适合特低渗透油田的VES清洁压裂液性能

Performance Evaluation on VES Clean Fracturing Fluid Used for Ultra-low Permeability Oilfield

分析了VES清洁压裂液的黏弹性形成机理、抗剪切机理和破胶机理。室内实验表明,该清洁压裂液具有高弹性、低黏度的特性,其形成过程和流变性质对造缝、携砂、降低施工摩阻和控制缝高有重要的应用价值;稠化剂和激活剂之间有一个最佳比值;无机盐在较高的温度下不仅没有提高反而使得压裂液黏度降低,这是因为这些小分子在热运动中的剧烈振动,会增加对清洁压裂液中网络的破坏;复合物FH-1(30%C8醇和70%C10-14烷烃)可满足清洁压裂液在无烃类物质存在下的破胶,其可以有效控制清洁压裂液的破胶速度。该压裂液具有配液方便、使用添加剂种类少、不存在残渣等特点,采用内外相相结合的破胶剂可实现清洁压裂液在油层快速破胶排出地层,从而减少对地层伤害。

In this paper,the VES clean fracturing fluid system is analyzed,from the mechanisms with viscoelastic,anti-shear and gel breaking.The experimental results show that it has the characteristics of high elasticity and low viscosity,which are good for fracture initiation,carrying cuttings,decreasing lubrication and controlling fracture height.Meanwhile,there is a best ratio between viscosifier and activator,and the inorganic salts decrease the viscosity of fracturing fluid inhigh temperature.Moreover,the compound material FH-1 (30%C8 Alcohol and 70%C10-1 Alkane) can break gel with outhydrocarbon compounds and can control the breaking velocity of clean fracturing fluid.Furthermore,this fracturing fluidhas few additives,has no residue,and can be bled out of reservoir after gel breaking.