Aqueous Surfactant Systems For Oil Recovery

Abstract

A slug containing 2 percent sulfonate, polymer for mobility control, and sodium tripolyphosphate for multivalent ion control - the entire system driven by a polymer solution - recovered 85 percent of the residual oil from a waterflooded Berea core. Because the surfactant adsorption is low, it appears that the process may be economically feasible for tertiary recovery of oil. Introduction In 1927, Uren and Fahmy concluded that an inverse relationship exists between oil-water interfacial tension and the percentage of oil recovered by waterflooding. In that same year a patent was issued to Atkinson that proposed the patent was issued to Atkinson that proposed the use of aqueous solutions of soap or other materials to decrease the "surface tension" between oil and the flooding medium and thereby increase the recovery of oil. During the next 25 years a major part of the reported research on the use of surfactants to recover oil was carried out by a group at Pennsylvania State U. This group recognized that interfacial tension. wetting conditions (contact angle), and surfactant adsorption were important factors. Preston and Calhoun discussed chromatographic transport of surfactants through porous rocks. Ojeda et al., and Paez et al., correlated residual oil saturation in Paez et al., correlated residual oil saturation in cores after a surfactant flood with sigma/Delta p and with a pore geometry parameter (k phi)1/2. These correlations pore geometry parameter (k phi)1/2. These correlations indicated that residual oil saturation could go to zero at values of sigma/Delta p approaching zero. Excluding patent literature, published research results for the last two decades have discussed the screening of surfactants for oil recovery "efficiency", changing wettability to improve oil recovery, adsorption and chromatographic transport of surfactants, and the role of major factors known to affect oil recovery by aqueous surfactant flooding. A comprehensive study directed primarily toward the influence of interfacial tension was reported by Reisberg and Doscher in 1956. Using a system that combined an aqueous alkali with a surfactant, they measured interfacial tensions less than 0.01 dynes/cm. With this same chemical system they recovered 100 percent of the oil from sand packs and more than 90 percent from Torpedo sandstone cores. Wagner and Leach showed that oil recovery increases when interfacial tension is reduced to about 0.07 dynes/cm and that further small decreases in interfacial tension result in large increases in oil recovery. In 1968, Taber presented theoretical and experimental results that presented theoretical and experimental results that further clarify the relation between residual oil saturation and Delta p/L sigma. He recognized that this correlation group should include the contact angle, but because of difficulties in systematically varying or indeed in even measuring the contact angle inside rocks, he examined the effects of the other parameters only. For Berea cores Taber found that a significant quantity of discontinuous oil (residual) was displaced when the ratio of Delta p/L sigma reached a value of about 5 (psi/ft)/(dynes/cm). He designated this as the critical value of the ratio and noted that further increases in the value of this ratio invariably produce more residual oil. He concluded that nearly 100 percent of the residual oil can be displaced if very high values of Delta p/L sigma, can be obtained. Gogarty and Tosch have recently discussed the principles of micellar surfactant systems. principles of micellar surfactant systems. JPT P. 186

Review of surfactant-assisted chemical enhanced oil recovery for carbonate reservoirs: challenges and future perspectives

“…Designing and optimizing suitable surfactant flood for effective cEOR has always been very challenging and forever evolving. It is one of the robust and high-performance cEOR methods, which has been widely studied in the past decades because of its ability to alter wettability of carbonate reservoirs from the oil/mixed-wet to the waterwet surfaces, lower interfacial tension (IFT) and produce the oil entrapped in these formations (Hill et al 1973;Yang and Wadleigh 2000;Webb et al 2005;Farajzadeh et al 2010;Barnes et al 2012;Ahmadi and Shadizadeh 2013a). The idea of adding surfactants to injected water for reducing oil/water IFT and/or alter wettability thereby increasing oil recovery from reservoirs dates back to the early 1900s (Uren and Fahmy 1927).…”

Synthesis of didodecylmethyl hydroxyl sulfobetaine and its evaluation for alkali-free flooding

“…The chemical method of enhanced oil recovery using surfactants has been studied for many years (Johnson 1957;Scott et al 1965;Hill and Reisberg 1973). Surfactant often used together with alkali, or alkali and polymer in oil recovery (Deborah and Philip 1990;Ball and Surkalo 1990;Kang et al 2000;Samanta et al 2010).…”

Modeling of surfactant and surfactant–polymer flooding for enhanced oil recovery using STARS (CMG) software

“…The surfactant is dissolved in either water or oil to form microemulsion which in turn forms an oil bank (Bera et al 2011). The formation of oil bank and subsequent maintenance of sweep efficiency and pressure gradient by injection of polymer and chase water increase the oil recovery significantly (Hill et al 1973). The idea of injecting surfactant solution to improve imbibitions recovery was proposed for fractured reservoirs (Michels et al 1996) and carbonaceous oil fields in the United States (Flumerfelt et al 1993).…”