Análise do desempenho econômico de projeto recuperação avançada de petróleo com injeção de CO2 (EOR-CO2) através de indicadores financeiros: panorama brasileiro

Abstract

Advanced hydrocarbon recovery (EOR) is one of the options associated with CO2 capture and storage (CCS) technology. In EOR/CCS projects, CO2 is injected into mature/depleted oil fields in order to improve production indicators and recover additional volumes of oil, with environmental benefit through CO2 storage. However, the EOR-CO2 project involves several steps (capture to injection), uncertainties and is an expensive alternative, linked to costs, whether controllable and/or non-controllable. Thus, due to the density of investments in EOR CO2 projects and in order to encourage decision-making, there is a need to technically and economically evaluate these projects. In this perspective, this research analyzed several parameters/methods of quantification of the financial costs involved in EOR-CO2 projects, with the objective of finding a more complete model for the analysis of economic viability, in relation to financial indicators, and suitable for Brazil. For the application of the economic model, the projects developed by Silva et al. (2010), who studied the revitalization of mature/marginal reservoirs for six scenarios submitted to CO2 injection, considering the productive data from the numerical simulation. It was also proposed a sensitivity analysis of some parameters and their impacts on the Net Present Value (NPV) for the project scenarios studied. The oil production and CO2 injection data were used in the cash flow, which was submitted to the evaluation of financial indicators, being them the Net Present Value (NPV), Internal Rate of Return (IRR) and Payback, as well as in compliance with the Minimum Attractiveness (MAR). Of the six scenarios analyzed, Case C with 5 wells, 3 completed layers and a Recovery Factor (RF) of 79.73% had the highest NPV, despite not having the largest number of wells and RF. Case E with 6 wells, 2 layers completed and RF of 67.71% showed the lowest NPV, even though it did not have the lowest number of wells and the lowest RF of the scenarios. The results showed that the economic evaluation can result in different choices of the production scenario regarding technical parameters such as RF, number of wells and accumulated oil volume. Already through the sensitivity of some parameters such as barrel price, minimum rate of attractiveness, cost of CO2 credit and value of excess CO2 taxation, in response to NPV, it was observed that the first two had a considerable impact on NPV. However, the taxation of excess CO2 was not very expressive in this study, with negligible values. As for the MAR, it proved to be sensitive and capable of reversing the attractiveness of scenarios C and F. It is noteworthy that Case F differs from Case C due to the RF of 79.82% and has an extra layer completed. For low MAR values, case F had a higher NPV while for high MARs, case C had the best NPV. For the price of a barrel, it proved to be very sensitive in NPV. For all scenarios evaluated, for low prices of a barrel around $9, they proved to be unprofitable with NPVs were negative.