弱凝胶钻井液成胶剂AM/AMPS/OA_8的合成与表征

针对水平井、大斜度井钻井过程中井眼润滑性、岩屑携带以及钻井速度的影响等问题,通过合理的分子设计,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和实验室自制疏水单体丙烯酸正辛醇OA_8为原料,利用胶束聚合法,制备了一种弱凝胶成胶剂AMAMPSOA_8,其结构经1H NMR和IR表征。以AMAMPSOA_8在低剪切速率下的表观粘度为指标设计正交试验,确定最优反应条件为:AM与AMPS摩尔配比为4.8∶1,引发剂用量为单体总质量的0.04%,疏水单体浓度为0.75%,于70℃反应9 h。该条件下,0.5%AMAMPS0A_8聚合物溶液在低剪切速率3 r·min~(-1)下表观粘度可达23 680 mPa·s。利用热分析仪、高温滚子炉、高温高压流变仪对产物性能进行了研究。研究表明:AMAMPSOA_8的抗温性能可达160℃;聚合物溶液体系有明显的触变性,在40 min后溶液切力增加幅度变缓。

Synthesis and Characterization of A Weak Gel Gelling Agent AM/AMPS/OA8 in Water-based Drilling Fluid

Facing with the problems of borehole lubrication , cuttings transportation and drilling speed in the drilling processes of horizontal wells and highly-deviated wells, a kind of weak gel gelling agent ( AMAMPSOA8 ) was successfully synthesized by reasonable design of molecular structure and micellar polymerization, using acrylamide(AM), 2-acrylamide-2-methylpro panesulfonic acid(AMPS) and the hydrophobic monomer OA 8 which was made in laboratory as raw materials .The structure was character-ized by 1 H NMR and FT-IR.Setting the apparent viscosity of AMAMPSOA8 at the low shear rate as in-dex, orthogonal experiments were designed to determine the optimal reaction conditions:molar ratio of AM and AMPS was 4.8:1 , the mass fraction of initiator was 0.04%, the concentration of hydropho-bic monomer was 0 .75%, reaction at 70 ℃ for 9 h.Under this condition , the apparent viscosity of AMAMPSOA8 at the low shear rate (3 r· min-1 ) was 23680 mPa· s.The performance was studied by the thermal analyzer , high temperature roller furnace and HAAKE rheometer .The results showed that the polymer solution system exhibited obvious thermal property up to 160 ℃and thixotropic property , the shear strength increased slowly after 40 min.