As the discovery rate of new hydrocarbon resources decreases, the need for more-efficient enhanced-oil-recovery processes increases. Unlike in the past, however, when the efficiency was defined in terms of maximizing the recovery factor (RF), the new interpretation of efficiency is based on optimizing the balance between RF and the reduction of carbon footprint.
As the discovery rate of new hydrocarbon resources decreases, the need for more-efficient enhanced-oil-recovery (EOR) processes increases. Unlike in the past, however, when the efficiency was defined in terms of maximizing the recovery factor (RF), the new interpretation of efficiency is based on optimizing the balance between RF and the reduction of carbon footprint. This is done through an integrated approach in which both surface and subsurface elements of the oil-production systems are used to determine energy efficiency and carbon footprint of a unit volume of oil produced by EOR methods.
When choosing traditional EOR methods, new innovations may be needed to arrive at new injectant composition to reduce emissions or make the process more efficient. Adding chemicals to the injectant gas to improve the mobility ratio and increase the sweep efficiency is desirable. One example is the use of hydrogels. These are hydrophilic structures that swell when hydrated. Hydrogels are of interest in EOR because of their ability to respond to stimuli such as pH, temperature, light, and ionic strength.
EOR methods that involve use of fresh water are also switching to alternative methods that reduce or remove its usage as part of water sustainability. The produced water could be treated properly to make it suitable for injection. Alternatively, polymers that are effective under high salinity or temperature could be used to deal with injecting saline water. For unconventional reservoirs, waterless fracturing techniques are progressing.
Paper SPE 201609 discusses the application of a reversible hydrogel that can be added to the injected carbon dioxide (CO2) stream in order to make it a more-efficient injectant for EOR and, hence, create more opportunity for CO2 storage. Paper SPE 202809 deals with utility of new polymers that are suitable for injection into carbonate reservoirs under high-temperature and ultrahigh-salinity conditions. Finally, paper OTC 30437 discusses ways of mitigating safety risks associated with CO2 waterless fracturing in unconventional reservoirs as part of water sustainability as well as prevention of environmental pollution.
This Month’s Technical Papers
Recommended Additional Reading
SPE 200357 Fundamental Investigation of Auto-Emulsification of Water in Crude Oil: An Interfacial Phenomenon and Its Pertinence for Low-Salinity EOR by Duboué Jennifer, TotalEnergies, et al.
SPE 205118 Experimental Design and Evaluation of Surfactant Polymer for a Heavy-Oil Field in South of Sultanate of Oman by Ali Reham Al-Jabri, Petroleum Development of Oman, et al.
SPE 200256 Chemical Enhanced Oil Recovery and the Dilemma of More and Cleaner Energy by Rouhi Farajzadeh, Delft University of Technology, et al.
Reza Fassihi, SPE, is a distinguished adviser emeritus with BHP. His primary responsibilities include technical assurance, competency development within the company, identification and development of emerging technology, and provision of technological advice to senior management. Fassihi was a technical liaison for joint-industry projects on carbon dioxide sequestration, alternative energy including geothermal, and innovative technologies for mineral extraction. He has more than 40 years of experience in petroleum research, development, and management of both conventional and unconventional reservoirs. Before joining BHP Billiton, Fassihi worked with Arco, Amoco, and BP. As a founder of Beyond Carbon, LLC, he provides consulting services with a focus on how to reduce the carbon footprint in the energy industry.
He has served as a member of several SPE committees, including the 2022 IOR Technical Program Committee, the steering committee for SPE Forums, and the SPE Reservoir Description and Dynamics Advisory Committee. Fassihi was an SPE Distinguished Lecturer in 2003. He is an executive editor for the SPE Journal Editorial Board and was named an SPE Distinguished Member in 2018. Fassihi has published more than 45 peer-reviewed papers and is the author of the SPE monograph Low-Energy Processes for Unconventional Oil Recovery and is a member of the JPT Editorial Review Committee.