Quick Screening for CO2-EOR as CCUS Technology: A Case Study in Recôncavo Basin

Abstract The carbon, capture, utilization and storage (CCUS) is a technology that allows the use of fossil fuels to energy generation and reduction the CO2 emissions to the atmosphere simultaneously. As part of this technology, CO2 can be used as an assessment for the oil industry, as well as an Enhanced Oil Recovery method by injecting CO2 in the oil reservoirs (CO2-EOR). An advantage of using the CO2-EOR is that oil and gas fields in production, either depleted or mature fields, can be targets to implement a storage project after the CO2 injection and oil production. However, not all fields are suitable to implement the CO2-EOR project and a screening process to select fields that can use the EOR method should carefully be chosen. To perform this screening is a hard task due to the need to gather enough data to the analysys, which the population to be studied might be huge, becoming difficult to collect all data needed. The aim of this paper is to present a quick screening process to select oil fields for CCUS, reducing the population studied. A study case and methodology was carried out, consisting in perform a quick screening and the analysys of reservoir data using a real fluid sample collected from a oil reservoir in Reconcavo basin. This data is primary data and was collected from a company. First, the fluid was characterized and the minimum miscibility pressure (MMP) was performed using the Rising Bubble apparatus (RBA). In addition, it was used CMG-Winprop to match the experimental and simulation data for MMP, and MMP was also calculated using the proper correlation developed for the Reconcavo. After that, the MMP was analysed by screening criteria to evaluate if the reservoirs criteria collected were significant for applying the process. The quick screening process was appropriate to show the potential of a basin to use CO2-EOR and to propose this method of previous studies at the Reconcavo were used as a guide. Even if the result is negative for the CO2-EOR, the studied reservoir can be used only for CO2 storage, and other criteria needed to be analyzed. Medium and small companies in the petroleum areas can use this quick process to do a preliminary study at the basin to select potential fields to apply the CO2-EOR, having a small population to study can reduce the costs of a big process that is the viability study of a project. Petroleum agencies and energy and technology departments can use this process as well to promote public energy policy and perform preliminary studies at the Reconcavo Basin to prove its potential to be used as sites for carbon sequestration to reduce CO2 emissions to the atmosphere.