为考察暂堵绳结尺寸对封堵性能的影响,以可降解材料聚乳酸(PLA)、聚乙醇酸(PGA)熔融纺丝制备暂堵绳结,考察了暂堵绳结直径、尾翼长度和尾翼条数对其封堵性能的影响,并研究了PGA/PLA质量比对暂堵绳结降解性能和承压性能的影响。结果表明,在90℃条件下,随绳结尺寸增加封堵率整体呈先提高再稳定后降低的规律,当绳结直径大于18 mm、尾翼条数超过6条、尾翼长度在35~50 mm范围内时封堵性能最佳;绳结降解率随PGA/PLA质量比的增大而增大,绳结承压能力与PGA/PLA质量比成反比,当PGA/PLA质量比为80/20时,绳结在清水中26 h完全溶解,在0.1%滑溜水和30 000 mg/L的盐水中23 h降解率可达100%,承压能力在PGA/PLA质量比为50/50时可达50 MPa。

In order to investigate the effect of the size of the temporary plugging rope knot on the blocking performance,the temporary plugging rope knot was prepared by melt spinning of degradable materials,poly(lactic acid) (PLA) and poly(glycolic acid) (PGA),and the effects of the diameter of the temporary plugging rope knot,the length of the tails and the number of tails were investigated,and the effect of the mass ratio of PGA/PLA on the degradation and pressure-bearing properties of the temporary plugging rope knot was also investigated.The results show that,under 90℃,the blocking rate increases with the increase of knot size,and then decreases after stabilisation,and the best blocking performance is achieved when the diameter of the knot is larger than 18 mm,the number of tail strips is more than 6,and the length of the tail strips is in the range of 35-50 mm;the degradation rate of the knots increases with the increase of the mass ratio of PGA/PLA,and the pressure-bearing capacity of the knots is inversely proportional to the mass ratio of PGA/PLA.When the mass ratio of PGA/PLA was 80/20,the knot was completely dissolved in water for 26 h,and the degradation rate could reach 100% in 0.1% slippery water and 30 000 mg/L brine for 23 h.The pressure-bearing capacity of the knot could reach 50 MPa in the case of the mass ratio of PGA/PLA was 50/50.

郑健(1979-),男,硕士,高级工程师,主要从事地质勘探及压裂液新材料研究工作,通讯联系人,zheng_jian@petrochina.cn。