Contact: Gülce Kalyoncu
Currently, almost one third of the global energy demand is provided by renewable energy sources. However, using renewables with intermittent output (wind and solar) to their full potential creates a need for energy storage technologies and better grid management. The main idea is to store energy during times of energy surplus and deliver it to the electricity grid during times of high demand. Geological structures, such as saline aquifers and depleted hydrocarbon reservoirs, possess large volumes of readily available pore space that can be used to store energy in the form of compressed air or hydrogen gas. However, these operations require the injection of gasses into pores that are typically filled with highly saline brine. Then, some of the brine originally present inside the rock can evaporate, which can lead to salt precipitation. This can cause blockage in pores and throats, reducing the gas permeability, potentially leading to a critical damage to the injection well.
The objective of this study is to investigate the effects of salt precipitation in rocks at pore, core, and field-scales. This is based on micro-computed tomography (μ-CT) images captured during salt precipitation experiments, and analyzed using numerical models (pore network models, reservoir simulators). The goal is to develop better salt precipitation risk predictions during renewable energy storage. The findings are also highly relevant to geological CO2 sequestration.