Screening Criteria and Considerations of Offshore Enhanced Oil Recovery

Abstract

Abstract:The application of enhanced oil recovery (EOR) in offshore oil fields has received significant attention due to the potentially enormous amount of recoverable oil. However, EOR application offshore is in its very early stage due to conditions that are more complex than onshore oil fields, owing to the unique parameters present offshore. Therefore, successful EOR applications in offshore oil fields require different screening criteria than those for conventional onshore applications. A comprehensive database for onshore applications of EOR processes together with a limited offshore EOR application database are analyzed in this paper, and the important parameters for successful offshore application are incorporated into the new EOR screening criteria. In this paper, screening criteria to determine acceptable EOR processes for offshore fields, including hydrocarbon gas miscible, CO 2 miscible, and polymer processes, are presented. Suggested screening criteria for these EOR processes comprise quantitative boundaries and qualitative considerations. Quantitative screening criteria are predominantly based on quantifiable data, such as oil and reservoir properties. Qualitative screening considerations mainly focus on the operational issues present offshore, including platform space constraints, limited disposal options, injectant availability, and flow assurance matters (including hydrate formation and difficulties in emulsion separation).

CO2-EOR/Sequestration: Current Trends and Future Horizons

“…And at some point under the appropriate conditions, the enrichment reaches a level where the injected gas becomes miscible with oil in the reservoir. It is from this stage of the process, under ideal conditions, that displacement is said to occur [20][21][22]. When using a condensing or enriched gas as the injecting fluid, the process is more expensive because the fluid tends to contain a high concentration of intermediatemolecular-weight hydrocarbons.…”

“…Firstly, the separation of CO 2 from the produced gas is the ideal choice if the CO 2 source is not in the vicinity of the field. Next, at high CO 2 concentrations, there is a need for the facilities and operation to process the gas [21]. This is because CO 2 becomes acidic as it is injected into the (formation) water and causes corrosion of the equipment in the offshore environment.…”

“…This is because CO 2 becomes acidic as it is injected into the (formation) water and causes corrosion of the equipment in the offshore environment. If the fields are using CO 2 -WAG processes, then the facilities need to be compatible with acid that could be generated so that the corrosion in the facilities could be prevented [20][21][22].…”

Artificial Neural Network Model to Estimate the Viscosity of Polymer Solutions for Enhanced Oil Recovery

“…To reduce the decline of reservoir pressure and push the oil in the reservoir to the production well, water flooding (secondary recovery), which is the process of injecting water into the reservoir, has been commonly applied to most oil fields. The primary and water flooding methods typically extract no more than 10%-40% of the original-oil-in-place [1]. One of the main reasons for oil to remain after water flooding is the high mobility of the injected water induced by its low viscosity.…”

“…Nomenclature α empirical constant, generally two a 1 -a 7 empirical constants b 1 -b 6 empirical constants C 1 Na + concentration c 1 empirical constant C 2 Ca 2+ concentration C p polymer concentration d 1 Newtonian viscosity at a high shear rate, generally solvent (water) viscosity η 0 Newtonian viscosity at a low shear rate λ empirical constant…”