摘要
为解除钻完井过程中引起的地层深部伤害,将缓速酸RE-Acid引入完井液体系中。缓速酸RE-Acid能够在低温下使得生成盐酸速率缓慢,在高温下使得溶液pH值迅速降低并可到达1以下,具有较强的溶蚀性,22%的缓速酸最终溶蚀率可达10%以上。在加重盐水完井液中,由于甲酸盐容易与Ca2+结合,甲酸钾延缓了缓速酸RE-Acid生成盐酸的速度,对CaCO3的溶蚀性能比其他盐溶液高,密度为1.3 g/cm3甲酸盐溶液中12%的缓速酸RE-Acid最终溶蚀率可接近20%。对低密度泡沫完井液,缓速酸RE-Acid对泡沫处理剂AFM-1的泡沫性能影响较小,且在该体系中仍然保持较好的溶蚀性能(可达到16%)。采用驱替实验表明,盐酸主要改造第一段岩心,第二段和第三段岩心渗透率增加幅度较小甚至有所降低;而缓速酸主要改造第二段和第三段岩心,使渗透率分别增加2.5倍和1.7倍,具有很好的深部改造作用。
The retarded acid （RE-Acid） is solved into the completion well fluid to relieve the deep damage in strata resulted from the drilling or/and well completion operations.The retarded acid （RE-Acid） slowly produces hydrochloric acid at low temperature and quickly lowers the solution pH value to less than 1 at high temperature with stronger dissolution performance.The dissolution rate of 22% concentration RE-Acid can reach more than 10%.For the well completion fluids added to salt,the potassium formate slows down the speed that RE-Acid generates hydrochloric acid because the formate can be easily combined with calciumion and unfolds better dissolution performance than the other salt solution.12% concentration RE-Acid can dissolve limestone with more than 20% dissolution rate in formate well completion fluid （weight：1.3 g/cm3）.For the low-density foam well completion fluid,AFM-1 foam agent has good properties in RE-Acid fluid.The RE-Acid dissolution rate is more than 16% for limestone in the AFM-1 foam basal agent fluid.The results of displacement experiments indicate that the hydrochloric acid only improves the permeability of the first segment core,but the retarded acid can improve the permeability of the second and third segment core in the deep,reaching more than 2.5 times and 1.7 times,respectively. Keywords：retarded acid; completion fluid; pH value; dissolution rate
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第2期177-180,共4页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
"十二五"国家重大专项(2011ZX05060-002)
关键词
缓速酸
完井液
PH值
溶蚀率
retarded acid
completion fluid
pH value
dissolution rate
