Stimulation Effect Of Hydraulic Fracturing Improved By Environment-friendly Microemulsion

Based on biodegradable fatty acid methyl ester sulfonate (MES) and bio-diesel as the main raw materials, the reasonable formula of environment-friendly middle phase microemulsion is optimized by the orthogonal test. The microemulsion system changes from Winsorâ… type toâ…¢type andâ…¡type with the sanning of NaCl and n-butanol concentrations, the solubilization parameter of water deceases and the solubilization parameter of oil increases; the value of the optimal salinity and the length of salinity decrease and the solubilization of microemulsion increases with the increasing of the alcohol carbon chain length. The concentrations of MES nano-emulsion and compound surfactants were optimized based on the surface/interfacial tension, then the formula of microemulsion-style cleanup additive SFC is obtained: the mass ratio of MES middle phase microemulsion, FS-1 and OP-10 is 140: 3: 9, the additive reaches to the critical micelle concentration at the concentration of 0.35% with the surface tension 25.96mN/m and interface tension 0.2mN/m; MES nano-emulsion can hold back capillarity effectively, after the core is disposed with the MES nano-emulsion, the water absorption quantity absolutely reduces; MES nano-emulsion can increase wetting angle and reduce surface tension of viscosity breaking fluid, then the cleanup rate is improved effectively. At the same time the additive SFC can reduce injury rate of water lock of fracturing fluids and scaling due to poor compatibility of fracturing fluids with formation fluid and has no effect on performances of fracturing fluid gel, viscosity of viscosity breaking fluid, surface/interface tension, carrying sand and hanging, which has a...