Improved geological models aiding hydrocarbon reservoir development
Submitting Institutions
University College London,
Birkbeck CollegeUnit of Assessment
Earth Systems and Environmental SciencesSummary Impact Type
TechnologicalResearch Subject Area(s)
Earth Sciences: Geochemistry, Geology, Geophysics
Summary of the impact
UCL's Deep-Water Research Group (DWRG) creates knowledge transfer between
research and the hydrocarbon industry. Oil companies use the DWRG's
research results to generate improved in-house computer-generated
hydrocarbon reservoir models, allowing them to manage, develop and value
their reservoirs better. The same companies also use the research to run
training courses for employees, including reservoir engineers and
managers, leading to improved understanding and more informed
decision-making about the management of hydrocarbon reservoirs. Improved
management and development of reservoirs ultimately leads to oil companies
being able to extract a greater amount of oil.
Underpinning research
The Ainsa sedimentary basin in the Spanish Pyrenees contains cumulatively
around 4 kilometres of exhumed conglomerates, sandstones and shales that
accumulated in a deep-marine seaway in the order of ~500 metres water
depth over 10 million years in the Middle Eocene time period (~50-40 Ma).
The basin formed part of a connected seaway along the length of what are
now the foothills of the Pyrenean mountain belt. It was around 150
kilometres in length and was connected to a palaeo Bay of Biscay. The
clastic sediments that accumulated in the Ainsa basin (and the
time-equivalent and connected Jaca and Pamplona deep-marine basins to the
east) formed submarine fans and associated deposits that were supplied
mainly from rivers and deltas of the rising Pyrenean orogen to the north
and east. These sediments provide arguably the most complete and linked
ancient sedimentary system anywhere in Europe, and indeed globally. As
such, these sediments are of considerable interest to the hydrocarbon
industry as analogue models for many sites of hydrocarbon exploration and
production worldwide, and for training technical staff (geologists,
geophysicists, palaeontologists, reservoir engineers).
UCL's DWRG, based in the Department of Earth Sciences and led by Kevin
Pickering (Professor 1993-present), managed an integrated
outcrop-subsurface study of the deep-marine sandy submarine-fan deposits
in the Ainsa basin (Ainsa Project drilling phase 1997-1999). This
groundbreaking project — the only integrated outcrop-subsurface study of a
coarse-grained deep-marine system worldwide to date — was funded by a
consortium of oil companies under the auspices of the Norwegian Petroleum
Directorate (NPD), including Conoco, BP, ExxonMobil, NorskHydro-Statoil,
TotalFinaElf and Phillips Petroleum. With funding from other oil
companies, the Ainsa Project has continued since the drilling phase until
the present time. Research conducted as part of the Ainsa Project has
included onshore drilling and coring, detailed sedimentary core logging,
seismic acquisition, wireline logging, micropalaeontology and sedimentary
petrography.
As part of the post-drilling phase of the Ainsa Project, the UCL DWRG has
been and continues to be involved in several industry-sponsored
field-based sedimentological and stratigraphic studies:
(i) Investigations of the architecture of the sandy systems in the Ainsa
basin, including their thickness, geometry, and lateral and vertical
connectivity [1]. Research results included the production of the first
detailed geological map for the aerial distribution of the sandy systems,
prior to which only sketchy maps were available. This project was
sponsored by Shell UK (2002-2010) and ExxonMobil (2007-2012).
(ii) A study of the Guaso system in the Ainsa basin, which found it to be
a structurally confined, low-gradient, mainly fine-grained, deep-water
system for which, prior to this study, only a very few and poorly
documented case studies existed [2]. This work underpins interpretations
of the Buzzard Field, northern North Sea, which consists of stacked
sandstone reservoirs in a shelf-edge-delta-supplied basin. It was
initially sponsored by Shell UK (2005-2010). In 2005, the UCL DWRG was
also involved in an evaluation of the reservoir sandstones, including
thin-section work, when the Buzzard Field was first drilled by PanCanadian
(now Nexen Petroleum), which in turn led to Nexen Petroleum funding
present research by the UCL DWRG.
