摘要
为了减缓酸岩反应速度,增大酸化半径,开展了硼酸在油田酸化解堵中的研究。根据缺电子化合物易形成配位络合物的原理,硼酸与氟能够形成配位数为4的BF4^(-)络合物,而BF4^(-)可缓慢水解产生氢氟酸,硼酸、盐酸及氟化铵可形成硼酸缓速体系。通过室内实验评价了硼酸缓速体系的性能指标:确定硼酸质量分数不超过3%;硼酸缓速体系较常规土酸酸化体系缓速明显,硼酸缓速体系的酸岩反应速度是常规土酸酸化体系的1/4;天然岩屑溶蚀性能与常规土酸酸化体系相当,破碎率降低50%以上;经硼酸缓速体系酸化后的岩心渗透率较常规土酸酸化体系酸化后提高60%以上。现场试验表明,用硼酸缓速体系酸化后增注效果显著,平均单井日增注13m3,有效期为125天。硼酸酸化技术已成为大庆油田不排液环保酸化的主流工艺技术。
With the purpose to slow down the acid rock reaction speed and increase the acidizing radius,the research on boric acid in oilfield acidizing plug removal was carried out.According to the principle that electron deficient compounds are prone to form coordination complex,boric acid and fluorine can form BF4^(-)complex with coordination number of 4,and BF4^(-)can hydrolyze slowly to produce hydrofluoric acid,boric acid,and hydrochloric acid and ammonium fluoride that can form boric acid retarded system.The property indicators of boric acid retarded system have been evaluated by laboratory experiments.The mass fraction of boric acid should be less than 3%.The acid rock reaction rate of boric acid retarded system is 1/4 that of conventional mud acid acidization system with obvious retardance reaction speed.The dissolution property of natural cuttings of boric acid retarded system is similar to that of conventional mud acid acidization system,and the crushing rate is reduced by more than 50%.The permeability of cores acidized by boric acid retarded system is improved over 60%higher than that of conventional mud acid acidization system.The field test shows that the stimulation effect is remarkable after acidizing with boric acid retarded system.The average daily injection increase of single well is 13 m3,and the effective period is 125 days.Boric acid acidizing technology has become the dominant technology of environmental protection acidizing without drainage in Daqing Oilfield.
作者
李胜利
李金禹
单永卓
孙文平
Li Shengli;Li Jinyu;Shan Yongzhuo;Sun Wenping(Production Technology Institute of Daqing Oilfield Limited Company;Heilongiang Provincial Key Laboratory of Oil and Cas Reservoir Stimulation)
出处
《采油工程》
2020年第3期29-32,79-80,共6页
Oil Production Engineering
关键词
硼酸
理化性能
缓速
溶蚀
破碎
岩心流动
boric acid
physical and chemical property
retardance
dissolution
crushing
core flow
