Abstract
Enhanced oil recovery methods are the future of maximizing oil recoveries. Any incremental oil recovery can support the world economy by producing more oil at a minimum price. The surfactants are the major constituent of the injection fluids for EOR applications. Addition of foam-generated surfactants in water alternating gas injection is one of the potential solutions for reducing the gas mobility and improving sweep efficiency, but the major challenge of surfactants used with water alternating gas injection is its stability in presence of formation water and crude oil at reservoir conditions. The objective of this study is to investigate the stable surfactant as a foaming agent to improve the efficiency of residual oil and reduce the gas mobility. To achieve this main objective, individual and new surfactant blended formulations were evaluated with injection water and crude oil in the porous media at 96 °C and 1400 psi. Experimental result showed that generated foam in presence of crude oil has reduced gas mobility which provides good indication of CO2 mobility control and improves sweep efficiency. Oil recovery based on original oil-in-place by surfactant blend of 0.6 wt% AOS + 0.6 wt% TX 100, 0.6 wt% AOS + 0.6 wt% LMDO and individual surfactant of 0.6 wt% AOS were recorded as 91.9, 83.7 and 72.66%, respectively. Foam stability in presence of crude oil, reduction in gas mobility and increase in oil recovery indicated that these surfactant blends are good foaming agents as compared to individual surfactant in enhanced oil recovery applications.
Highlights
The first reported water alternating gas (WAG) field pilot was implemented in the North Pembina field, Alberta, Canada in 1956–1957 (Algharaib et al 2007; Nadeson 2004)
Addition of foam-generated surfactants in water alternating gas injection is one of the potential solutions for reducing the gas mobility and improving sweep efficiency, but the major challenge of surfactants used with water alternating gas injection is its stability in presence of formation water and crude oil at reservoir conditions
The objective of this study is to investigate the stable surfactant as a foaming agent to improve the efficiency of residual oil and reduce the gas mobility
Summary
The first reported water alternating gas (WAG) field pilot was implemented in the North Pembina field, Alberta, Canada in 1956–1957 (Algharaib et al 2007; Nadeson 2004). Foam surfactants are used in near wellbore flow treatments such as foam–acid matrix stimulation and plugging of unwanted phases (Chang et al 2002; Wassmuth et al 2004), in fractured fluids (Blauer and Kohlhaas 1974; Wheeler 2010), in shallow subsurface environmental remediation (Hirasaki et al 1997; Mamun et al 2002; Hirasaki 1989) and in EOR processes to control the gas mobility and overcome in situ permeability variations (Blaker et al 2002) This method can be applied by simultaneously injecting gas and surfactant solution or alternating gas with brine-added surfactant solution (Dholkawala et al 2007). Apparent molecular weight Density of CO2 (Ib/ft3) Viscosity of CO2 (cp) Critical temperature (°C) Critical pressure (Psi)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