(iii) Studies of trace fossils in the Ainsa basin and their use in
environmental interpretation, something that is invaluable to oil
companies looking at limited core material [3, 4]. This work showed that
trace fossils are powerful indicators of submarine-fan and related
environments. The project was sponsored by BP (2002-2007).
(iv) Study and characterisation of the stratigraphic significance of
mass-transport deposits/complexes (MTDs/MTCs) in the Ainsa basin [5, 6].
Such processes and their deposits can cut out reservoir sandstones and
provide seals to any hydrocarbon-bearing reservoir sandstones, and their
study is therefore of interest to the hydrocarbon industry. Most recently,
this work was sponsored by Nexen Petroleum (2010-2014) [5].
References to the research
[1] Deconvolving tectono-climatic signals in deep-marine siliciclastics,
Eocene Ainsa basin, Spanish Pyrenees: Seesaw tectonics versus eustasy, K.
T. Pickering and N. J. Bayliss, Geology, 37, 203-206 (2009) doi:10/d6zqfs
[2] End-signature of deep-marine basin-fill, as a structurally confined
low-gradient clastic system: the Middle Eocene Guaso system, South-central
Spanish Pyrenees, C. Sutcliffe and K. T. Pickering, Sedimentology,
56, 1670-1689 (2009) doi:10/ds2vsc
[3] Trace fossils as diagnostic indicators of deep-marine environments,
Middle Eocene Ainsa-Jaca basin, Spanish Pyrenees, T. G. Heard and K. T.
Pickering, Sedimentology, 55, 809-844 (2008) doi:10/fn7rhc
[4] Milankovitch forcing of bioturbation intensity in deep-marine
thin-bedded siliciclastic turbidites, T. G. Heard, K. T. Pickering and S.
A. Robinson, Earth & Planetary Science Letters, 272, 130-138
(2008) doi:10/cf5wtp
[5] Channel-like features created by erosive submarine debris flows:
Field evidence from the Middle Eocene Ainsa Basin, Spanish Pyrenees, N.
Dakin, K. T. Pickering, D. Mohrig and N. J. Bayliss, Marine and
Petroleum Geology, 41, 62-71 (2013) doi:10/n4z
[6] Mass-transport complexes (MTCs) and tectonic control on confined
basin-floor submarine fans, Middle Eocene, south Spanish Pyrenees, K. T.
Pickering and J. Corregidor, Journal of Sedimentary Research, 75,
761-783 (2005) doi:10/bx9rdt
References [1], [6] and [5] best indicate the quality of the
underpinning research.
Research grants: Between 1994 and 2010, the group received
£850,000 from various funders, including Exxon-Mobil, Shell (UK), British
Petroleum, BP-Amoco, Chevron, Conoco, Elf, Mobil, Phillips Petroleum,
Statoil and Nexen Petroleum UK.
Details of the impact
The Ainsa basin is of considerable interest to the hydrocarbon industry
because it is an analogue for producing oilfields in deep-marine sandstone
reservoirs in hydrocarbon provinces worldwide.
The hydrocarbon companies that participated in the Ainsa Project have
been impacted upon by the UCL DWRG's research in three ways between 1
January 2008 and 31 July 2013:
1) UCL research results have been used by oil companies including
Chevron, Nexen Petroleum UK, ExxonMobil and BP to create improved
in-house computer-generated hydrocarbon reservoir models aimed at
helping with reservoir characterisation and simulation. These improved
models allow the companies to manage and develop their reservoirs better,
leading to improved company performance.
UCL Ainsa Project results provided hard data on likely reservoir
continuity, porosity-permeability, vertical and lateral pathways and
baffles to fluid flow, which the participating oil companies use to
explore and define levels of uncertainty in their reservoirs. This, in
turn, allows them to value their assets and projects better (e.g.
calculate volumes of recoverable hydrocarbons), leading to more informed
business and investment decisions.
