Foam Improved Oil Recovery: Effects of Flow Reversal
Lead Research Organisation:
University of Strathclyde
Department Name: Chemical and Process Engineering
Abstract
The context of this project is improved oil recovery.
In petroleum extraction operations, only a fraction of the oil manages
to flow out of a reservoir under the reservoir's own pressure.
After that, petroleum engineers resort to injecting fluids into the
reservoir to try to push out remaining oil.
Foam (consisting of bubbles of gas dispersed in aqueous surfactant
liquid) is a promising candidate injection fluid to achieve that.
Because oil and gas reservoirs are difficult to access (being
underground and often in harsh environments), it is generally not
possible to observe directly how an injected foam flows inside them.
Having a mathematical model of the reservoir flow is therefore
very valuable.
This project will develop one such model, so called ``pressure-driven
growth'', which is particularly computationally efficient, as it
focusses just on a foam front as it propagates through the reservoir,
rather than on the state of the entire reservoir away from the front.
Despite its computational efficiency, the pressure-driven growth model
currently has a number of limitations.
One such limitation is that the model is not currently able to
describe a situation in which the foam front undergoes a sudden change
in direction.
This is an issue since, during foam improved oil recovery, foam that
is already within the reservoir after a period of foam injection into
a given well, may change its direction of motion if a new adjacent
injection well is brought online.
The purpose of this project is to adapt the pressure-driven growth
model to describe situations such as this.
However in order to do this, we need first to explore another model
(namely so called ``fractional flow'' theory) which underpins
pressure-driven growth.
Fractional flow theory actually contains a finer level of detail than
pressure-driven growth does, providing very specific information about
exactly what is happening at a foam front at which gas and liquid
meet.
Such information includes how gas and liquid fraction profiles vary
across the foam front, how thick the front is, and how mobile it is:
all this information then feeds into parameters governing the less
detailed description given by pressure-driven growth.
Our aim therefore is to explore how fractional flow theory responds to
changes in flow directions, and to use the fractional flow results to
re-parameterise pressure-driven growth.
Having achieved this, our objective will be to test the
re-parameterised pressure-driven growth model in a number of petroleum
engineering situations that involve flow direction changes.
Results from the model will also be compared against a much more
computationally intensive ``entire reservoir'' approach, which is
conventionally employed in petroleum engineering.
The main application area that will benefit is of course oil and gas,
with the oil and gas industry managing to recover more fluids and
hence generate more revenue from existing sites.
In certain cases, e.g. for very mature oil fields, employing foam
improved oil recovery might even make the difference between keeping a
field open or needing to shut it down.
By using modelling tools predicting how foam improved oil recovery
proceeds, oil companies will be able to plan and optimise operations,
prior to performing any costly drilling, thereby limiting the need to
resort to trial and error approaches.
Although benefits of the project focus mostly on oil and gas, wider
benefits are also anticipated.
The front propagation models that we will study for foam fronts in oil
reservoirs are remarkably similar to models governing a number of
other systems, including mechanics of solid-liquid suspensions,
supersonic flow through air, spread of epidemics, pedestrian flow and
fire front propagation, amongst others.
New insights into other systems such as these can therefore derive
from the project.
In petroleum extraction operations, only a fraction of the oil manages
to flow out of a reservoir under the reservoir's own pressure.
After that, petroleum engineers resort to injecting fluids into the
reservoir to try to push out remaining oil.
Foam (consisting of bubbles of gas dispersed in aqueous surfactant
liquid) is a promising candidate injection fluid to achieve that.
Because oil and gas reservoirs are difficult to access (being
underground and often in harsh environments), it is generally not
possible to observe directly how an injected foam flows inside them.
Having a mathematical model of the reservoir flow is therefore
very valuable.
This project will develop one such model, so called ``pressure-driven
growth'', which is particularly computationally efficient, as it
focusses just on a foam front as it propagates through the reservoir,
rather than on the state of the entire reservoir away from the front.
Despite its computational efficiency, the pressure-driven growth model
currently has a number of limitations.
One such limitation is that the model is not currently able to
describe a situation in which the foam front undergoes a sudden change
in direction.
