Experimental study on an eco-friendly gemini foaming agent for enhancing foam drilling applications

Underbalanced foam drilling (UBFD) represents a pivotal technique aimed at enhancing safety and operational efficiency within drilling operations. Despite its recognized benefits, the challenge of maintaining foam stability persists, particularly in conditions characterized by elevated water salinity and alkalinity. This study endeavors to bridge this gap by introducing the eco-friendly Gemini surfactant (GS12) for drilling foams and evaluating its performance under mildly alkaline conditions. Employing a dynamic foam analyzer, diverse foam properties of GS12 foams were systematically assessed, including stability, foamability, and bubble structure. Results elucidate that the optimal surfactant concentration for maximal foam stability stands at 1.5 wt%; however, a threefold concentration increase (from 0.5 to 1.5 wt%) merely yields a 30% improvement, emphasizing the economic viability of a 0.5 wt% concentration for practical UB applications. Additionally, the study demonstrates a correlation between foam stability and water salinity, with seawater exhibiting a twofold reduction in foam half-life compared to deionized water (decreasing from 27 to 13 min), mitigated by the addition of PAC polymer, which increases foam half-life from 13 to 56 min. Moreover, GS12 + PAC foaming systems exhibit surpassing stability compared to a typical commercial blend, boasting a 78% increase in foam half-life (245 min) and a 21% increase in initial foam volume (245 mL), thereby positioning it as a promising candidate for UB drilling applications. The introduction of GS12 for UB drilling and its comprehensive evaluation under mildly alkaline conditions underscore its potential for sustainable foam drilling, advocating for the utilization of environmentally friendly surfactants and green polymers to enhance drilling sustainability and address pressing industry challenges.