Time series analysis of surface deformation related with CO2 injection by satellite-borne SAR interferometry at In Salah, Algeria

Abstract

History of surface deformation related with CO 2 injection at In Salah Gas Project, Algeria, was analyzed using satellite-borne Synthetic Aperture Radar (SAR) data. The Project is widely known as long term CO 2 storage project, of which injection has been performed since August 2004, with injected amount of 0.75 million tons CO 2 per year. Surface deformation around three injection wells, KB-501 through KB-503, has been analyzed by Differential Interferometry SAR (DInSAR), a promising remote sensing technique to detect surface deformation at an order of millimeters, using 47 scenes of ENVISAT ASAR spanning from July 2003 to May 2010. Amongst three injection wells, CO 2 injection at KB-502 has been temporarily shut down in July 2007, due to CO 2 breakthrough at an appraisal well KB-5 located 1.3 km to the northwest of KB-502. Permanent decommission of KB-5 was completed and the injection at KB-502 was restarted in November 2009. DInSAR analysis has revealed the surface displacement pattern between July 2007 and May 2010 around KB-502, which is thought to be related with shut-down and recommencement of CO 2 injection.