新型砂岩自转向酸体系的研究与应用

发布时间：2018-07-25 19:11

【摘要】：渤海主力油田储层层间渗透率级差大、非均质性强,酸化过程中酸液大量进入高渗层,引起渗透率级差进一步加剧,不能有效改善中低渗层,酸化解堵效果不理想。针对该问题,以新型两性离子表面活性剂ZX-1为稠化剂,优化形成了砂岩自转向酸体系,对该体系开展了流变性、配伍性、破胶性能、转向酸化效果评价实验。结果表明模拟鲜酸黏度6mPa·s,利于注入储层;模拟自转向酸变黏体系黏度60 mPa·s,耐剪切性强;模拟残酸黏度2 mPa·s,利于返排。自转向酸与缓蚀剂、铁离子稳定剂、防膨剂及助排剂配伍性良好,无沉淀、残渣产生;体系破胶容易,异丙醇、破乳剂、乙二醇丁醚及酸液消耗均能使自转向酸完全破胶,破胶后溶液黏度均低于10 mPa·s;体系具有自我清洁的作用,即使现场酸液未能完全破胶,经过一段时间能自动破胶,不会对储层造成永久性伤害。该自转向酸体系具有良好转向分流能力,随着初始渗透率级差从比2.00增大到10.70,酸化后低渗岩心渗透率改善倍数明显增大,高低渗岩心渗透率级差比减小,当渗透率级差达到10.7时,体系仍能实现有效分流酸化。ZX-1自转向酸现场应用效果明显,具有良好应用前景。
[Abstract]:In the main oil field of Bohai Sea, the permeability difference between layers is large and the heterogeneity is strong. During acidizing process, the acid liquid enters into the high permeability layer in large quantities, which causes the permeability difference to be further aggravated, and can not effectively improve the low and middle permeability layer, and the effect of acid plugging is not ideal. In order to solve this problem, a new amphoteric surfactant ZX-1 was used as thickener to optimize the formation of sandstone self-turning acid system. The rheology, compatibility, gel breaking performance and acidizing effect of the system were evaluated. The results show that simulating fresh acid viscosity 6mPa s is favorable to injection reservoir; simulating self turning acid viscosity system with viscosity 60 mPa s has strong shear resistance; simulating residual acid viscosity 2 mPa s is favorable for backflow. Self-turning acid has good compatibility with corrosion inhibitor, iron ion stabilizer, anti-swelling agent and drainage aid, no precipitation and residue production; the system is easy to break down, isopropanol, demulsifier, ethylene glycol butyl ether and acid consumption can all make the self-turning acid completely break gum, The viscosity of solution after gel breaking is lower than 10 mPa s, and the system has the function of self-cleaning, even if the acid in the field can not completely break the gel, it can break the glue automatically after a period of time, and it will not cause permanent damage to the reservoir. The self-turning acid system has good diversion ability. With the increase of initial permeability differential from 2.00 to 10.70, the permeability improvement multiple of low permeability core increases obviously and the permeability differential ratio of high and low permeability core decreases after acidizing. When the permeability difference reaches 10.7, the system can still realize the effective distributary acidification. ZX-1 self-turning acid field application effect is obvious, and has a good application prospect.
【作者单位】：中海石油(中国)有限公司天津分公司;石油工业出版社;
【分类号】：TE53

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