甲酸钾含量对氯化钠和硫酸钙溶解量的影响

Study on Influences of Formate Concentration on Solubility of NaCl and CaSO_4.

甲酸钾是钻井完井液的新型添加剂,具有抑制性强、高温稳定性和配伍性好、腐蚀性低、环境保护和油层保护性能好等优点。室内实验研究了甲酸钾浓度、溶解温度和溶解时间对氯化钠、硫酸钙溶解度的影响情况。结果表明:温度对硫酸钙在甲酸钾溶液中的溶解度影响较大,在同一浓度的甲酸钾溶液中硫酸钙溶解量随温度的升高而增加;温度对氯化钠溶解量的影响也很大,在同一浓度的甲酸钾溶液中氯化钠溶解量随温度的升高(从25 到65℃),先增加,到一个峰值后开绐降低,最后趋于某一恒定值;当甲酸钾溶液浓度低于20％时,硫酸钙溶解量随甲酸钾浓度增大而增加,当甲酸钾溶液浓度高于20％时,硫酸钙溶解量随甲酸钾浓度增大而减小,当甲酸钾浓度达到50％时,甲酸钾的浓度增加对硫酸钙溶解量的影响程度变小;在温度相同时,随甲酸钾浓度增加,氯化钠溶解量减小。

The study analyzed the influences of the farmate concentration on solubility of NaCl and CaCO4 and the results showed that in formate solution of determined concentration, the solubility of CaSO4 increases as temperature increases and solubility of NaCl increases in the temperature range of 25 - 65℃ then decreases after the curve apex and then decreases successively and approaches to a constant. As the formate concentration varies, solubility of CaSO4 increases with formate concentration increase when formate concentration is lower than 20% but it decreases with formate concentration increase after 20% and the influence of formate concentration becomes minor when formate concentration is higher than 50%. For NaCl, the solubility of NaCl decreases as formate concentration increase if the temperature is unchanged.