Modelo dinâmico de seqüestro geológico de CO2 em reservatórios de petróleo

Abstract

The geologic formations, which can be utilized for CO 2 storage include: deep saline aquifers, oil and gas reservoirs and coal bed reservoirs. The fluids in the subsurface fill the porous rock as occurs with water, oil, natural gas, carbon dioxide, among others. In these formations, carbon dioxide is stored by different trapping mechanisms; the exact mechanism depends on the type of rock. The main mechanisms are: hydrodynamic trapping, solubility trapping and mineral trapping. Among the geologic formations, oil reservoirs are strong candidates to be used in the reduction of carbon dioxide in the atmosphere due to the technological knowledge acquired by the oil industry. These reservoirs are proved geologic traps with capacity to retain fluids and gases for long term. The CO 2 injection technique for enhanced recovery is a common practice in the oil industry and it can be used in carbon sequestration. The storage of some part of the injected gas in reservoirs submitted to Enhanced Oil Recovery operations is a direct consequence of CO 2 utilization since the gas produced with the oil be captured and re-injected in the reservoir. This work presents a global dynamic model of the carbon sequestration process in enhanced oil recovery operations in a typical mature oil reservoir aiming to quantify the real contribution of the stored gas.