Natural and industrial analogues for leakage of CO

Authors: Jennifer L Lewicki Jens Birkholzer ChinFu Tsang

Publish Date: 2006/10/07

Volume: 52, Issue: 3, Pages: 457-

PDF Link

Abstract

Instances of gas leakage from naturally occurring CO2 reservoirs and natural gas storage sites serve as analogues for the potential release of CO2 from geologic storage sites This paper summarizes and compares the features events and processes that can be identified from these analogues which include both naturally occurring releases and those associated with industrial processes The following conclusions are drawn 1 carbon dioxide can accumulate beneath and be released from primary and secondary shallower reservoirs with capping units located at a wide range of depths 2 many natural releases of CO2 are correlated with a specific event that triggered the release 3 unsealed fault and fracture zones may act as conduits for CO2 flow from depth to the surface 4 improperly constructed or abandoned wells can rapidly release large quantities of CO2 5 the types of CO2 release at the surface vary widely between and within different leakage sites 6 the hazard to human health was small in most cases possibly because of implementation of postleakage public education and monitoring programs 7 while changes in groundwater chemistry were related to CO2 leakage waters often remained potable Lessons learned for risk assessment associated with geologic carbon sequestration are discussedWe are grateful to CM Oldenburg S Brennan and an anonymous reviewer for constructive review of this manuscript We thank the US Environmental Protection Agency Office of Water and Office of Air and Radiation for funding this study under an Interagency Agreement with the US Department of Energy at the Lawrence Berkeley National Laboratory Contract No DEAC0205CH11231

Keywords: