Research Fellow
Dr Ryan Tonkin
Department of Engineering Science and Biomedical Engineering
ryan.tonkin@auckland.ac.nz
Ryan’s overarching research goal is to improve the numerical modelling tools and methodologies used in the geothermal industry.
About
Ryan Tonkin (he/him) is a research fellow in the Department of Engineering Science and Biomedical Engineering at the University of Auckland. His role includes researching geothermal engineering, lecturing for the Faculty of Engineering, international capacity building, and consulting. Ryan has a PhD in Engineering Science, specialising in geothermal engineering, and a BE (Hon) in Engineering Science.
Ryan’s overarching research goal is to improve the numerical modelling tools and methodologies used in the geothermal industry. He has developed a transient wellbore simulator capable of modelling complex flows of geothermal fluid in wells.
Using this simulator, he has modelled interesting transient phenomena, including start-up and shut-in processes, counter-flow, inter-zonal flow, airlifting and air compression. Other research interests include wellbore-reservoir coupling, modelling super-critical flow, and CO2 sequestration in geothermal reservoirs.
As an educator, Ryan lectures undergraduate courses for the Faculty of Engineering and supervises post-graduate research. He has also taught short courses for the Geothermal Institute on topics such as reservoir modelling and resource estimation.
Professional Experience
2023 - Present
Research Fellow
Geothermal Institute, University of Auckland, New Zealand
Research Fellow investigating numerical modelling of transient flow in geothermal wells and coupled reservoir-wellbore simulation. This role also includes undergraduate lecturing for the Faculty of Engineering, international capacity building (e.g., short courses and training), and consulting for domestic and international geothermal companies.
Qualifications
2017 - 2021
PhD, Engineering Science
University of Auckland, New Zealand
2014 - 2017
BE, Engineering Science (First Class Honours)
University of Auckland, New Zealand
Research
2017 - Present
Improved Transient Geothermal Wellbore Simulation
- Development of a novel transient geothermal wellbore simulator.
- Simulation of complex transient processes within the well, including wellbore storage, inter-zonal flow and rapid boiling.
- Simulation of geothermal well testing, including injection tests, pressure drop-off tests, heat-up surveys and production surveys to improve the interpretation of this well testing data.
2022 - Present
Coupled Geothermal Wellbore-Reservoir Simulation
- Developing methodologies for modelling coupled reservoir-wellbore dynamics to improve reservoir calibration and forecasting.
- Implementing tightly coupled methods for modelling near-wellbore processes.
- Researching robust, efficient methods for coupling geothermal reservoir models to hundreds of wellbore models.
2023 - Present
Net-Zero and Net-Negative Carbon Geothermal Reservoir Simulation
- Simulating net-zero and net-negative CO2 reinjection in geothermal reservoirs.
- Estimating CO2 flow from the reservoir to the atmosphere under CO2 reinjection.
- Design of optimal CO2 reinjection strategies for geothermal systems.
Teaching Experience
2023 - 2024
Lecturer – ENGSCI 773: Capstone Project
Faculty of Engineering, University of Auckland, New Zealand
Lecture series on wind turbine design, prototyping and testing.
2023 - 2024
Course Coordinator – Renewable Energy and Geothermal Project Management Short Course Series
Geothermal Institute, University of Auckland, New Zealand
Offered five times per year, our Renewable Energy and Geothermal Project Management courses are tailored for ASEAN and African nationals. These programs are backed by the Manaaki New Zealand Short-Term Training Scholarship.
2024
Trainer – ARGEO-C10 Pre-Conference Short Course (Tanzania)
Geothermal Institute, University of Auckland, New Zealand
Trainer for the two-day pre-conference short course on ‘Geothermal Resource Assessment’.
2024
Guest Lecturer – NGAP Pre-Conference Workshop
Geothermal Institute, University of Auckland, New Zealand
Guest lecturer discussing ‘Greenfield Resource Assessment using Numerical Reservoir Simulation’.
2024
Teaching Assistant – GEOTHERM 620: Geothermal Engineering
Faculty of Engineering, University of Auckland, New Zealand
Teaching assistant for reservoir modelling lectures and computer lab work.
Highlighted Papers
2025
Xie, J., Tonkin, R., Yeh, A., Wang, J., & O’Sullivan, M. (2025). Application of a geothermal wellbore simulator in evaluating an enhanced geothermal system. Geothermics, 125.
2023
Tonkin, R., O’Sullivan, J., Gravatt, M., & O’Sullivan, M. (2023). A transient geothermal wellbore simulator. Geothermics, 110.
2023
Tonkin, R., O’Sullivan, J., Gravatt, M., & O’Sullivan, M. (2023). Simulation of complex transient flows in geothermal wells. Geothermics, 108.
2023
Tonkin, R. A., O’Sullivan, M. J., & O’Sullivan, J. P. (2021). A review of mathematical models for geothermal wellbore simulation. Geothermics, 97.
Recent Collaborations
Address
L3, 70 Symonds St, Grafton, Auckland
New Zealand