海上油田二元驱后残留聚合物再利用技术研究

Study on Technology of Reusing Residual Polymer After Binary Flooding in Offshore Oilfield

海上J油田开展二元复合驱取得了较好的效果,目前已进入方案实施后期,分析产聚浓度可知,大量聚合物因吸附滞留残留在地层中,因此开展二元驱后残留聚合物再利用技术研究,实现二元驱后进一步提质增效。结果表明,二元复合驱后剩余油分布更加零散,多位于边角部位,主要富集在渗透率相对较低、厚度相对较大的层位。改性酚醛树脂交联剂C与聚合物配伍性最好,在聚合物浓度为400 mg/L时,1000 mg/L交联剂C与1000 mg/L助交联剂复配,体系交联强度能达到27000 mPa·s以上,形成高强度凝胶。驱油实验结果表明,应用残留聚合物再利用技术,在聚合物驱基础上注入0.2PV固定剂,可进一步提高采收率3.28%。

The binary compound flooding in offshore J oilfield has achieved good results,and now it has entered the later stage of the implementation of the scheme.According to the analysis of the concentration of polymer production,a large number of polymers were retained in the formation due to adsorption,so the residual oil distribution and residual polymer reuse technology after binary flooding were studied to further improve the quality and efficiency after binary flooding.The results showed that the remaining oil after binary compound flooding was more scattered,mostly located in the corner,mainly concentrated in the layer with relatively low permeability,weak washing and non-washing,relatively large thickness.Crosslinking agent C had the best compatibility with the polymer,and could form high-strength gel at a wide concentration of 500~1000 mg/L.When the polymer concentration was 400 mg/L,1000 mg/L crosslinking agent C was combined with 1000 mg/L crosslinking agent,and the crosslinking strength of the system was more than 27000 mPa·s.Oil displacement experiment results showed that the recovery of 3.28%could be improved by injecting 0.2 PV fixed agent on the basis of polymer flooding using residual polymer recycling technology.