STP强凝胶调剖剂的深度调剖性能

The performance of STP hard-gel in deep profile controlling

STP强凝胶调剖剂由聚丙烯酰胺、交联剂和延缓剂组成。用人造岩心进行凝胶性能实验,55℃时成胶时间为72h,岩心封堵率大于99.9%,注水50PV冲刷后封堵率仍不低于99.8%,突破压力梯度在高渗透率(5.62D)岩心中不低于4.45MPa/m,在低渗透率(0.57D)岩心中为3.46MPa/m,有一定的选择性。分别串联3支高渗透率岩心和3支低渗透率岩心,将二者并联构成非均质模型,饱和原油进行调剖驱油实验,未注调剖剂时的水驱合层采收率为24.3%,用调剖剂依次封堵第一、第二、第三高渗透率岩心后,水驱合层采收率分别达到46.8%、62.2%和69.1%,表明逐步增大封堵深度可以进一步提高油层采收率。STP强凝胶调剖剂在大庆油田萨中开发区的实际应用取得了明显成效。

STP profile control hard-gel is made up of polyarylamide, cross-linking agent and retardant. The gel performance experiments were conducted with man-made cores, the gelation time was 72h at 55℃, the blocking coefficient was larger than 99.9% and it was not less than 99.8% after being flushed with 50 PV injected water. The breakthrough pressure gradient was not lower than 4.45MPa/m in high-permeability cores (5.62D) and it was 3.46MPa/m in low-permeability ones (0.57D), which shows some selectivity. Three high-permeability cores and low-permeability ones were connected in tandem, respectively; both were paralleled to form the heterogeneous model. The model was saturated with oil and profile controlling experiments were carried out, in which the total water-flood recovery was 24.3% in case of that no profile control agent was injected. The first, second and third high-permeability cores were sealed in turn by using the profile control agent, the total recovery reached 46.8%, (62.2%) and 69.1%, respectively, which indicated that the recovery could be further enhanced as the sealed depth increases.The application in the exploiting zone of Daqing Oilfield is apparently effective.