This is an issue since, during foam improved oil recovery, foam that
is already within the reservoir after a period of foam injection into
a given well, may change its direction of motion if a new adjacent
injection well is brought online.
The purpose of this project is to adapt the pressure-driven growth
model to describe situations such as this.
However in order to do this, we need first to explore another model
(namely so called ``fractional flow'' theory) which underpins
pressure-driven growth.
Fractional flow theory actually contains a finer level of detail than
pressure-driven growth does, providing very specific information about
exactly what is happening at a foam front at which gas and liquid
meet.
Such information includes how gas and liquid fraction profiles vary
across the foam front, how thick the front is, and how mobile it is:
all this information then feeds into parameters governing the less
detailed description given by pressure-driven growth.
Our aim therefore is to explore how fractional flow theory responds to
changes in flow directions, and to use the fractional flow results to
re-parameterise pressure-driven growth.
Having achieved this, our objective will be to test the
re-parameterised pressure-driven growth model in a number of petroleum
engineering situations that involve flow direction changes.
Results from the model will also be compared against a much more
computationally intensive ``entire reservoir'' approach, which is
conventionally employed in petroleum engineering.
The main application area that will benefit is of course oil and gas,
with the oil and gas industry managing to recover more fluids and
hence generate more revenue from existing sites.
In certain cases, e.g. for very mature oil fields, employing foam
improved oil recovery might even make the difference between keeping a
field open or needing to shut it down.
By using modelling tools predicting how foam improved oil recovery
proceeds, oil companies will be able to plan and optimise operations,
prior to performing any costly drilling, thereby limiting the need to
resort to trial and error approaches.
Although benefits of the project focus mostly on oil and gas, wider
benefits are also anticipated.
The front propagation models that we will study for foam fronts in oil
reservoirs are remarkably similar to models governing a number of
other systems, including mechanics of solid-liquid suspensions,
supersonic flow through air, spread of epidemics, pedestrian flow and
fire front propagation, amongst others.
New insights into other systems such as these can therefore derive
from the project.
Planned Impact
This project on foam improved oil recovery will generate impact on a
number of levels.
First of all, the project will generate new knowledge on how foam
injected into an oil and gas reservoir manages to push oil out,
particularly in situations when the direction of the foam flow changes
as a new injection well comes online. Specifically we will develop
models that will allow petroleum engineers to optimise oil recovery
from existing reservoirs, with the models thereby informing optimal
placement of wells. Given that in oil extraction operations, drilling
a well in the wrong place can be a costly mistake, having robust
models of where and when to drill, will be of immense value to the oil
industry.
Although the work is set in the context of oil recovery, the knowledge
that we generate will have wider impact beyond this field. Indeed the
set of mathematical models we need to study arise not just in
petroleum engineering applications but in many other contexts as well,
including suspension mechanics, supersonic flow, spread of epidemics,
pedestrian flow and fire front propagation. The knowledge generated
in the present project will therefore have impact across the wider
applied mathematics community, and even beyond: ability to model
propagation of a bushfire front for instance, is of great importance
in regions affected by drought exacerbated by climate change.
In addition to impacting upon knowledge, the project will also impact
on people. Specifically it will contribute to the pipeline of
talented researchers working in the area of engineering and applied
mathematics. The project will achieve this not only directly (i.e. by
providing the named researcher, Carlos Torres, with postdoctoral
funding) but also indirectly: after completion of the project, Torres
will return to an academic post in his home country (Chile) where he
will be able to encourage a new generation of early-career Chilean
researchers to choose UK as their preferred research destination,
consolidating the UK's position as one of the leading countries for
attracting global talent.
In addition to the above, the project will also have economic impact.
The oil and gas industry has been a major contributor to the UK
economy for decades. However with North Sea oil fields now very
mature, oilfield revenues face significant decline unless recovery
techniques manage to improve. Improving recovery will also have an
economic benefit as the UK oil industry gradually moves toward
decommissioning: there is a clear economic driver to extract as much
oil as possible from an oil reservoir prior to any decommissioning
operation.
