Integrated Modelling and Approach for Carbon Capture and Storage Wells Design and MMV Philosophy

Abstract This paper highlights the significance of designing CCS injector wells, weighing the potential flow assurance and operational risks during the injection phase, hence drawing the key philosophies to incorporate in the MMV plan as early as during the Storage Development Plan (SDP) and Field Development Plan (FDP) project stages. This case study stems from sequestration case study of permeate transport from a producing field to store at a depleted gas reservoir. The process includes permeate separation, hydrocarbon recovery, compression, pipeline for transportation and injection at the targeted CCS sequestration site. Therefore, it is quintessential to conduct comprehensive project specific risk assessment that accounts for the complexity of the case study to mitigate the risk of operational disruptions following the first injection. In such cases any operational upsets at the CCS site could have cascading effects impacting production downtime across all producing fields lined up for carbon sequestration. Firstly, the case study will focus on risk assessment related to wells, emphasizing the importance of early identification and analysis of potential risks to ensure their integration into well design. This proactive approach is critical for reducing the overall project risk and uncertainty. The study paves way for selecting appropriate completion accessories setting depth and wellhead material specifications in accordance with API 6A temperature classification guideline. Transient modelling approach was adopted, and multiple scenarios were tested to determine the optimal well design based on permeate characteristics and reservoir fluid composition. Secondly, the study case also emphasizes risk assessment related to potential flow assurance challenges such as asphaltene precipitation risk, hydrates risk and salt precipitation risk, evaluating their impact while identifying control barriers and safeguarding measures designed to prevent operational upsets. Classical reservoir analysis techniques including contact movement and historical reservoir production evaluation of depleted gas field along with fluid modelling were employed to access the potential flow assurance risks. Finally, recommendations were developed that best align with this case study outcome given the information available at this stage.