Major gas pipeline reopened after maintenance shutdown
Last July saw the return of natural gas flow through a major pipeline from Russia to Europe, following a 10-day shutdown for annual maintenance work. Seeing this supply restored was certainly a relief in the current geopolitical context in Eastern Europe. Nonetheless, across Europe, states and consumers are preparing to further reduce gas consumption. Gas represents about 20% of the European Union’s primary energy consumption and is the main source of domestic energy at 32%. Annual gas consumption entails €700 on average per year and household, constituting 2.5% of the average annual income of €27,911 in Europe. Ref. : www.acer.europa.eu.
Decrease of Energy Consumption in Europe over last 10 years
In this context, it is interesting to note that the energy consumption per capita in both Europe and North America has decreased since 2008 (Fig.1). This decrease was particularly conspicuous in 2020 during the pandemic of COVID-19, across all the regions. Conversely, the overall gas consumption worldwide is trending upward. We will see in the coming years if the downturn initiated during the pandemic endures.
Figure 1: Energy consumption in Gigajoule per capita per region (from bp Statistical Review of World Energy July 2021). Total CIS includes USSR, Georgia, Ukraine and the Baltic States, but excludes Estonia, Latvia and Lithuania prior to 1985 and Slovenia prior to 1990.
Decrease of Natural Gas Consumption in Europe
Regarding the consumption of natural gas, Europe has reduced its consumption since 2010, where it peaked at 22 exajoules (Fig. 2). In 2014, consumption reached its lowest level this century with 18 exajoules. Accordingly, continued reduction in gas consumption this year would follow a trend initiated more than ten years ago, and may yet decrease even further.
Figure 2: Gas consumption in Exajoules per capita per region against the left vertical axis and for the world against the right vertical axis (From bp Statistical Review of World Energy July 2021).
Rapid Gas Storage Injection Cycle in Europe This Year
In the current context, gas storage is particularly critical to servicing the gas demand during the winter months of 2022-2023. Gas storage follows a natural cycle with the seasons: Gas is injected into storage facilities from mid-April to early November when the demand for gas is low. On the other hand, gas is withdrawn from storage when the demand is higher with the arrival of winter in early November.
2022 sees no change to this cycle, with storage at its lowest level in April (Fig. 3). In fact, this year saw a particularly low storage level, ranging between 280 and 600 TWh, against the high level observed in 2020, measuring between 600 and 1000 TWh. Despite the low level in the first quarter of 2022, gas storage across Europe sits at 71% (at August 7th 2022), against last year where gas storage was just 59% in the same period. Should this trend hold steady gas storage should reach its highest level just prior to the end of September.
Figure 3: Gas Storage in Europe per year over 10 years.
Monitoring Gas Storage in Depleted Reservoirs
As of July 2021, about 170 gas storage facilities are active in Europe. Most European countries have a minimum storage requirement covering at least 15% of their annual gas consumption. The majority are from depleted fields, the others are in salt caverns or aquifers. Most of these facilities are onshore, with certain offshore exceptions in Spain and Turkey. The countries with the highest working gas volume are (in descending order) Germany, Italy and the Netherlands. In terms of number of facilities, Germany leads with 60 facilities, while Italy has 13 operational facilities, one in construction and seven planned.
The main challenges for gas storage in depleted reservoirs, as with those for CO2 capture, utilization and storage, are to ensure that injected fluids remain in the target zone, that the injection is done properly with low induced seismicity and finally that the caprock remains intact. Monitoring microseismic data helps to provide a dynamic and real-time view of potential changes in pressure within the subsurface. It is a crucial element in reservoir surveillance, complementing information given by other geophysical and geological data interpretation.
Should you need any help in monitoring gas storage or CO2 sequestration in depleted reservoirs using geophysical data, don’t hesitate to reach out.