Corrosion inhibitor and chelating agent impact on foam stability for formation stimulation applications

Injection of foam into petroleum reservoirs has attracted special interest in the last years. Utilizing foam in well stimulation is promising as it consumes less water than water-based fracturing fluids. Nevertheless, the success of foam application mainly depends on its stability. Thus, it is essential to understand the role of gas type, water chemistry, and other additives such as acids (e.g., chelating agent) and corrosion inhibitors on the generation and stabilization of foam. Hence, a dynamic foam analyzer (DFA) and optical interfacial tensiometer were used to study foam stability under different conditions. Surfactant screening showed that Duomeen TTM and Armovis are superior foamers at low pH (3.5), and therefore were used in this study. The liquid phase typically contained high salinity water, 15 %wt. Chelating agent, L-glutamic acid-N, N-diacetic acid (GLDA), and 1 %wt. surfactant with and without a corrosion inhibitor (CI). First, we investigated the effect of gas types on the stability of the foam. The results revealed that N2-foam is more stable compared to CO2-foam. Also, the results showed that the corrosion inhibitor reduced the foam stability for both N2-foam and CO2-foam. Three types of water were examined; distilled water (DI), produced water (PW), and seawater (SW) for foam stabilization. The water chemistry had little effect on the stability of TTM compared to its impact on Armovis. Finally, we found that GLDA addition to Armovis increased the stability of foam by four times compared to no GLDA addition. Moreover, the stability GLDA/Armovis system was six times higher with CO2 and more than 20 times higher with N2 as compared to TTM stability. The foamability, foam volume, bubble count, and foam structure were studied to determine the foam behavior at given conditions. This study provides a broad understanding of additives' impact on stimulating foam stability.