用氟硼酸酸化低渗砂岩地层的研究

STUDIES ON FLUOBORIC ACIDIZING TREATMENTS OF LOW PERMEABILITY SANDSTONE RESERVOIR

采用NH_4HF_2、H_3BO_3和HCl合成HBF_4,在大量室内研究的基础上提出了HBF_4酸液最佳配方。采用最佳配方进行酸化天然岩心的模拟试验,并考察了天然岩心在氟硼酸酸化前后的物性变化情况。介绍了氟硼酸酸化的现场施工程序与结果。室内及现场试验表明,氟硼酸对低渗砂岩储层的酸化是有效的,酸化效果较常规土酸的好。

The meehamisms of retarded acidizing by using fluoboric acid are discussed. The acid used in this study is prepared in-situ from NH_4HF_4, H_3BO_3 and HCl in proper proportions. A modeling acidizing test on natural cores using an optimum formulation is performed in laboratory, and the physical characteristics of the cores before and after the test are investigated. The procedure and results of fluoboric aeidizing operations at well sites are presented. Ladoratory and field tests show that fluoborie acid is applicable to acidizing in sandstone reservoir with low permeability, being more effective than mud acid in this case.