Effect of anionic surfactant on the properties of nonionic hydrophobically associating polymer based slick water

Abstract

A water-soluble nonionic surfactant hydrophobic monomer (AT100) was synthesized by esterification of acryloyl chloride with Triton X-100, after that, a nonionic hydrophobically associating polyacrylamide P(AM-AT100) was synthesized and used as drag reducer. They were characterized by IR and NMR. In fresh water, when the concentration of drag reducer reached 0.3 g·L⁻¹ (so called slick water), the viscosity was 3.86 mm²·s⁻¹ with a drag reduction rate up to 74.7%. After sodium dodecyl sulfate (SDS) was added into the slick water, hydrophobic chains of SDS and hydrophobic units in P(AM-AT100) aggregated and micelles were likely formed, and this process was just like hydrophobic association. The viscosity of the slick water increased significantly, while the drag reduction rate of the mixed system decreased. With SDS concentration at 1.5 g·L⁻¹ and the drag reducer concentration at 0.3 g·L⁻¹, the drag reduction rate was 71.72% and viscosity was 6.25 mm²·s⁻¹, indicating that increasing viscosity had a significantly adverse effect on drag reduction performance. The proppant layup experiment confirmed that the sand-carrying capacity of low-viscosity slick water is limited, so proppant will settle inevitably.

Graphical Abstract

Keywords:

• Shale gas
• slick-water
• hydrophobically associating polyacrylamide
• drag reduction rate