Operations for underground reservoirs of geothermal energy extraction, CO2 storage, groundwater utilization, or waste fluid injection necessarily perturb the chemical and thermal equilibrium between native fluids and formations, potentially causing mineral dissolution and/or precipitation. Even though less studied, a much more significant problem is mineral precipitation, as, depending on the location of the mineral deposition, the ability of the reservoir to transmit fluids, solutes, and energy (i.e., the reservoir permeability) can reduce by many orders of magnitude.
The main goal of this PhD project is to investigate salt precipitation in natural and/or artificial fractures in granite, in order to understand the mechanisms that govern porosity and permeability changes that result from such pore-space modifications due to salt precipitation. By employing reactive flow-through experiments within an X-ray transparent pressure vessel, we can register the depositional patterns of precipitated salt after long-term flooding of dry, supercritical CO2 into brine-saturated fractured granite cores using X-Ray Computed Tomography. The porosity/permeability of the fractured granite cores before and after these experiments will be determined. These experimental observations will serve as calibration examples for the development of a numerical fluid flow and fluid-mineral reaction simulator, a critical step towards simulating and understanding the long-term behavior of geologic reservoirs.
Highly motivated candidates with an MSc degree in hydrology, hydrogeology, geochemistry, engineering geology, or a related field are encouraged to apply. The candidate should have proven knowledge of conducting laboratory experiments and/or developing/applying numerical models in a closely related field. Laboratory experience is a considerable advantage. He/she should be proficient in English and have excellent scientific writing and presentation skills. The candidate is an enthusiastic team player and has good communicational skills.
The PhD candidate is offered a one-year fulltime position with -at good performance- the prospect of an extension with a maximum of three years (in total 4 years fulltime). Benefits, working hours, salary, insurance and pension are subject to ETH Zurich standards.
For further information about the position please contact the project leader, Dr. Xiang-Zhao Kong at email@example.com (no applications) and visit our website https://geg.ethz.ch.
We look forward to receiving your application online (button “apply now” below), including a detailed CV, a motivation letter, diplomas, transcripts from all previous studies, and work certificates (if any) addressed to: ETH Zurich, Ms. Maja Bügler, Human Resources, CH-8092 Zurich. Evaluation of applications will start on March 1, 2017, and continue until the position is filled.
Applications can be done online at https://apply.refline.ch/845721/5150/pub/1/index.html