Enhancing CO₂ huff-n-puff strategies for improved oil recovery in the Bakken formation: A numerical simulation approach

Abstract

This study investigates the performance of various huff and puff (HnP) strategies for enhanced oil recovery (EOR) in the Sanish field of the Bakken formation, using a numerical model developed with CMG software. The model integrates PVT validation, CO₂ miscibility, swelling tests, heterogeneity, and history matching with field data. Several HnP strategies, including Supported (S HnP), Alternative Supported (AS HnP), and Alternative Zigzag Supported (AZS HnP), were evaluated. Key findings show that dual porosity and permeability are essential for accurate modeling, while CO₂ diffusion has minimal impact in field-scale simulations with high fracture spacing. The S HnP strategy improves oil recovery with 50% less CO₂ than the Normal HnP, and the AS HnP further enhances production. The AZS HnP outperforms both, offering higher oil recovery and better CO₂ utilization. Fracture length was found to influence recovery significantly, and the sensitivity of oil production to CO₂ injection rates was notably higher in the AZS HnP compared to the N HnP scenario. These results highlight the potential for optimized CO₂-EOR strategies in unconventional reservoirs.

Keywords

Carbon dioxide enhanced oil recovery (CO₂-EOR) / Huff N Puff (HnP) / Bakken formation / Naturally fractured reservoir simulation / CO₂ utilization

CRediT authorship contribution statement

Saddam Mohammed Mohammed Nasser: Writing – original draft, Validation, Software, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Vivek Ramalingam: Writing – review & editing, Visualization, Validation, Supervision, Resources, Project administration, Methodology, Investigation, Formal analysis, Conceptualization. N. Madhavan: Writing – review & editing, Supervision.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The authors extend their gratitude to CMG Ltd. for providing access to their software and support throughout this study. We also acknowledge the Department of Petroleum Engineering, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India, for their valuable assistance and support. The first author would like to acknowledge Mr. Zakaria Gamal Ali Al-Semha for his support throughout the research work. Additionally, we thank all individuals who contributed to this work, whether directly or indirectly.

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