Review of the Monitoring Applications Involved in the Underground Storage of Natural Gas and CO2

Abstract

Natural gas is an indispensable resource not evenly distributed in the world. The gas supply chain is characterized by large imbalances between supply and demand, where the underground gas storage (UGS) application plays a key role for creating strategic reserves, taking advantage of geological structures. On the contrary, human activities will require clean energy with near-zero greenhouse gas emissions to be environmentally viable. A key element of this strategy is the carbon capture and storage (CCS) application useful for confining CO2 into the geosphere to reduce anthropogenic emissions. The development of appropriate injection methods and long-term monitoring systems for leak detection of the underground storage of natural gas and CO2 is important to prevent negative effects, such as ground deformations and micro seismic events. In this work, a variety of monitoring applications were gathered and critically analyzed for a total of 60 scientific contributions spanning the world. This bibliographic work shows an analytical and statistical overview of the most common use of UGS and CCS, representing the different goals of these two applications and analyzing the main monitoring techniques used in the gathered contributions. Currently, UGS monitoring requires further development, especially through multidisciplinary approaches useful for identifying possible effects on the surface and gas leaks at depth; meanwhile, CCS solutions are still at the experimental stage, also because of the high costs for large-scale applications that still need specific research. The state of the art of these two very different practices can improve the further development of new monitoring approaches or additional methods.

Underground Gas Storage Monitoring Using Free and Open Source InSAR Data: A Case Study from Yela (Spain)

“…Rural areas, with rough terrain and vegetated areas, have associated low-phase coherence; this results in limited spatial coverage of InSAR measurement points [42]. Another limitation is the reduced presence of reliable and durable PS in heavily vegetated and complex mountainous areas [9] where many UGS sites are located. Despite these issues, InSAR technology is one of the best methods for monitoring UGS projects.…”

“…The constant increase in the number and capacity of UGS facilities has increased the importance of monitoring them. Indeed, UGS activities can induce vertical ground deformations, leading to subsidence (associated with natural gas extraction) or uplift (linked to natural gas injection) [9]. Continuous monitoring is paramount to ensure caprock integrity and the efficiency and longevity of injection/withdrawal wells.…”

“…Notably, the efficacy of InSAR in monitoring UGS activity is evident in its ability to detect vertical ground deformation due to UGS operations through time series analysis [5]. As a result, InSAR is fast becoming a standard technology adopted in many UGS projects across Europe, offering wide-area monitoring at a fraction of the cost of traditional methods e.g., [5,[9][10][11]. Additionally, ground deformation data can be linked to reservoir parameters through geomechanical models [12].…”

Material Balance Method and Dynamic Pressure Monitoring for Water-Bearing Gas Reservoirs with CO2 Injection

“…Monitoring tools, monitoring time, and monitoring methods will also affect the monitoring effect. It is unrealistic to achieve monitoring of the CO 2 storage status through only one aspect, and to achieve better monitoring results, a combination of multi-disciplinary techniques in monitoring is needed [16]. Improvements in monitoring tools are also necessary.…”