Numerical study of CO2-injection borehole integrity with consideration of thermo-mechanical effects

Abstract

Underground storage of CO2 is one efficient solution to reduce CO2 emissions and to slowdown the greenhouse effect. The objective of the CLEAN project is to investigate the feasibility of CO2 storage in a depleted oil and gas reservoir. For this purpose, one part of the onshore-gas field "Altmark gas field" has been provided for the research. The objective of this paper is to verify the integrity of the research borehole during cooler CO2-injection and to validate the closure of the injection induced cracks in cement due to salt creep by using numerical simulator FLAC3D. After numerical simulation, the critical value of the decreasing temperature in different segments was indicated. It was also proved that, the creep behavior of salt rocks can indeed close the cracks in the cement which leads to the recovery of borehole integrity. © Springer-Verlag Berlin Heidelberg 2013.