Monitoring land subsidence over a shallow gas reservoir in India using GPS

摘要

Subsidence is one of the most significant results of reservoir compaction due to extraction of gas/oil. It is difficult to predict the subsidence as it takes place well below the ground surface. Therefore, the prediction of subsidence is a challenging task. Subsidence measuring techniques should be such that they are capable of detecting even 1-mm level change in elevation. With the advancement of space technology, subsidence measurement is being carried out using Global Positioning System (GPS). Subsidence studies have been carried out over the shallow gas reservoir in Gujarat, India. A precise GPS network was established in 2004. Dual-frequency GPS receivers were used to collect the data. A significant amount of subsidence, 86 mm, was observed along with the horizontal displacement. Subsidence is correlated with the parameters responsible for subsidence. The coefficient of compaction is estimated from the subsidence. Subsidence is predicted over this area using empirical methods.