Study And Application Of Clean Fracturing Fluids

Based on studying the relationship between concentration and viscosity of common surfactants, Long chain alkyl quaternary ammonium salts cationic surfactant was screened and determined to be used as the clean-fracturing fluids. On the basis of the structure, two Gemini quarternary ammonium surfactants were synthesized, and the molecular structure of products was characterized by IR and 1HNMR.The rheological property and viscoelasticity were investigated, and the results indicated that this kind of structure was proved to be excellent as fracturing fluid. This study selected the best fracturing fluid formula of Gimini surfactants / NaSal system, and the capacity of heat and shear resistant, breaking down, suspending proppant, and filtration were evaluated. In addition, the effect of inorganic salts, small organic molecules, as well as the pH value on the system was also investigated.The clean-fracturing fluids were applied to 12 wells in peripheral fuyang oil layer and Daqing placanticline successfully, and the success rate was above 80 % in fracturing.