Impacts of Injection Induced Fractures Propagation in CO2 Geological Sequestration - Is Fracturing Good or Bad for CO2 Sequestration

In large-scale CO2 sequestration project the formation temperature decreases as huge amounts of relatively cool CO2 are injected. Injection induced fractures from injectors are facilitated as the critical pressure in the formation for fracturing is reduced by considerable thermo-elastic stress, which is proportional to the temperature difference between CO2 and reservoir. In this study, we analyze injection induced fracture growth and its impact on CO2 plume migration by a semi-analytical quasi-steady state model in the case that injection induced fractures are permitted by regulators. By parametric analysis with the model, geological properties and operating conditions are investigated to show their sensitivity on fracture growth and CO2 migration. This work provides analytical tools, which enable fast and simple screening of appropriate storage sites and of injection strategy, to predict fracturing and CO2 migration to avoid potential risks. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).