Comparison of hydrocarbon and geothermal energy production in the Netherlands: reservoir characteristics, pressure and temperature changes, and implications for fault reactivation

Abstract

The Netherlands is in the midst of an energy transition with hydrocarbon production gradually declining, whereas the role of sustainable energy technologies is on the rise. One of these technologies is geothermal energy production from porous reservoirs at 1.5–3 km depth. As the number of geothermal projects increases, there is a growing concern that felt and/or damaging induced seismic events could occur as a result of geothermal operations. Over the last two decades, such events have occurred in the Netherlands due to gas production, notably in the Groningen gas field. However, the occurrence of felt events is limited to hydrocarbon fields in certain regions or reservoirs. Understanding where and for which plays these events are observed helps to estimate seismogenic potential for geothermal operations and other sustainable subsurface activities. Here, we summarise and review the main similarities and differences in terms of geological and geomechanical characteristics between the hydrocarbon and geothermal plays in the Netherlands, and we consider the differences in pressure and temperature changes. By doing so, we provide better insights into the factors that could play a role for fault reactivation and induced seismicity, and how these differ for hydrocarbon production and geothermal operations in the Netherlands. The review shows that geological characteristics for most geothermal target reservoirs are similar to those of hydrocarbon, albeit geothermal projects so far target higher porosity rocks than hydrocarbon reservoirs. On the other hand, pressure and temperature changes are very different, with significant depletion for hydrocarbon fields vs significant cooling around geothermal injection wells. The different operations result not only in different expected stress change magnitudes but also in a distinct spatio-temporal stress build-up on faults, which has implications for seismogenic potential and monitoring of these different operations.