Experimental study on the use of surfactant as a fracking fluid additive for improving shale gas productivity

A substantial quantity (60-80%) of water utilized through hydraulic fracturing in shale formations stays trapped within the formation primarily because of capillary forces. The retained water could obstruct the flow path of gas therefore trapping it and decreasing its productivity. Surfactants are utilized as additives to lower the surface tension between gas and water, which includes a reduction in the capillary pressure and therefore easier flow of gas to be produced as well as water to be retrieved. Within this paper, the effects of BIO-TERGE (R) AS-40 surfactant on improving the performance of the fracturing fluid had been researched in the existence and lack of additional chemical additives at several fracking water salinities. The efficiency of the included surfactants was analyzed by measuring the surface tension between methane gas and surfactant mixtures utilizing the pendant drop technique at various temperatures and pressures. As results, BIO-TERGE (R) AS-40 has lowered the surface tension between methane gas and water from about 69 mN/m to 32.49 mN/m at critical micelle concentration (CMC) of 0.75 wt% and 10,000 ppm salinity. The addition of the nonionic Betain C60 has decreased the surface tension to a low value of 30.79 mN/m. The surfactant had a significant effect on reducing the contact angle, causing the shale rock to become more water wet. Reduction of surface tension as well as the change in the wetting phase aids in enhancing the desorption of gas from the shale. Furthermore, it was obvious that increasing the temperature and pressure would likely reduce the surface tension. The obtained information from this study can be utilized to optimize the performance of fracture fluid and then improve the shale gas production and overall sweep efficiency in addition to water flowback.