Yet another impact of the project will be social. The oil and gas
industry is one of the biggest employers UK-wide, meaning that many
livelihoods depend on it. This project will provide modelling tools
and associated training for UK oil industry employees, enabling them
to plan and direct improved oil recovery operations, not just in the
UK, but anywhere in the world. This skill set and expertise will then
position the UK as a service provider to the oil and gas sector
globally, helping to create even more UK jobs whilst simultaneously
leading to impact far beyond UK-based extraction operations. Finally,
to ensure that there is a ready supply of trained UK people able to
fill these future UK jobs, we will use public engagement as a tool to
attract young people towards science and engineering disciplines. This
will be achieved with the help of the University of Strathclyde-based
public engagement group ``Really Small Science''.
number of levels.
First of all, the project will generate new knowledge on how foam
injected into an oil and gas reservoir manages to push oil out,
particularly in situations when the direction of the foam flow changes
as a new injection well comes online. Specifically we will develop
models that will allow petroleum engineers to optimise oil recovery
from existing reservoirs, with the models thereby informing optimal
placement of wells. Given that in oil extraction operations, drilling
a well in the wrong place can be a costly mistake, having robust
models of where and when to drill, will be of immense value to the oil
industry.
Although the work is set in the context of oil recovery, the knowledge
that we generate will have wider impact beyond this field. Indeed the
set of mathematical models we need to study arise not just in
petroleum engineering applications but in many other contexts as well,
including suspension mechanics, supersonic flow, spread of epidemics,
pedestrian flow and fire front propagation. The knowledge generated
in the present project will therefore have impact across the wider
applied mathematics community, and even beyond: ability to model
propagation of a bushfire front for instance, is of great importance
in regions affected by drought exacerbated by climate change.
In addition to impacting upon knowledge, the project will also impact
on people. Specifically it will contribute to the pipeline of
talented researchers working in the area of engineering and applied
mathematics. The project will achieve this not only directly (i.e. by
providing the named researcher, Carlos Torres, with postdoctoral
funding) but also indirectly: after completion of the project, Torres
will return to an academic post in his home country (Chile) where he
will be able to encourage a new generation of early-career Chilean
researchers to choose UK as their preferred research destination,
consolidating the UK's position as one of the leading countries for
attracting global talent.
In addition to the above, the project will also have economic impact.
The oil and gas industry has been a major contributor to the UK
economy for decades. However with North Sea oil fields now very
mature, oilfield revenues face significant decline unless recovery
techniques manage to improve. Improving recovery will also have an
economic benefit as the UK oil industry gradually moves toward
decommissioning: there is a clear economic driver to extract as much
oil as possible from an oil reservoir prior to any decommissioning
operation.
Yet another impact of the project will be social. The oil and gas
industry is one of the biggest employers UK-wide, meaning that many
livelihoods depend on it. This project will provide modelling tools
and associated training for UK oil industry employees, enabling them
to plan and direct improved oil recovery operations, not just in the
UK, but anywhere in the world. This skill set and expertise will then
position the UK as a service provider to the oil and gas sector
globally, helping to create even more UK jobs whilst simultaneously
leading to impact far beyond UK-based extraction operations. Finally,
to ensure that there is a ready supply of trained UK people able to
fill these future UK jobs, we will use public engagement as a tool to
attract young people towards science and engineering disciplines. This
will be achieved with the help of the University of Strathclyde-based
public engagement group ``Really Small Science''.
Organisations
Publications
Esmaeili E
(2022)
Squeeze film flow of viscoplastic Bingham fluid between non-parallel plates
in Journal of Non-Newtonian Fluid Mechanics
Grassia P
(2022)
Analysis of a model for surfactant transport around a foam meniscus.
