聚合物单管多层分质分压注入技术

Polymer separate injection technology with separate mass and pressure

大庆油田主力油层聚驱结束后,二、三类油层分注面临着中、高分子量聚合物对部分油层适应性较差,注入溶液主要流向油层性质好、连通好的油层,薄差层动用程度低的矛盾。为了解决层间矛盾,提高最终采收率,提出了聚合物单管多层分质分压注入技术。介绍了研发的分子量调节器和压力调节器;对应低渗透层使用分子量调节器,高渗透层使用压力调节器,实现对分子量和注入量的双重控制;在不影响高渗透层聚驱效果的同时,通过对分子量的剪切降解作用,有效增加了聚合物分子可进入低渗透油层的孔隙体积。通过对现场试验资料分析,分质分压注入井与正常分层注聚井对比,剖面动用明显提高。聚合物单管多层分质分压注入技术可满足大庆油田二、三类油层聚合物驱分层注入的需要。

When the main reservoir groups of Daqing Oilfield are after polymer flooding, the mid and high molecular polymer in class II and III reservoirs will have poor adaptability to some reservoirs, injected solution will flow into other reservoirs with good property and connectivity, and the thin and poor layers of them are hardly produced. To solve these problems and improve the ultimate recovery rate, this paper puts forward the polymer separate injection technology with separate mass and pressure. It introduces the molecular regulator and pressure regulator, which will be applied to low-permeability and high-permeability reservoirs separately, so as to realize the dual control on molecular weight and injection rate. Based on keeping the polymer flooding effect of high-permeability reservoirs, the molecular is degraded and shorn to increase the pore volume that permits the polymer molecular to enter into the low-permeability reservoirs. The data obtained from the field test show that the polymer injection technology with separate mass and separate pressure can more increase the profile producing degree than the conventional layering polymer flooding technology. It can meet the demand of the class II and III reservoir in the oilfield for polymer separate injection.