耐高温阴离子表面活性剂压裂液的性能评价及现场应用

PERFORMANCE EVALUATION AND FIELD APPLICATION OF HIGH TEMPERATURE ANIONIC SURFACTANT FRACTURING FLUID

针对国内清洁压裂液耐温性能普遍较差的问题,研发了可耐130℃高温的阴离子型表面活性剂压裂液体系。确定了该130℃高温压裂液体系的最终配方为4.0%D2F-AS11+0.6%KOH+3%KCl+0.2%EDTA。通过室内实验,研究了该压裂液体系的流变性、悬砂性、破胶返排性能、对基质的伤害性以及对裂缝内支撑剂导流能力的影响,实验结果表明,该体系耐温耐剪切性能良好,130℃、170 s-1剪切60 min,黏度一直保持在50 m Pa·s左右;破胶简单,可以用烃类和地层水来破胶,且破胶速度快,破胶后无残渣;对储层的基质渗透率伤害仅为9.8%,对裂缝内支撑剂的导流能力几乎没有伤害。现场试验表明,该阴离子表面活性剂压裂液体系施工摩阻低,携砂能力强,施工最高砂比达到42%,返排率达到82%以上,有利于对深井的加砂压裂改造。

Considering the poor heat resistance properties of clean fracturing fluid in China,an anionic surfactant fracturing fluid system available in 130℃ was developed. The final formula of the 130 ℃ high temperature fracturing fluid system was determined as 4. 0% D2F- AS11 + 0. 6% KOH + 3 % KCl+ 0. 2% EDTA. And its rheological properties,sand carrying capability,gel breaking and flowback performance,the damage to the substrate and the influence of fracture conductivity were studied by indoor experiments. The experimental results showed that the viscosity of the anionic surfactant fracturing fluid system was greater than 50 mP a·s after shearing 60 minutes under 170s- 1. The system could achieve the fast gel breaking with hydrocarbon and formation water,and there was no residue after gel breaking. Using this fracturing fluid,the matrix permeability of the reservoir damage was only 9. 8%,thus do little damage tofracture conductivity. Field test showed that this clean fracturing fluid had low friction and strong sand carrying capability. The sand ratio could reach 42% and the flowback rate was above82%. It is advantage to the sand fracturing of deep well.