in Proceedings. Mathematical, physical, and engineering sciences
Grassia P
(2023)
A model for foam fractionation with spatially varying bubble size
in Chemical Engineering Science
Grassia P
(2022)
Electro-osmotic and viscous effects upon pressure to drive a droplet through a capillary
in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Grassia P
(2023)
Quasistatic model for foam fractionation
in Chemical Engineering Science
Rajabi H
(2023)
Transport of soluble surfactant on and within a foam film in the context of a foam fractionation process
in Chemical Engineering Science
Rajabi H
(2023)
Transport of convected soluble surfactants on and within the foam film in the context of a foam fractionation process
in Chemical Engineering Science
Description | The award led to a number of publications (as reported within Research Fish). The most important of these in the context of the objectives of the award was C. Torres-Ulloa and P. Grassia. Foam propagation with flow reversal. Transport in Porous Media, 147:629--651, 2023 doi: 10.1007/s11242-023-01925-5 In this publication it was demonstrated (using so called fractional flow theory) that reversed foam flows in porous media did indeed have different mobilities from forward flows. In fact, reversed foam flows have much lower mobility due to selecting a different set of liquid saturations from those selected in forward flow. This is a good outcome for using foam within geological storage applications, since it means that gas injected into a porous medium once foamed is unlikely to leak out of the medium back the way it entered. Nevertheless the publication also revealed a surprising finding. Even though low mobility regions of both forward and reversed foam flows were confined to a small domain of liquid saturations, that small domain of saturations turned out to map to an unexpectedly large domain of physical space. This then opened up new research questions about the premise upon which the proposed research of the award had originally been conceived, namely the premise that foam flows might be simplified through pressure drops being confined to small spatial regions neighbouring the foam front. The actual scenario, in which pressure drops are spread over a large spatial domain, does not immediately invalidate the modelling approach proposed (the so called pressure-driven growth approach). However it does mean that pressure-driven growth can only be used at best to track the location of foam fronts. Reconstruction of pressure fields and liquid saturation fields behind the instantaneous foam front needs additional information to be supplied, for instance information about the past history of the front's trajectory. It currently remains unclear how such reconstructions will perform compared to conventional approaches to modelling foam in porous media (a full multiphase Darcy-type model for pressure fields, for liquid saturation fields and for foam front locations). Another outcome that was useful for the research team was finding out just how widely the topic of the research (foam propagation in porous media) can be utilised. The original proposal tended to focus on one specific application (foam improved oil recovery) but in fact there are many applications across many fields (storage applications, remediation applications, etc.). These are described elsewhere in this report (see the ``Narrative Impact'' section). |
Exploitation Route | Taking the research forward academically relies, as has been mentioned, on answering questions as to how useful the pressure-driven growth model might be even in a scenario in which low mobility regions are spread over a considerable domain in space, not just confined near a foam front. As already alluded to, it will be necessary to attempt to reconstruct pressure fields and liquids saturation fields based on the history of the pressure-driven growth predictions. To address these open questions, the postdoc who had been employed on the grant, Dr Carlos Torres-Ulloa, secured two years of additional funding from a sponsor in his home country Chile. Specifically the funding has come from the Centro de Investigacion, Innovacion y Creacion of the Universidad Catolica de Temuco. The quality of the above mentioned reconstructions will determine the extent to which pressure-driven growth can be used in non-academic settings, e.g. to model foam oil recovery within the energy sector. However it became apparent during the course of the award, that the research was also relevant in various additional processes, including aquifer remediation and soil remediation in the environmental sector. Details can be found under ``Narrative Impact''. |
Sectors | Energy Environment |
Description | The research as proposed envisaged impact in four broad areas: knowledge, people, economy and society. Details of how the findings have been used in each of these broad areas, as well as some of the challenges involved in realising impact, are described below. In terms of knowledge and academic impact, a number of journal publications have been produced (as listed in ResearchFish). In addition, some of the significant academic conference presentations included: P. Grassia and C. Torres-Ulloa. Three bubbles good, two bubbles better. In British Society of Rheology Midwinter Meeting, Durham University, UK, 12th--13th December, 2022 P. Grassia, M. Eneotu, and C. Torres-Ulloa. Foams in porous media great and small. Keynote lecture in 6th InterPore UK Conference, Brunel University, Uxbridge UK, 12th--13th September, 2022. C. Torres-Ulloa and P. Grassia. Foam front propagation