Abstract: Naturally fractured reservoirs are ubiquitous in the subsurface and, in the form of hydrocarbons and geothermal heat, they contain the bulk of the planet’s conventional energy that will provide the base load of our energy supply for decades to come. Characterising, modelling, and simulating naturally fractured reservoirs remains a major challenge for the energy industry: Subsurface data on fractures are sparse, fracture networks are multi-scale in nature, fracture apertures are difficult to constrain, and there are generally major uncertainties when characterising fracture properties. Fractures are also difficult to incorporate in conventional reservoir modelling and simulation workflows. This challenge is exacerbated by the fact that many of the key concepts to represent fractures in reservoir simulation models are decades old; indeed, it is frequently acknowledged that these concepts have major limitations. Yet, our limitations to reliably quantify the impact of fractures on reservoir flow processes greatly impacts our ability to harness vital energy resources more effectively.
This presentation will introduce some new and innovative concepts for modelling multi-phase flow processes in naturally fractured formations. Robust quantitative methods now allow us to develop a better understanding when fractures can be upscaled and represented by effective properties or when they need to be represented as explicit features in the reservoir model. Fast screening methods based on flow diagnostics enable us to quickly estimate how different fracture properties could impact reservoir performance, which allows us to select reservoir models that appropriately represent geological uncertainties and need to be studied further using detailed reservoir simulation. These reservoir simulation models can now employ novel concepts to represent the first-order physics for fluid exchange between fracture and matrix. Through a series of example applications, we will demonstrate how our perception of reservoir performance will change when these new modelling approaches are used.
Bio: Sebastian is the Director for the Institute of Petroleum Engineering (IPE) and the Energi Simulation (formerly known as Foundation CMG) Chair in Carbonate Reservoir Simulation. In the latter role, Sebastian heads the Carbonate Reservoir Group at IPE and serves as the Co-Director of the International Centre for Carbonates (ICCR). Sebastian joined the Institute of Petroleum Engineering (IPE) in 2006 as a lecturer and was promoted to senior lecturer in 2009 and as full professor in 2010. In 2017 Sebastian became the Director of IPE. Before joining IPE, he was a postdoctoral researcher at ETH Zurich from 2004 to 2006. Sebastian obtained his PhD degree in computational geosciences from the ETH Zurich in 2004 and holds an MSc degree in geosciences from Oregon State University. He was a visiting researcher at Aramco Services Company in Houston in 2015, at the Department of Earth Science and Engineering at Imperial College in 2006, and was a visiting fellow at the Department of Mathematics at Australia National University in 2001.
Together with the Carbonate Reservoir Group and colleagues at ICCR, Sebastian conducts fundamental and applied research that aims to improve our ability to characterise, model, and simulate hydrocarbon recovery from carbonate and fractured reservoirs. Sebastian’s group also started to map our learnings to wider geoenergy challenges such as geothermal energy or CO2 storage. Sebastian’s research activities include, but are not limited to, pore-scale studies of multi-phase and multi-component transport, micro-X-Ray CT visualisation of flow processes, upscaling flow and transport in fractured reservoirs, near-wellbore flow processes, feedback between carbonate reservoir architectures and fluid flow, numerical method development, enhanced oil recovery (particularly water-alternating gas injection), heat transport, and history matching.
For more information see https://researchportal.hw.ac.uk/en/persons/sebastian-geiger