Decarbonization Through Reducing Energy Losses in Water Injection Systems: Mechanical Degradation of Drag Reducers in Friction Loops Testing

Abstract

Abstract Drag reducing agents (DRAs) are used to reduce friction created by turbulence flow in water transport and injection systems. The objective of this paper to assess mechanical degradation of rigid and flexible polymers used drag reduction applications. Commercial synthetic polyacrylamide-based DRA and CMHPG polymers were obtained. Synthetic brine was prepared to simulate typical water in surface pipelines. Friction loop test was used to assess friction reduction at various conditions, testing modes, and DRA polymer concentrations. Mechanical degradation of flexible and rigid polymers for drag reduction application was assessed. TGA analysis indicated the activity of the polyacrylamide polymer was 29 wt%. Viscosity measurements indicated ammonium persulfate reduced the viscosity of 1000 ppm polyacralamide-based DRA by 41 and 36% at 25 and 40°C, respectively. Flow loop testing showed that the flexible polymer was mechanically degraded (i.e. DR’ < 0.1) within 15, 47, and >200 min at 12 gal/min, NRe 70,022, 75°F, at reservoir tank bypass flow mode using 150, 300, and 1000 ppm of the PAM-based DRA, respectively. Rigid polysaccharides-based drag reducing agents showed significant resistance to mechanical degradation compared to polyacralamide-based DRA. Mechanical degradation of the polymer (via chain scission) was mainly caused by shearing/turbulence flow, circulation pump, number of flow cycles, and time. The degradation rate depended on DRA concentration, flow rate, polymer type, and circulation flow mode. DRA injection is a viable alternative to increase production capacity and/or improve energy efficiency.