in flow reversal. In EUFOAM, Krakow, Poland, 3rd--6th July, 2022 The research proposal as written envisaged much more in the way of conference presentations than actually occurred. However the proposal was submitted to EPSRC prior to any Covid-19 lockdowns occurring, and the award itself began during Covid-19 restrictions. Although we participated in online meetings during the lockdown period, opportunities for travelling to present at conferences or indeed to make in-person visits to other research groups during this time were limited. In terms of developing people, the postdoc employed on the award Dr Carlos Torres-Ulloa was a co-author on the original proposal, and the project certainly helped him to develop his research career with him being an author on half a dozen outputs published during the course of the award (as listed in Research Fish). What is encouraging is that by the end of the project Dr Torres-Ulloa managed to secure follow on funding in a research project that he himself led back in his home country Chile. In terms of economy/economic impact, something that became apparent during the course of the award is that even though the proposed research had first been envisaged as being applicable to foam improved oil recovery, the topic (foam flow in porous media) is also relevant in much broader scenarios and hence in additional economic sectors. For instance, foam in porous media is relevant to sequestration of carbon dioxide (captured CO2 once foamed is less mobile than unfoamed CO2 gas) and also to storing hydrogen in porous media (again foamed H2 is less likely to escape from storage prior to being recovered for use). Aquifer remediation and soil remediation are additional environmentally beneficial applications involving foam in porous media. This then in turn led to additional academic impact with the research group moving into this new research area. These various applications in the respective economic sectors of energy and environment (along with open academic research questions associated with them) were reviewed in one of the publications produced during the course of the award. P. Grassia, H. Rajabi, R. Rosario, and C. Torres-Ulloa. Surfactant transport upon foam films moving through porous media. Colloids and Surfaces A, Physicochemical and Engineering Aspects, 679:132575, 2023 doi: 10.1016/j.colsurfa.2023.132575 One proposed impact (in terms of economy and also developing people within industry) that was not however realised was a training workshop in which delegates from the energy sector could gain hands-on experience with using software that we developed related to pressure-driven growth (and thereby deploy the software in their operations). The reason this workshop did not happen has already been alluded to under the ``Key Findings'' section. We established that an assumption underlying pressure-driven growth (namely that low mobility regions are confined, not just to a small domain in liquid saturation, but also to a small domain in physical space) was not in fact correct. This meant that before a workshop on pressure-driven growth could be delivered, we need first to explore in more detail the extent to which pressure fields and liquid saturation fields could be reconstructed successfully via a pressure-driven growth model. In terms of society/societal impact, one of the planned impacts was undertaking public engagement activities aimed at encouraging schoolchildren into science and engineering careers. Although the Covid-19 pandemic restricted the amount of face-to-face engagement that we could undertake in the early part of the award, later in the lifetime of the award, this became possible again. During 2023 for instance Dr Elaheh Esmaeili, a researcher employed part-time on the project, led one of the sessions at Strathclyde's Young WeirWISE programme. The overall aim of this programme is to encourage secondary school girls to pursue engineering degrees and thereby promote diversity in the engineering profession. The specific engagement sessions that Dr Esmaeili led dealt with environmentally beneficial applications of foam in porous media. We also used online means promote the award and engage more widely. Indeed one of our publications C. Torres-Ulloa and P. Grassia. Viscous froth model applied to multiple topological transformations of bubbles flowing in a channel: Three-bubble case. Proceedings of the Royal Society A, 479:20220785, 2023. doi: 10.1098/rspa.2022.0785 was identified by the publisher as being of special interest, which in turn led to an invitation to record a research seminar for the online seminar platform Cassyni. The seminar recording is available via doi: 10.52843/cassyni.d5twxd |
First Year Of Impact | 2003 |
Sector | Education,Energy,Environment |
Impact Types | Societal Economic |
Description | Young WEIR-WISE: Discovering Engineering with S2 Girls |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | Young Weir-wise is a programme of activities at University of Strathclyde aimed at inspiring S2 (secondary 2) girls to consider a career in engineering. It runs over two days per cohort for two separate cohorts (150 attendees in total). A member of the project team on the current project (a public engagement research assistant) attended the programme, and on one of the days of the programme led activities on behalf of the Department of Chemical and Process Engineering, one of several departments involved within Strathclyde's Faculty of Engineering. |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.strath.ac.uk/engineering/outreach/weir-wise/ |