The Influence of CO2 Injection Timing and Well Placement on Storage Indicators in a Producing Natural Gas Reservoir with High CO2 Content

Carbon capture and storage is recognized as the best method for CO2 emission mitigation in cases where the emissions cannot be avoided by switching to renewable energy or by increasing efficiency. In the Republic of Croatia, there are a number of gas-condensate reservoirs with a high content of CO2 that are adequate candidates for CO2 storage. The injection starts at selected different points before the end of production and might bring financial benefits as a result of CO2 injection patterns and efficient permanent storage. Employing a model of a typical reservoir, various scenarios of CO2 injection are examined to assess the impact of injection well positioning and timing on the reservoir’s sustainability for permanent CO2 storage. The main indicators used for the assessment are additional hydrocarbon recovery, retention, and storability.