Predicting opening mode fracture patterns from diagenesis

Project Overview

All subsurface rocks contain fractures formed by stress and chemical processes. These fractures act as pathways, storage sites, or barriers for fluids such as water and mineral-rich solutions. Minerals precipitated from these fluids can fill fractures, helping keep them open while preserving evidence of the conditions under which they formed. As the global transition toward Net Zero accelerates, fractured rocks in the shallow crust are expected to play a key role in energy resources such as geothermal systems. To manage these resources effectively, scientists must predict how fractures are distributed at depth, since they strongly control fluid flow. However, predicting fracture patterns remains difficult because most existing models focus mainly on mechanical stress and rock strength measured in rapid laboratory tests. In reality, rocks often fracture at lower stresses when chemically active fluids are present, meaning current models fail to fully represent natural conditions.

The OpenFrac project aims to address this gap by developing a new model that links the mechanical growth of fractures with the chemical evolution of fluids within them. Experiments will examine how individual fractures develop in sandstone and limestone under varying fluid chemistry, temperature, and pressure. These results will inform numerical models that simulate more complex fracture networks over time. The model will then be tested using two UK case studies: sandstones linked to a geothermal pilot at the University of Leeds, and limestones with significant geothermal potential. The project will produce open-source models and datasets to support future research and the clean energy transition.