A Novel Low-Damage Viscoelastic-Surfactant Foam Fracturing Fluid for Tight Reservoirs: Development and Performance Assessment

Abstract

As oil and gas development increasingly targets unconventional reservoirs, the limitations of conventional hydraulic fracturing, namely high water consumption and significant reservoir damage, have become more pronounced. This has driven growing interest in the development of clean fracturing fluids that minimize both water usage and formation impairment. In this study, a low-liquid-content viscoelastic surfactant (VES) foam fracturing fluid system was formulated and evaluated through laboratory experiments. The optimized formulation comprises 0.2% foaming agent CTAB (cetyltrimethylammonium bromide) and 2% foam stabilizer EAPB (erucamidopropyl betaine). Laboratory tests demonstrated that the VES foam system achieved a composite foam value of 56,700 mL·s, reflecting excellent foaming performance. Proppant transport experiments revealed minimal variation in suspended sand volume over 120 min across different sand ratios, indicating robust sand-carrying capacity even at high proppant concentrations. Rheological measurements showed that the fluid maintained a viscosity above 120 mPa·s after 120 min of shearing at 70°C and a shear rate of 170 s−1, with the elastic modulus exceeding the viscous modulus, confirming the system’s exceptional stability and resilience. Furthermore, core damage tests indicated that the VES foam caused only 4.42% formation damage, highlighting its potential for efficient and low-damage stimulation of tight reservoirs. Overall, the findings demonstrate that this low-liquid-content VES foam provides a highly effective, environmentally considerate alternative for hydraulic fracturing in unconventional formations, combining superior proppant transport, rheological stability, and minimal reservoir impairment.