Stefan Bachu¹

(1) Alberta Geological Survey, Edmonton, AB

ABSTRACT: Identification of Best Sites and Means for CO2 Sequestration in the Alberta Basin, Canada

Carbon dioxide sequestration in sedimentary basins is a means of reducing the release into the atmosphere of anthropogenic CO2 that is easy to implement as a result of the knowledge, technology and experience developed by the upstream oil and gas industry. Challenges are assessing the suitability of sedimentary basins for CO2 sequestration, and the selection of sites and means of sequestration through either one or a combination of: enhanced oil recovery (EOR), enhanced coalbed methane recovery (ECBMR), in depleted oil and gas reservoirs and uneconomic coal beds, in deep saline aquifers, and in salt caverns.

The suitability assessment and site selection are based on screening criteria that address the integrity, safety, capacity and duration of CO2 sequestration. These criteria relate to basin characteristics such as tectonism, geology, geothermics, hydrodynamics, resources and maturity, to CO2 sources, capture and transport, and to the properties of the CO2 and host rock and fluid at in-situ conditions. Using data that are usually collected by the energy industry, such as geophysical logs, analyses of reservoir fluids and formation water, drill stem tests, bottom hole temperature and core analyses, the geological space can be transformed into the CO2 space that can then be mapped and used in the identification of the most promising sites with significant storage capacity, and of sites that are unsafe because of CO2 phase instability. The methodology developed based on these criteria and approach was successfully applied to the identification of the most suitable CO2-sequestration sites in the Alberta basin.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado