一种新型压裂液纳米助排剂的研制及性能评价

目的解决现有常规助排剂易被储层吸附、难以作用于较深储层孔隙的问题,以及现有纳米助排剂乳液粒径偏大,难以进入致密孔隙储层的问题。 方法通过相转变组分(PIC法)制备了一种新型纳米助排剂,该助排剂乳液粒径较小,表面张力较低且抗地层吸附特性突出。 结果该纳米乳液的粒径在100 nm以下,且长期保持稳定。以纳米乳液作为表面活性剂载体,在被吸附之后,表面张力为44.198 mN/m,接触角为93.08°；而相同配方的非乳液助排剂,在被吸附之后,表面张力为48.123 mN/m,接触角91.24°。计算毛细管阻力均为负数,表现为孔隙对液体的排斥力,纳米乳液的排斥力是非乳液的2.28倍。 结论该纳米乳液中残余的表面活性剂含量更高,更有利于抵抗储层的吸附,能作用于更深的储层孔隙,更利于孔隙排液,有效地解决了常规助排剂作用距离短的问题。 

Development and performance evaluation of a new nano-drainage aid for fracturing fluid

ObjectivesSolve the problems of existing conventional drainage aid are easy to be adsorbed by reservoir and difficult to act on deep reservoir pores, and the existing nano-drainage aid emulsion has a large particle size and difficult to enter tight pore reservoir. Methods A new nano-scale drainage aid was successfully prepared by phase inversion composition(PIC) method. The emulsion has a smaller particle size, lower surface tension and outstanding anti-formation adsorption property. ResultsThe experimental results show that the particle size of the nano-emulsion is less than 100 nm and remained stable for a long time. When using nano-emulsion as surfactant carrier, the surface tension is 44.198 mN/m and the contact angle is 93.08° after adsorption. While using the non-emulsion drainage aid with the same formula, the surface tension is 48.123 mN/m and the contact angle is 91.24° after adsorption. The calculated capillary resistance is negative, which is represented by the repulsive force of pores on the liquid. The repulsive force of nano-emulsion is 2.28 times that of non-emulsion. ConclusionsThe residual surfactant content in the nano-emulsion is higher, which is more conducive to resist the adsorption of the reservoir, act on the deeper pores of the reservoir, and is more conducive to the drainage of the pores, which effectively solves the problem of short distance of conventional drainage aid.