PsInSAR based land subsidence estimation of Burgan oil field using TerraSAR-X data

Abstract

Oil extraction over the years has increased tremendously resulting in land subsidence, which is a slow and gradual process and has long-term effects on ecohydrology and climate. For efficient measurement of land subsidence phenomenon due to oil extraction, an advanced PsInSAR technique was used in this study which overcame the obstacles such as temporal and geometrical decorrelation, phase delay due to atmospheric variation. The primary objective of the present study is to investigate the potential of PsInSAR technique to estimate total land subsidence in Burgan oil field, Kuwait, on a multitemporal scale from 2008 to 2011. A total of 26 datasets TerraSAR-X interferometric datasets were acquired from 31st January 2008 to 4th February 2011. Permanent Scatter Candidates (PSC) were selected based on amplitude stability index. Atmospheric Phase was estimated and removal of Atmospheric Phase Screen was carried using ensemble coherence. To measure the displacement between 31st January 2008 and 4th February 2011, a spatio-temporal displacement map was generated and overlaid on Google Earth to mark the areas of oil wells in Burgan oil field where subsidence has taken place. The total amount of subsidence was obtained from Integrated Cumulative Displacement Map, the value of which was estimated to be 10mm/year and an average of 25–30mm per 3 years. The land subsidence outcome of this study for three-years times was compared with already existing literature based results to show the potential of PsInSAR for subsidence mapping due to oil extraction. PsInSAR technique for land subsidence monitoring showed significant improvement in results after correcting for the atmospheric phase errors.