery ratio of the fractured reservoir obviously.