Complex Phased Development for CO2 EOR in Oil Carbonate Reservoir, Abu Dhabi Onshore

Abstract

CO2 injection into oil reservoirs for EOR is well known as one of the most proven and efficient Enhanced Oil Recovery (EOR) processes. The subject study was conducted with the objective of enhancing oil recovery by injecting CO2 into a heterogeneous, low dipping and low permeability carbonate oil reservoir. The required CO2 is captured from a steel plant (Emirates Steel Industry (ESI)) which is part of a large scale carbon capture and injection project. The project entails capturing, dehydrating, compressing, and transporting the CO2 to the oilfields for sequestration and/or EOR processes. The carbon capture from ESI is part of a collaboration (Joint Venture) between ADNOC and MASDAR which will help make CO2 available for potential future EOR operations along with the added benefit of reducing Abu Dhabi's carbon footprint. As part of this initiative, planning of the CO2 EOR process as part of ADNOC's EOR strategy is essential and includes building a phased development CO2 EOR model. The strategy is to breakdown the overall objective into phased developments/projects in order to gain experience in surface and subsurface aspects of CO2 EOR, operations and mitigate risk. The end goal of the phased development is to enhance oil recovery, improve CO2 utilization, and maximize project profitability by implementing more complex operations such as Continuous/WAG CO2 injection, CO2 recycling, and the development of "difficult oil" from flank areas with higher water saturation (transition zone). This paper discusses the benefits and rationale behind building such a phased development model.

A review of CO2 storage in geological formations emphasizing modeling, monitoring and capacity estimation approaches

“…Mathieson et al 2010, Onuma and Ohkawa (2009) and Ringrose et al (2009) Rumaitha Zone-B, Abu Dhabi EOR Cross-well seismic; DTS (distributed temperature sensing in observation well, 41 meters from injector; permanent multi-phase flow meter (MPFM), logging tools, sponge coring near injector well; production data analysis Al-Hajeri et al (2010) and Figuera et al (2014Figuera et al ( , 2016 be developed in the cap rock if the temperature of the injected CO 2 is much lower than the in situ temperature in the aquifer. In the Abu Dhabi Rumaitha Zone-B project, the CO 2 is heated at the surface prior to injection, to ensure thermal induced fractures are not created in the reservoir.…”

Robust NMR Examination of the Three-Phase Flow Dynamics of Carbon Geosequestration Combined with Enhanced Oil Recovery in Carbonate Formations

“…In this respect, net-zero emissions can be attained economically by carbon geosequestration and enhanced oil recovery (CGS-EOR) in saline aquifers and depleted hydrocarbon reservoirs. Such CO 2 -EOR projects are carried out both to reduce global warming caused by human CO 2 emissions and to fulfill the increasing need for energy worldwide. − The use of subsurface CO 2 injection in environmental and petroleum engineering is therefore crucial. , However, EOR and residual CO 2 trapping are greatly impacted by the oil layers, pore sizes, and fluid displacement. − For instance, when production occurs below the oil’s bubble point pressure, CO 2 injection can lead to a three-phase (brine/oil/CO 2 ) flow, wherein the single wetting phase (brine) and nonwetting phase (e.g., CO 2 ) of the typical two-phase flow system are accompanied by an additional, intermediate-wetting phase. − Here, it should be noted that brine is already present in the reservoir prior to the migration of hydrocarbons; however, secondary recovery often involves flooding with additional brine . As a result, the three-phase flow system is considerably more complex than the analogous two-phase flow system. , Consequently, three-phase flow studies are expensive and time-consuming to run, and it can be challenging to comprehend how the brine–oil–CO 2 mixture flows through a porous rock, especially under reservoir conditions .…”

Residual Co2 Trapping and Enhanced Oil Recovery in Carbonate Reservoirs: Three-Phase Flow Dynamics Examined Via Nmr

“…Injecting CO 2 into subsurface reservoirs (e.g. depleted hydrocarbon reservoirs) is a promising strategy for CO 2 capture and storage (CCS), especially when combined with simultaneous enhanced oil recovery (EOR) [1][2][3][4][5]. Such CO 2 -EOR projects are implemented to mitigate global warming (caused by CO 2 emissions from anthropogenic sources) and meet ever-growing global energy demand [6][7][8].…”