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PETROMAKS2-Stort program petroleum

Optimizing CO2 Foam EOR Mobility Control for Field Pilots

Alternative title: CO2 skum for mobilitetskontroll i EOR med CO2 lagring

Awarded: NOK 6.7 mill.

Project Manager:

Project Number:

301201

Application Type:

Project Period:

2020 - 2024

Partner countries:

Global energy strategies must reflect climate and societal challenges. Technologies must be developed to reduce emissions and improve energy efficiency. Carbon capture, utilization, and storage (CCUS) is a readily available technology for substantial emission cuts for many industries. CCUS can involve capturing CO2 emissions from industrial sources and utilizing the CO2 for simultaneous energy production and CO2 storage in subsurface reservoirs. The aim is to reduce the life-cycle emissions of fossil fuels and provide an economic pathway to decarbonizing our energy system. A major part of CCUS is CO2 enhanced oil recovery (EOR) and CO2 storage. CO2 EOR can store the gigaton volumes of CO2 needed to mitigate climate change, while generating revenue for the industry; a crucial criteria for wide-spread implementation of CCUS. However, a major problem during CO2 injection is the low density and viscosity of CO2 at reservoir conditions. These adverse properties can restrict energy production and CO2 storage efficiency. Foaming CO2 is an effective method to mitigate unfavorable CO2 properties for improved energy production and increased CO2 storage potential. CO2 foam injection involves injecting a foaming agent with CO2 to reduce its mobility and improve displacement efficiency. Previous foam field tests have been reported as technical successes with evidence of foam generation, improved sweep efficiency, and enhanced oil recovery. Others were deemed unsuccessful due to injectivity problems and limited foam propagation in the reservoir. Thus, a more thorough understanding of foam dynamics, strength, stability, and size-dependent displacement mechanisms is needed to advance the technology. This project aimed to gain a more thorough understanding of foam systems at reservoir conditions to optimize CO2 foam mobility control technology for field pilot testing. The project was a multi-scale study, spanning from pore- to field-scale, which utilized state-of-the-art methods and tools, including high pressure/high temperature pore- and core-scale experiments, advanced in-situ imaging with PET/CT, and numerical modeling. The project employed one PhD student and one Researcher who have combined to publish 7 scientific papers. In addition, 12 co-scientific talks have been delivered at international conferences and one PhD student graduated from the project. The project results improve the understanding of foam flow physics which is essential to increase the accuracy of field-scale foam modeling. Project results also determined the effect of various factors on foam generation and stability, including the presence of oil, rock permeability, and the presence of nanoparticles. In addition, the results demonstrated the benefits of using CO2 foam for EOR and CO2 storage compared to other CO2 injection methods. Utilization of state-of-the-art experimental methods that deployed field-scale injection strategies, combined with advanced in-situ PET/CT imaging, made an important contribution to the fields of reservoir physics, fluid flow in porous media, in-situ imaging, and CCUS. Overall, this project provided important knowledge for optimizing future field-scale COP2 EOR and CO2 storage applications to reduce emissions while providing low-carbon energy for a transition to a net-zero society.

Foam is shown in this project to significantly increase CO2 storage and CO2 EOR performance. Utilizing CO2 for EOR provides a mutually beneficial scenario to reduce GHG emissions and provide energy security. In addition, CO2 EOR is a critical component to encourage CO2 storage efforts within carbon capture, utilization, and storage (CCUS), which is the most feasible technology available to store the vast amounts of CO2 needed to mitigate climate change. This project has demonstrated that CO2 foam EOR enables CCUS, providing a revenue for the industry when storing CO2 as CCUS. This project has established a lower threshold for implementing CO2 EOR in areas where CO2 storage has already been realized (on the NCS). Further, this project provides innovative insight into nanoparticle-stabilized CO2 foam behavior and improves the understanding of scale-dependent displacement mechanisms, while establishing more accurate multiscale modeling. More efficient workflows is therefore offered for field implementation of nanoparticle-stabilized foams, for CO2 mobility control and for EOR and associated CO2 storage. Quantitative results: - Oil production by CO2 foam injection exhibits 40% additional oil compared to predicted baseline conventional CO2 EOR - Chemical and CO2 costs are reduced by 20% at 70% foam quality - Operational time is reduced by 70-80% compared to conventional CO2 EOR - CO2 sweep efficiency increased 40% in EOR - CO2 storage increased to 40% in CCUS and 60% in CCS - Rate of Return for implementation of CO2 Foam EOR as CCUS is at a factor of 20

Norway has more than 23 mature waterflooded reservoirs with ca. 2 400 million Sm3 residual oil as an EOR target. In gas EOR, the low density and viscosity of injected gas results in viscous fingering, gravity override, and flow in thief zones causing poor reservoir sweep efficiency and low oil recoveries. Foam for mobility control can improve gas EOR performance by mitigating gas injection challenges. Foam injection involves injecting a soap (surfactant solution) with gas, such as carbon dioxide (CO2), where simultaneous CO2 storage assists in reducing GHG emissions. Using nanoparticles in conjunction with surfactants can increase the stability of mobility control foams. However, there is a knowledge need to improve the understanding of size-dependent NP CO2 foam dynamics. Thus, this project proposes to develop new knowledge and upscaling strategies by performing pore- and core-scale experiments and numerical modeling to understand NP CO2 foams at reservoir conditions. A key innovation of this project is the use of combined positron emission tomography (PET) and computed tomography (CT) to visualize in-situ fluid saturations and characterize NP CO2 foam systems in the laboratory for qualitative and quantitative analysis of foam’s impacts on CO2 mobility, fluid displacement, and nanoparticle retention and concentration. Advanced laboratory techniques coupled with multiscale modeling provides an improved methodology to further the current understanding of foam dynamics at multiple scales, while establishing better tools for predictive modeling of NP CO2 foam processes. The project will utilize expertise developed in two ongoing NFR/CLIMIT projects (249742 and 268216), which include onshore CO2 foam field pilots and investigation of NP foam at harsh reservoir conditions. The overarching goal is to optimize CO2 foam systems to prepare for an onshore field pilot in collaboration with upcoming funding calls from USDOE and NFR.

Funding scheme:

PETROMAKS2-Stort program petroleum