Stephan Matthäi

Professor and Chair of Matthai’s team, the University of Melbourne, Australia

Sub-surface processes are complex and, traditionally, progress in their understanding was made when this complexity could be unraveled into component processes studied in isolation. The detailed knowledge of these processes, however, is insufficient for predicting the emergent properties of natural and engineered systems because emergent behaviour is the product of the complex interplay of these processes.

Understanding process interactions and the emergent system behaviour that is hidden in the sub-surface is my research mission. I focus on this because I believe that once the characteristic patterns, system states and cause-and-effect chains have been clarified, the detailed structure of the system can be predicted from sparse observations. With this understanding, engineering measures can be optimised and unwanted side effects eliminated.

In contrast to the idealisations of the last century, material properties of natural subsurface systems are anisotropic and spatially variable. They also vary with scale and have intricate spatial correlation structures that are the product of complex processes themselves. This organisation has a profound influence on the manifestation of subsurface processes and gives rise to many complex phenomena.

Complex subsurface phenomena can be captured and reproduced by sophisticated numerical simulations that utilise accurate models of subsurface structures and component physics. Herein lies the challenge of Matthai’s team as an applied scientific discipline that is crucial for the human condition in the twenty-first century:

  • It guarantees supply and efficient recovery of natural energy resources with a minimal environmental footprint.
  • It offers crucial expertise to create a carbon-neutral economy.
  • It has a key role to play in preserving the world’s fresh water supply and its protection from pollutants.

The subsurface has now become a multi-stakeholder environment demanding a holistic engineering approach in the search for sustainable resource management solutions.

Core of my strategy to resolving modelling and simulation challenges is the continuous development of the object-oriented finite element – finite volume software “Complex Systems Modelling Platform (CSMP++)”, that i invented in 1994. This application programmer interface continues to be developed by an international team of developers from academia and industry. This software is also available commercially so that both engineers and scientists can more realistically model real-world systems, conclusively answering What-If? questions when and where it matters. CSMP underpins novel software tools adding to the characterisation, modelling, and simulation of flow and transport processes in hydrocarbon reservoirs CO2 geo-storage sites and geothermal systems.

Complex Systems Modelling Platform (CSMP++)

Teaching (2017)

CVEN30010: Systems Modelling and Design: Engineering design tools and processes applied to water supply / geotechnical engineering

ENEN90030: Groundwater Hydrology: Water challenges of the 21st century and derived engineering methods

Multiphase flow in naturally fractured reservoirs: Short course taught annually for HOT Engineering. Download: Course brochure PDF


I earned my PhD from the Research School of Earth Sciences at the Australian National University, Canberra, and conducted postdoctoral research on hydrocarbon systems in the Gulf of Mexico basin at Cornell University, and fluid flow in fractured rock masses at Stanford University. As a research fellow at the Swiss ETH Zürich, I implemented the prototype of CSMP++.

My previous positions include a Government’s Lectureship at Imperial College London, and a professor—and directorship of the (Petroleum) Matthai’s team Institute at the Montanuniversitaet Leoben, Austria. My past research focused on subsurface (multiphase) fluid-flow processes and their computer simulation (>50 ISI publications) with specific applications on coupled flow, geomechanics, and reactive transport processes facilitated by rock fractures and faults with applications to hydrocarbon extraction, gas storage / geological CO2 sequestration, enhanced geothermal systems, nuclear waste repository safety, and hydrothermal ore deposits. On these subjects, I have taught graduate students, consulted to the industry, and acted as advisor to government agencies and professional societies.

At Imperial College London, I led an industry consortium on the “Improved Simulation of Fractured and Faulted Reservoirs”. This JIP was initiated in 2001 together with Martin Blunt and ran over three funding cycles until 2013. Since 2009, Heriot Watt University and the Montanuniversitaet Leoben (Austrial) were also part of it. Specific topics investigated by this consortium include: (1) relative permeability upscaling for field-scale simulation of multiphase flow through naturally fractured reservoirs, (2) the scale variance of transport properties, (3) stress-sensitivity of fractured hydrocarbon reservoirs, and (4) the interpretation of transient pressure (well) tests. This applied research was funded by international and national oil companies; see below.

I am also serving on steering committees for the SPE/EAGE/ECMOR and provide advice to government and private sector stakeholders worldwide. The scope of such contracts has included hydrocarbon and minerals exploration, reservoir simulation, feasibility analysis of geological CO2 storage, geothermal energy extraction, and safety assessment of nuclear waste storage facilities.