An Integrated Carbon-Dioxide-Foam Enhanced-Oil-Recovery Pilot Program With Combined Carbon Capture, Utilization, and Storage in an Onshore Texas Heterogeneous Carbonate Field

Abstract

Summary A carbon–dioxide (CO2) –foam enhanced–oil–recovery (EOR) field pilot research program has been started to advance the technology of CO2 foam for mobility control in a heterogeneous carbonate reservoir. Increased oil recovery with associated anthropogenic–CO2 storage is a promising technology for mitigating global warming as part of carbon capture, utilization, and storage (CCUS). Previous field tests with CO2 foam report various results because of injectivity problems and the difficulty of attributing fluid displacement specifically to CO2 foam. Thus, a comprehensive integrated multiscale methodology is required for project design to better link laboratory– and field–scale displacement mechanisms. This study presents an integrated upscaling approach for designing a miscible CO2–foam field trial, including pilot–well–selection criteria and laboratory corefloods combined with reservoir–scale simulation to offer recommendations for the injection of alternating slugs of surfactant solution and CO2, or surfactant–alternating–gas (SAG) injection, while assessing CO2–storage potential. Laboratory investigations include dynamic aging, foam–stability scans, CO2–foam EOR corefloods with associated CO2 storage, and unsteady–state CO2/water endpoint relative permeability measurements. Tertiary CO2–foam EOR corefloods at oil–wet conditions result in a total recovery factor of 80% of original oil in place (OOIP), with an incremental recovery of 30% of OOIP by CO2 foam after waterflooding. Stable CO2 foam, using aqueous surfactants with a gas fraction of 0.70, provided mobility–reduction factors (MRFs) up to 340 compared with pure–CO2 injection at reservoir conditions. Oil recovery, gas–mobility reduction, producing–gas/oil ratio (GOR), and CO2 utilization at field pilot scale were investigated with a validated numerical model. Simulation studies show the effectiveness of foam to reduce gas mobility, improve CO2 utilization, and decrease GOR.

Core-scale sensitivity study of CO2 foam injection strategies for mobility control, enhanced oil recovery, and CO2 storage

“…The core-scale simulation model utilized the foam stability measurements in Figure 2 to fit the empirical local equilibrium foam model by curve fitting regression [23,30]. The value for the maximum gas mobility reduction, fmmob, however, was reduced to 41.5 in agreement with previous findings on field core material to reflect more realistic conditions for the field system.…”

“…A compositional simulation case was generated which contained 14 oil components and 2 water components (water and surfactant). Relative permeability curves were derived from CO2/brine displacement experiments on similar core material described elsewhere [23]. Despite their influence on foam behavior, capillary pressure effects were not included in this study.…”

“…A maximum gas mobility reduction (fmmob) is also used to set the maximum mobility reduction that can be achieved by foam. These parameters were derived from foam quality and rate scans and fit to the empirical model by curve fitting regression [23,30].…”

“…Miscible CO2 foam injection will be implemented to reduce high producing gas-oil-ratios, CO2 recycling, and to provide mobility control for increased CO2 sweep efficiency. The reservoir pressure in the pilot area is 220 bars, which is close to the formation fracture pressure of 269 bars [23]. An injection strategy must be selected that will not fracture the formation, which would cause problems beyond any remediation by the foam.…”

“…A secondary objective is to investigate the impacts of miscibility conditions on in-situ foam generation and stability. For more detailed information on the field pilot program see Alcorn et al (2019).…”