Radar Interferometry as a Comprehensive Tool for Monitoring the Fault Activity in the Vicinity of Underground Gas Storage Facilities

Abstract

Underground gas storage facilities are an important element of the natural gas supply system. They compensate for seasonal fluctuations in natural gas consumption. Their expected lifetime is in tens of years. Continuous monitoring of underground gas storage is therefore very important to ensure its longevity. Periodic injection and withdrawal of natural gas can cause, among other things, vertical movements of the terrain surface. Radar interferometry is a commonly used method for tracking changes in the terrain height. It can register even relatively small height changes (mm/year). The primary aim of our research was to verify whether terrain behavior above a relatively deep underground gas storage can be monitored by this method and to assess the possibility of detecting the occurrence of anomalous terrain behavior in an underground gas storage area such as reactivation of faults in the area. The results show a high correlation between periodic injection and withdrawal of natural gas into/from the underground reservoir and periodic changes in terrain height above it (the amplitude of the height changes is in centimeters), which may allow the detection of anomalous phenomena. We documented special behavior of storage structures in the Vienna Basin: the areas adjacent to the underground gas storages show exactly the opposite phase of vertical movements, i.e., while the terrain above the underground reservoirs rises as natural gas is injected, the adjacent areas subside, and vice versa. Based on the analysis of geological conditions, we tend to conclude that this behavior is conditioned by the tectonic fault structure of the studied area.

Reply on CC1

“…The IFG-3 and IFG-4 are merged in one image due to the AoIs, which are located between two different image acquisitions in orbit number 66. In order to monitor the dam and bridges, it is highly recommended to use PS-InSAR for regional and local ground deformation detection (Hooper et al, 2004;Rapant et al, 2020;Sanabria et al, 2014). `8…”

Displacements Monitoring over Czechia by IT4S1 System for Automatised Interferometric Measurements Using Sentinel-1 Data

“…Further examples of application of the on-demand processing outputs of IT4S1 over Czech areas were documented in our previous works, further works are anticipated as well. In the case of an underground gas storage facility in the Tvrdonice area, seasonal deformations were identified and their correlation to the gas reservoir processes was studied in [37]-there we identify a change of the seasonal deformations behaviour behind a tectonic fault. Earlier, we have attempted to identify slope instabilities around Ostravice [29], concluding about unreliability of both PS and SB outputs in the area of dense vegetation for detection of slow slope instabilities.…”

Displacements Monitoring over Czechia by IT4S1 System for Automatised Interferometric Measurements Using Sentinel-1 Data

“…Examples of application of the on-demand processing outputs of IT4S1 over Czech areas were documented in previous works. In the case of an underground gas storage facility in the Tvrdonice area, seasonal deformations were identified and their correlation to the gas reservoir processes was studied in [32] -there we identify a change of the seasonal deformations behaviour behind a tectonic fault. We have attempted to identify slope instabilities around Ostravice [26], concluding about unreliability of both PS and SB outputs in the area of dense vegetation for detection of slow slope instabilities.…”