一种井壁稳定剂SACA-1的合成与性能评价

Synthesis and Performance Evaluation of a Borehole Stabilizer SACA-1

摘要: 在石油与天然气钻探过程中，如何保证破碎性地层的稳定一直是困扰钻井领域的一大技术难点。由于破碎性地层的特殊性，钻井过程中30%左右的井壁失稳问题发生在破碎性地层。室内选择N-乙烯基吡咯烷酮、2-丙烯酰胺基2-甲基丙磺酸(AMPS)、二甲基二烯丙基氯化铵、r-丙烯酸脂丙基三甲氧基硅烷等单体，优化合成条件，单体质量比4:2:1:1，单体浓度为30%，反应时间为4 h，反应温度为60℃，引发剂(过硫酸钾/亚硫酸氢钠)加量为0.5%，反应pH为8~9，合成了一种适合于破碎性地层的井壁稳定剂。对其分子结构进行了表征，分析了作用机理。性能评价结果表明，井壁稳定剂SACA-1抗温达到220℃，现场岩屑在3% SACA-1溶液中的热滚回收率为80.03%；在空气与水中联接后抗剪切强度分别为0.301 MPa和0.206 MPa，单轴抗压强度为8.47 MPa，3% SACA-1加入至聚磺钻井液和KCl-聚合物钻井液后，性能稳定，热滚回收率分别为85.8%和88.7%，对于破碎性地层有较好的稳定效果。

Abstract: In the process of oil and gas drilling, how to ensure the stability of fractured formations has always been a major technical difficulty in the drilling field. Due to the particularity of fractured formations, about 30% of the borehole instability problems occur in fractured formations during the drilling process. N-vinylpyrrolidone, 2-acrylamide 2-methylpropanesulfonic acid (AMPS), dimethyldiallylammonium chloride, r-acrylate propyltrimethoxysilane and other monomers were selected indoors, and the synthesis conditions were optimized, the monomer mass ratio was 4:2:1:1, the monomer concentration was 30%, the reaction time was 4 h, the reaction temperature was 60˚C, the initiator (potassium persulfate/sodium bisulfite) was 0.5%, and the reaction pH was 8~9, and a borehole stabilizer suitable for fractured formations was synthesized. Its molecular structure was characterized and the mechanism of action was analyzed. The performance evaluation results show that the temperature resistance of the borehole stabilizer SACA-1 reaches 220˚C, and the thermal recovery rate of on-site cuttings in 3% SACA-1 solution is 80.03%. After the connection between air and water, the shear strength is 0.301 MPa and 0.206 MPa, the uniaxial compressive strength is 8.47 MPa, and the performance is stable after 3% SACA-1 is added to the polysulfur drilling fluid and KCl-polymer drilling fluid, and the recovery rate of thermal roll is 85.8% and 88.7%, respectively, which has a good stability effect on the fractured formation.