抗温耐盐型钻井液降粘剂合成与性能评价

Synthesis and performance evaluation of thinner for drilling fluid used at high temperature and salt

木质素磺酸钙、抗温耐盐型单体NS-1、丙烯酰胺(AM)和丙烯酸(AA)为原料,硝酸铈铵作为引发剂,用水溶液聚合的方法合成出接枝改性木质素磺酸钙钻井液降粘剂。其最优合成条件为:NS-1∶AA∶AM=3∶2∶2,木质素磺酸钙的用量为单体总量的50%,引发剂的用量占反应单体总质量的0.6%,反应温度为70℃,反应时间为2 h,单体的浓度为15%。当降粘剂的加量为1.5%,降粘率可达81.83%;在120℃的条件下,降粘率为61%;在Na Cl含量为10%的钻井液中,降粘率为60%;在Ca Cl2为1.5%的钻井液中,降粘率为62.86%。

The graft modification calcium lignosulfonate thinners for drilling fluid were synthesized by acrylamide（ AM）,acrylic acid（ AA）,sodium styrene sulfonate（ NS-1） and calcium lignosulfonate,using ammonium persulfate as initiator. Result showed that the optimum synthesis conditions were： monomer ratio of n（ NS-1） ∶ n（ AA） ∶ n（ AM） was 3 ∶ 2 ∶ 2,the concentration of calcium lignosulfonat was 50%,the reaction temperature was 70 ℃,the quality of monomer initiator（ ceric ammonium nitrate） was 0. 6%,reaction time was 3 h,monomer concentration was 15%. Adding 1. 5% copolymer viscosity reducer into fresh water base mud,the rate of reduction was respectively 81. 83% at 25 ℃ and 61% at 120 ℃; In the presence of concentration of Na Cl of 10% and Ca Cl2 of 1. 5% for the salt water mud,the rate of reduction were 60% and 62. 86%.