水基钻井液复合成膜封堵剂的制备及性能

Preparation and performance of water-based drilling fluid composite film forming sealing agent

摘要:

以改性纳米二氧化硅SiO2作为刚性粒子，丙烯酰胺、2-丙烯酰胺基-2-甲基丙磺酸、苯乙烯和醋酸乙烯酯为聚合单体，OP-10和十二烷基磺酸钠为乳化剂，过硫酸铵和亚硫酸氢钠为引发剂，合成了一种有机-无机复合成膜封堵剂。采用FTIR、TGA、DLS和SEM对产物的形貌、结构进行了表征。研究了该封堵剂对水基钻井液的流变性、滤失性及封堵性能的影响。结果表明，复合成膜封堵剂呈球状，并保持纳米级分布。温度为340 ℃时，质量损失约为总质量的14%。120℃，16 h老化后较老化前粘度性能增加，封堵剂加量为3%时（以体系总质量计，下同），API滤失量为10 mL。当封堵剂加量大于2%，砂床滤失量为0 mL。加量为4%时，高温高压滤失从104 mL减小至29 mL，封堵率为90.7%。

Abstract:

A organic-inorganic composite membrane sealing agent was synthesized using modified nano SiO2 as rigid particles, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, styrene, and vinyl acetate as polymerization monomers, OP-10 and sodium dodecyl sulfonate as emulsifying agents, and ammonium persulfate and sodium bisulfite as initiators. The morphology and structure of the product were characterized using FTIR, TGA, DLS, and SEM. The effects of the sealing agent on the rheological properties, filtration properties, and sealing performance of water-based drilling fluids were studied. The results indicate that the composite film-forming sealing agent is spherical and maintains a nanoscale distribution. At a temperature of 340 ℃, the mass loss is approximately 14% of the total mass. After aging at 120 ℃ for 16 hours, the viscosity performance increases compared to before aging. When the amount of sealing agent added is 3% (based on the total mass of the system, the same below), the API filtration loss is 10mL. When the dosage of sealing agent is greater than 2%, the filtration loss of the sand bed is 0mL. When the dosage is 4%, the high-temperature and high-pressure filtration loss is reduced from 104 mL to 29mL, and the sealing rate is 90.7%.