Development and Evaluation of Foam-Based Conformance Control for a High Salinity and High Temperature Carbonate

Abstract

Carbonate reservoirs’ extreme heterogeneity in the form of fracture corridors and super-permeability thief zones present challenges to the efficient sweep of oil in both secondary and tertiary recovery operations. In such reservoirs, conformance control is crucial to ensure injected water and any EOR chemicals optimally contact the remaining oil with minimal throughput. Foam-based conformance control is a relatively new technology especially its use for in-depth diversion in high salinity high temperature conditions. In this work, a laboratory study was conducted to develop and evaluate a foam-based conformance control technology for application in a high salinity and high temperature carbonate. Foaming agents were first screened for their suitability with regard to reservoir temperature and salinity where properties such as foamability and foam stability were measured. The best performing surfactants were then used to study the mobility reduction across a core composite at reservoir temperature and pressure. Foam stability and decay were also investigated in those permeability reduction experiments. Brine and crude oil were injected after foam formation and pressure drops and sustainability of mobility reduction were quantified. The improvement in reservoir contact and hence oil recovery were examined by oil displacement experiments conducted in specially prepared heterogeneous composites. For the studied conditions of high salinity and high temperature, foaming agents of the amphoteric family as well as a special blend were found suitable in terms of salt tolerance and foam stability. The mobility reduction due to foam was 12 times without oil and 6 times in the presence of oil. Oil recovery improvement with foam application was also found to be significant. These results demonstrate the potential of the identified foam system and its favorable impact on sweep efficiency despite the harsh salinity and temperature conditions of the studied carbonate reservoir.

Experimental Study of Profile Control with Foam Stabilized by Clay Particle and Surfactant

“…This trend coincides with conclusions in the literature [29]. Compared with previous works under the same gas-liquid ratio, the resistance factor of clay-HY-2 foam in this study is five to ten times higher than those of traditional foams [30,31]. However, the difference among resistance factors of various parts is large in Figure 13a, and the extra high resistance factor at the front part of the sandpack means that most bubbles and clay particles assemble at the entrance of the sandpack.…”

“…As for flooding experiments in sandpacks, the effect of different factors such as the gas-liquid ratio, temperature, and permeability on profile control were investigated. The clay-HY-2 foam performs the efficient and uniform profile control effect on sandpacks when the foam quality is around 50% [29][30][31][32][33]. The resistance factors of the foam decrease gradually with the increasing temperature, however, the resistance factor remains higher than 350.0 when the temperature reaches 80.0 • C. When the permeability exceeds 1502.0 mD, the clay-HY-2 foam can perform deep profile control in reservoirs, and the resistance factors are not sensitive to the change of permeability when it exceeds 3038.0 mD.…”

A comprehensive review of the chemical-based conformance control methods in oil reservoirs

“…There has been a successful application of foam in completion operations where the foam redirects acid to less permeable zones thereby improving the result of acid stimulation. Foam has been applied for near-wellbore treatments and to abate gas coning in gas cap reservoirs (Fuseni et al 2018). Foam consists of a gas/gas-like phase which is dispersed in a continuous liquid phase (surfactant).…”

Polyvinylpyrrolidone-resorcinol-formaldehyde hydrogel system reinforced with bio-synthesized zinc-oxide for water shut-off in heterogeneous reservoir: An experimental investigation

“…To overcome the issue of excessive water production due to the presence of reservoir heterogeneity, various chemical methods e.g., polymer, in-situ gel systems, particle gel systems, foams, etc. have been widely used in the oilfield globally (Al-Anazi and Sharma, 2002;Al-Muntasheri et al, 2007;Fuseni et al, 2018;Goudarzi et al, 2014;Wassmuth et al, 2004;Zhao et al, 2014). Among them, crosslinked in-situ polymer gel systems have been a cost-effective method and are usually applied for enhancing oil recovery by controlling excessive water production in mature oil fields (Moradi-Araghi, 2000;Zhu et al, 2017).…”