Project Title: Pore scale imaging, analysis, and data-driven pore-scale modelling

Supervisor: Professor Martin Blunt

Email: m.blunt@imperial.ac.uk

Many of the scientific challenges associated with a transition to a net-zero carbon economy by 2050, to avoid dangerous climate change, are associated with the flow of fluids deep underground in porous rock. It is in these rocks that carbon dioxide can be stored, to offset emissions from fossil fuels.  Understanding, managing and designing this process requires a knowledge of how fluids flow at the micron-scale in the pore space.  At Imperial College we have pioneered advanced X-ray imaging techniques to observe flow patterns inside porous media, as shown in the picture above.

Applications are invited for a Ph.D. studentship in the Department of Earth Science and Engineering.  The successful candidate will have the opportunity of working with a dedicated team involving various academics and Departments within an industrially-funded project “Digital Rocks”.  You will use  image-based digital technology to study CO₂ storage and enhanced oil recovery. Our aim is to develop unique measurement and modelling capabilities to stretch our fundamental understanding of rock properties, fluid properties and multiphase fluid flow in reservoirs, to enable radical enhancements in the design and prediction of flow processes underground.

You will work as part of an integrated, friendly and supportive team of scientists and engineers from all round the world who use innovative X-ray imaging techniques, image analysis and modelling to understand how fluids flow in porous media.

The main objectives of the PhD project will be to:

• Demonstrate an improved workflow combining imaging and measurement of multiphase flow properties.
• Provide benchmark datasets on displacement processes under a variety of conditions.
• Refine and improve the measurement of interfacial curvature and wettability and to explore the use of machine learning algorithms in image analysis.
• Analyse the datasets to track displacement processes and occupancy on a pore-by-pore basis together with measurements of capillary pressure and relative permeability.
• Acquire time-resolved datasets at synchrotron sources to obtain insights into the dynamics of displacement and to provide robust calibration for models.

In addition, the successful candidate will be expected to submit publications to refereed journals and to present their findings at major international conferences and to the sponsors. 

The applicants should also have a proven aptitude for practical, experimental work and a genuine passion for research. Applicants are expected to have obtained (or be heading for) a first or upper-second degree at master’s level (or equivalent) in any relevant engineering or physical science discipline and be highly motivated.

Funding is available for a period of 3.5 years and covers both stipend and tuition fees. Applicants must qualify as ‘home’ students for fees purposes (EU citizens must start on or before 31 July 2021 to satisfy this criterion)

Applications should be made through the College’s online application system:

http://www.imperial.ac.uk/study/pg/apply/how-to-apply/

Important information about the College’s PhD application process can be found on the following page: http://www.imperial.ac.uk/study/pg

Informal enquiries about the post can be made to Professor Martin Blunt (m.blunt@imperial.ac.uk)

Project Title: Porous media flows of complex rheology 

Supervisor: Dr Ronny Pini, Department of Chemical Engineering

Email: r.pini@imperial.ac.uk

Introduction

Aqueous polymer solutions used for Enhanced Oil Recovery (EOR) undergo complex flow processes, thereby complicating the prediction of the displacement and, accordingly, the design of the operation itself. Partial retention, accelerated flow and mechanical degradation are commonly observed during the transport of polymer solutions through rocks, in addition to the characteristic rheological behaviour in their pore structure. The objective of the PhD is to develop improved understanding of polymer flow through porous media under the conditions of temperature and pressure typical of hydrocarbon reservoirs.

Methodology

The PhD project will exploit state-of-the-art experimental facilities available at Imperial to provide mechanistic insights on porous media flows of complex rheology. To this end, core-flooding experiments augmented by 4D imaging of the flow will be carried out to reveal the underlying mechanisms of polymer flooding. Two imaging methods will be deployed, namely X-ray Computed Tomography – to provide detailed spatial information of fluid phase saturation distribution, and Positron Emission Tomography – to unravel the dynamic evolution of the polymer slug as it travels through the sample. We will test different polymer-solutions (synthetic and bio-polymers) in a range of brine salinities and rock types. Experimental parameters will be varied systematically, so as to quantify and decouple the effects of polymer rheology, retention and degradation. Suitable mathematical models of transport will be evaluated against the experimental observations.

Expected Results

The PhD project will produce a rich data-set of dynamic polymer/water, polymer/oil and polymer/polymer displacements for different combinations of polymer- and rock-types, focusing on samples with distinct multi-scale heterogeneity. The data will be used to quantify the polymer retention characteristics for the systems studied above. The transport process will be evaluated by computing relevant metrics of the displacement from the 4D imagery. A systematic comparison will be carried out between the experimentally-derived metrics and those predicted using the Advection-Dispersion Equation (ADE) and its modification to account for retention and/or regions of limited mobility. The results will be published in several scientific papers and presented at relevant conferences.

