Study on Controllable Slick Water Based on Stimulus Response Strategy

In some areas with complicated geological conditions, low porosity, low permeability and low formation pressures, tough problems such as gas reservoirs developed with micron and nanometer sized pores, narrow pore throats, high displacement pressures and poor connectivity etc. are often encountered, which inevitably result in serious damage to water block ability and more difficulties in flowing back fracturing fluids. To solve these problems, stimulus response surfactants were introduced into the water solution of hydrophobic associating polymers to render slick water controllable viscosity. The friction of the slick water formulated can be reduced by 78.1%. The difficulties of flowing back the slick water were greatly mitigated through regulation and control, and formation damage was further reduced. Dynamic light scattering experiment was used to prove that the molecules of the surfactants can be assembled into different structures at different pH values. The hydrophobic associating polymers can interact with these structures to realize the viscosity control of the slick water. The slick water system formulated has good friction reducing property and swelling inhibition ability.