低伤害低腐蚀的无固相修井液体系研制与性能评价

Development and Performance Evaluation of a Solid-free Workover Fluid System with Low Damage and Low Corrosion

何 腾 刘建仪 贾春生 刘 洋 李 函

HE Teng LIU Jianyi JIA Chunsheng LIU Yang LI Han

在南海西部油田修井作业过程中， 修井液滤失进入地层造成储层伤害。为解决现场修井液对管材腐蚀严重、 易引发黏土水化膨胀、 降低储层渗透率等问题， 研制了一种低伤害低腐蚀的新型无固相修井液， 对黏土防膨剂、 助排剂和弱酸 MHA进行了筛选， 确定了修井液体系的最佳配方， 研究了修井液的缓蚀性和对岩心渗透率的影响。结果表明， 修井液体系组成为过滤海水、 5%有机盐黏土防膨剂 TFB-2、 0.5%黏土防膨剂 HAS、 1% MHA、0.5%助排剂 FC310时可有效抑制黏土水化膨胀， 其黏土防膨率（约 90%）大于现场修井液（70%）； 对管材的腐蚀速率低， 70℃下对钢片的腐蚀速率为 1.2361 g/ （m2· h）， 仅为现场修井液的 43.8%； 新型修井液可提高岩心渗透率，处理岩心后的岩心渗透率恢复率约为 110%， 大于现场修井液的 70%。新型修井液油水界面张力低、 易于返排，可有效提高近井地带的储层渗透率， 性能优于现场修井液。图7表5参14

During the workover treatment process in western oilfield of the South China Sea，the workover fluid infiltrated into reservoir causing reservoir damage. In order to improve the corrosion resistance of pipe，suppress the hydrate swelling of clay and reduce the permeability of reservoir，a solid-free workover fluid with low damage and low corrosion had been developed. By screening clay stabilizer，drainage aid and weak acid MHA，the optimum prescription of workover fluid system was determined. And the corrosion resistance of workover fluid and the effect on the core permeability were studied. The results showed that the workover fluid system，which was composed of filtered seawater，5% organic salt clay anti-swelling agent TFB-2，0.5% clay anti-swelling agent HAS，1% MHA and 0.5% discharge aiding agent FC310，could effectively inhibit clay hydration expansion and the clay expansion rate of prevention was about 90% which was greater than that of field workover fluid（70%） . The new workover fluid system had a low corrosion rate，and the corrosion rate of steel sheet was 1.2361 g/ （m2·h）at 70℃，only 43.8% of the field workover fluid. New workover fluid could improve the core permeability. The core permeability recovery rate of new workover fluid was about 110%，more than that of field workover fluid（70%） . New workover fluid had a low oil-water interfacial tension and was easy to flow back，which could effectively improve the permeability of reservoir near wellbore area，and the performance was superior to that of field workover fluid.

10.19346./j.cnki.1000-4092.2017.01.002