Applicants

Funding is available for a period of 3.5 years and covers both stipend and tuition fees. Applicants must qualify as ‘home’ students for fees purposes (EU citizens must start on or before 31 July 2021 to satisfy this criterion). Applicants should hold or expect to obtain a first-class honours degree at Master’s level (or equivalent) in chemical engineering, another branch of engineering or a related science.

Informal enquiries about the post can be made to Dr Ronny Pini (r.pini@imperial.ac.uk).

Project Title: Pore-to-field reservoir characterisation for CO2 storage

Supevisor: Dr Sam Krevor

Email: s.krevor@imperial.ac.uk

Project Title: Interfacial properties of live reservoir fluids 

Supervisor: Professor Martin Trusler

Email: m.trusler@imperial.ac.uk

Introduction

The multi-phase flow properties of fluids within a porous medium are strongly influenced by the thermophysical properties of those fluids and their wetting behaviour towards the porous solid. The properties of importance include the density and viscosity of individual fluid phases (oil, brine and gas), the interfacial tension between different fluid phases and the contact angle formed between fluid-fluid interfaces and the surfaces of the porous medium. Understanding these properties at a fundamental level and establishing their connection with fluid flow is essential for effective reservoir processes such as hydrocarbon recovery and CO₂ storage. The objective of the PhD will be to develop improved understanding of interfacial and other properties of oils, brines and hydrocarbon gases under the conditions of temperature and pressure typical of hydrocarbon reservoirs.

Methodology

A key feature will be a focus on ‘live’ fluids, i.e. oils and brines saturated with light gases at reservoir conditions. Therein lies both the scientific interest and the experimental challenges. The PhD project will exploit state-of-the-art experimental facilities available at Imperial for the measurement of key properties of live reservoir fluids at reservoir conditions. Several different experimental techniques will be used to measure bulk properties (density and viscosity), fluid-fluid interfacial tensions and fluid-fluid-mineral contact angles.  The results of the experimental investigation will be rationalised in terms of the detailed thermodynamic models that can subsequently be used to make predictions of properties under conditions not studies experimentally.

Expected Results

The project will characterise a set of prototype oils and brines (with methane as the solution gas) in detail. These data will permit the evaluation and testing of thermodynamic models and, ultimately, the development of new methodologies for characterising the properties of reservoir fluids based on a much-smaller amount of experimental data. Interfacial tensions and contact angles are strongly affected by surface-active components present in crude oils and the study will illuminate the influence of such components at reservoir conditions. The results will be published in several scientific papers and presented at relevant conferences.

Applicants

Applicants should hold or expect to obtain a first-class honours degree at Master’s level (or equivalent) in chemical engineering, another branch of engineering or a related science.

Project Title: Multi-scale porosity in carbonate rocks 

Supervisor: Dr. Ronny Pini, Department of Chemical Engineering

Email: r.pini@imperial.ac.uk

Introduction

The application of digital technology to the study of carbonate rocks is from being mature. Opportunities to expand its domain of applicability are high, particularly in the context where a better understanding of the spatial distribution of microporosity is integrated with observations of transport and multi-phase displacement processes. A critical challenge is the development of advanced experimental protocols that probe the pore-scale structure in carbonates in a continuous range across over seven decades of length scales (from 10 nm to 10 cm) and to integrate information at these different scales. The objective of the PhD is to develop and test an experimental workflow to quantify microporosity in carbonate rock cores, spatially.

Methodology

The PhD project will exploit state-of-the-art experimental facilities available at Imperial College London. We will consider three-dimensional X-ray tomographic microscopy and build a dedicated setup to accommodate the rock sample and internal standard(s) to account for any drift in the measured attenuation coefficients. Various techniques will be evaluated systematically, including (i) standard gas adsorption tests, (ii) gas adsorption imaging experiments using a range of probe gas molecules (including strongly attenuating X-ray agents, e.g., Kr, Xe), (iii) differential imaging and (iv) confocal microscopy. A systematic approach to sample selection will be applied – from model systems towards rock systems in their reservoir state. The obtained imagery will be used to build digital rock models and to study the effect of multi-scale porosity on transport by means of pore-network modelling approaches.

Expected Results

The PhD project will produce a rich data-set, including 3D imagery of various rock types characterised by distinct degree of microporosity. The measurements will be used to quantify the scale and extent of both intra- and inter-granular porosity of the rocks, and their spatial variability. The obtained imagery will be used to compute additional relevant properties, such as effective mass transfer/diffusion, by combining it with suitable numerical models of transport. The results will be published in several scientific papers and presented at relevant conferences.

Applicants

Funding is available for a period of 3.5 years and covers both stipend and tuition fees. Applicants must qualify as ‘home’ students for fees purposes (EU citizens must start on or before 31 July 2021 to satisfy this criterion). Applicants should hold or expect to obtain a first-class honours degree at Master’s level (or equivalent) in chemical engineering, another branch of engineering or a related science.

Informal enquiries about the post can be made to Dr Ronny Pini (r.pini@imperial.ac.uk)