一种海水基清洁压裂液体系研究

The Formulation and Properties of on a Seawater-Based Clean Fracturing Fluid

林波 刘通义 陈光杰

LIN Bo LIU Tongyi CHEN Guangjie

以丙烯酸、丙烯酰胺、阳离子不饱和单体、阴离子不饱和单体等为主要聚合单体，十二烷基苯磺酸钠为乳化剂，过硫酸铵- 亚硫酸氢钠为引发剂，制得水溶性聚合物稠化剂BCG-1。该稠化剂能在海水中具有良好的增黏能力，0.6% BCG-1 海水溶液的表观黏度大于80mPa·s。与相关添加剂按组成为0.6％BCG-l+0.4％金属离子螯合剂BCG-5 + 0.3％黏度增效剂B-55+ 0.1% 温度稳定剂B-13+ 0.02% ～0.05% 胶囊破胶剂BCG-10配制的压裂液30℃下放置一周，表观黏度变化较小，无沉淀产生，常温稳定性良好。该压裂液在170 s-1、140℃下剪切60min后的黏度为46.9 mPa·s，耐温耐剪切性较好；落球黏度为4534.7 mPa·s，携砂性较好；破胶彻底，残渣含量小于5 mg/L，破胶液表面张力小于26mN/m，破胶液对支撑裂缝导流能力的伤害低于8% ，具备清洁压裂液的性能特性。图5 表6 参12

A water-soluble polymer thickener BCG-1 was synthesized by using acrylic acid，acrylamide，cationic unsaturated monomer and anionic unsaturated monomer as mainly polymeric monomers，sodium dodecyl benzene sulfonate as emulsifier and ammonium persulfate-sodium bisulfite as initiator system. BCG-1 could be able to swell in seawater ，and the apparent viscosity of seawater solution with BCG-1 dosage of 0.6% was greater than80mPa·s. The seawater-based fracturing fluid was prepared by using the thickener and other related additives ，the formula was obtained as follows: 0.6% BCG-l+0.4% metal ions chelating agent BCG-5 + 0.3% viscosity synergist B-55+ 0.1% temperature stabilizer B-13+ 0.02%～0.05% capsule gel-breaker BCG-10. The fracturing fluid had no precipitation and the apparent viscosity changed little after being laid up for a week at 30℃，indicating a good stability at normal temperature. The viscosity of the fracturing fluid remained at 46.9 mPa·s after shearing at 170 s-1and 140℃for 60minutes，showing good temperature and shearing tolerance. The falling ball viscosity was 4534.7 mPa·s，showing goodcarrying capacity. And it could be completely gelout，the content of residue was less than 5 mg/L. The surface tension of broken gel liquid was less than 26mN/m. The damage of broken gel liquid on flow conductivity of support crack diversion was below8% ，which completely possessed the performance characteristics of clean fracturing fluid.