Optimizing the Value of a CO2 Water-Alternating-Gas Injection Project under Geological and Economic Uncertainties

Precious Ogbeiwi, Karl D. Stephen

Research output: Contribution to journalArticlepeer-review


Summary The numerical simulations required for the robust optimization (RO) of the alternating injection of water and CO2 in hydrocarbon reservoirs are computationally expensive due to engineering, geological, and economic uncertainties. Using approximation models of the desired objective function(s) can significantly decrease the cost associated with the optimization routines while providing an adequate sampling of the input variables or uncertainties. In this study, we optimized the value of a water-alternating-gas (WAG) injection project in a Niger-Delta oil reservoir by applying the Markowitz classical theory to a suitable approximation model of the objective function. Our RO methodology incorporated significant geological and economic uncertainties—such as uncertainties due to the upscaling of the coarse-scale reservoir model and those due to the lack of other relevant geological and economic data—to the optimization routine to create better operating strategies for the projects that are risk-quantified. To compute the objective function, a novel economic model for the CO2 sequestration processes in the Niger-Delta hydrocarbon basin was applied. The result obtained in the presented case showed that a net present value (NPV) of at least USD 65.98 million was derived from the project depending on the engineer’s or user’s confidence level. Overall, the applicability of proxy models to RO routines was demonstrated. As a result, investment decisions that accounted for uncertainties and any potential variation in the field’s operation and development were made.
Original languageEnglish
Pages (from-to)1-21
Number of pages21
JournalSPE Journal
Early online date22 Feb 2024
Publication statusE-pub ahead of print - 22 Feb 2024


  • Geotechnical Engineering and Engineering Geology
  • Energy Engineering and Power Technology


Dive into the research topics of 'Optimizing the Value of a CO2 Water-Alternating-Gas Injection Project under Geological and Economic Uncertainties'. Together they form a unique fingerprint.

Cite this