CCS project in Recôncavo Basin

Abstract

In August 2007, Petrobras and IFP have initiated a common research project on Carbon Capture Storage to determine the feasibility of CO2 injection and underground storage in an oil field located in Recôncavo Basin, a mature basin of northeastern Brazil. Petrobras has a strong experience of more than 15 years in the management of CO2 for EOR and aims to develop a long term vision of CO2 permanent storage. IFP is developing an ambitious R & D program on CCS for knowledge acquisition and technology development on the all chain, both under in-house projects and large collaborative efforts (EU project CASTOR, CO2STORE, CO2ReMoVe…). The aim of the first phase of the project is to take the opportunity of the existing CO2 injection for more than 15 years in the Buracica oil field for the development and validation of technology needed for CO2 storage. The main reservoir unit is predominantly constituted of eolic sandstone facies and is isolated from the other reservoirs by a shaly sand barrier. The cap rock is a thick clay formation. The CO2 was only injected in the top reservoir of the field. A unique program was design to combine detailed experimental and modeling work to assess the impact of CO2 injection on the storage. Both petrophysical and mineralogical changes will be assessed along the CO2 path within the reservoir from the injection to the production wells. One of the main goals is to asses the rock/fluid interactions due to CO2 injection and the different reactions that took place along the CO2 migration path within the reservoir and its impact on the cap rock. The aim is to provide a documented data set to enable reaction transport modeling benchmarking. To complement the standard monitoring measurements, geochemical monitoring will be initiated both at reservoir and surface level to ensure storage integrity after CO2 injection. The paper presents the main features of the project, as well as the results attained so far.