鄂南浅层油气藏低伤害VES-M清洁压裂液研究

摘要

With guar gum,synthetic polymers and the viscoelastic surfactant as thickeners,a low damage VES-M clean fracturing fluid system adapted to shallow reservoirs has been optimized.The temperature resistance,sand suspension ability,viscosity break and the influence on core permeability of this system were evaluated.The results indicate that the apparent viscosity of VES-M clean fracturing fluid system reaches 50 mPa · s under the condition of 60 ℃ and 170s-1,and the fracturing fluid has a better sandcarrying performance.The fracturing fluid gelout better confronting water or hydrocarbons and the viscosity of gel breaking liquid is less than 5 mPa · s.There is little residue and damage to formation and it is easy to flow back.The field applications of shallow oil and gas fields in E'nan area show that the clean fracturing fluid has better gel breaking performance,low friction,little damage to formation.It could be seen that fracture height was controlled effectively and the production can be increased significantly.%以瓜胶、合成聚合物以及粘弹性表面活性剂等为稠化剂,优选出一种适应浅层油气藏的低伤害VES-M清洁压裂液体系.综合评价了压裂液体系热稳定性、悬砂性、破胶性能以及对岩心渗透率的影响.结果表明,VES-M清洁压裂液体系在60℃,170 s-1条件下的表观黏度达50 mPa·s,悬砂性能良好,遇水或者烃类均可破胶,破胶后粘度低于5 mPa·s,无残渣,对地层伤害小且易返排.鄂南浅层油气藏的现场应用表明,该清洁压裂液具有良好的破胶性能、摩阻低、伤害小,可有效控制缝高,增产效果明显.