The Head of Stratigraphy at BP noted that the UCL outcrop studies provide
the company with data and ideas at a sub-seismic scale, and are therefore
critical in their development of a range of alternative in-house models
for producing oilfields. He said: "The detailed studies and publication of
the work is one of the key elements in allowing us to understand and plan
the development of our reservoirs" [A]. The underpinning research is used
for the same purpose at ExxonMobil; their Senior Technical Consultant for
Hydrocarbon Systems said: "deep-water systems are important reservoirs for
our company and research like yours help us explore and develop these
resources more effectively" [B].
Nexen Petroleum UK benefits from the research in the same way. Their Lead
Geologist for the Buzzard Field said: "The real value in Kevin Pickering's
work and on-going research to Nexen is in the manner we create and
populate our reservoir models. His and his student's Ainsa Basin research
provides hard data that we use to define certain levels of uncertainty in
our reservoirs. This, in turn, allows us to better value our assets and
projects, leading to more informed business and investment decisions" [C].
Similarly, one of Chevron's Research Geologists said: "Deep-water
reservoirs are extremely important for Chevron's exploration and
production, and understanding of the geology is fundamental to their
success. Quality outcrop field work, such as is provided by the research
group at UCL, is required to provide analogue models, test predictive
stratigraphic concepts, and provide key data on sub-seismic heterogeneity
that impacts fluid flow in these reservoirs. The research undertaken by
UCL in the Ainsa Basin, and the group's publications have greatly assisted
Chevron in this effort" [D].
An example of a hydrocarbon reservoir that has been impacted upon by the
UCL DWRG research results is the Buzzard Field in the northern North Sea,
which is principally operated by Nexen Petroleum UK [C]. This asset is in
its early field life, producing about 200,000 barrels per day (May 2013),
and holds enough crude oil to deliver potentially about 10% of the UK's
annual forecast oil demand. Reservoir complexity and potential reservoir
variability away from well control remain key issues on Buzzard,
accounting for significant volumetric uncertainty and representing the
primary risk for new drilling opportunities. The new model for the spatial
variation of sedimentary lithofacies within reservoir intervals in the
Ainsa basin, developed by the DWRG, has directly impacted upon predictions
of spatial variation in primary sandstone reservoir quality in the Buzzard
Field. Subsequent drilling has corroborated the revised depositional
framework in the reservoir intervals. Revisions to the existing
lithostratigraphic correlation scheme were therefore made and incorporated
into Nexen's subsequent reservoir model updates for the Buzzard oilfield
[C].
2) UCL Ainsa Project research results are used to run in-house
training courses at hydrocarbon companies for geologists,
geophysicists, reservoir engineers and managers. This training improves
understanding amongst company employees and results in them being able to
make more informed decisions throughout their careers about how to manage
their reservoirs, leading to the companies being able to extract more oil
from reservoirs and making more money. The four companies mentioned below
ran at least one in-house training course per year during the REF impact
period.
At Nexen Petroleum UK, "staff are encouraged to participate in
field-courses to the Ainsa Basin, where UCL's work including the UCL-based
Ainsa Drilling project are discussed as it provides a unique dataset
allowing workers to compare 1D well data with 2D and near 3D outcrops"
[C]. A letter from their Lead Geologist for the Buzzard Field says: "I'm
sure anyone who has utilized this data has learnt valuable lessons in
subsurface uncertainty" [C].
Over 500 BP subsurface professionals from around the globe have visited
the Ainsa basin over the last 15 years to take part in training courses
underpinned by the UCL research and have "directly benefited from the UCL
studies" [A]. The Head of Stratigraphy noted that because of UCL's "superb
dataset" on the outcrops in the Ainsa basin, "these outcrops provide
excellent teaching tools, and within BP form the backdrop for regular
deepwater exploration and production courses and an annual reservoir
modelling course" [A].
Chevron also runs a training course in the Ainsa basin, and "has made
extensive use of the research products of the UCL group" [D]. Their
Research Geologist said: "the core and wire-line log data collected from
behind the outcrop provides a unique teaching aid which can be used to
relate subsurface data and well-correlation principles to outcrop
observations" [D]. Similarly, ExxonMobil's Senior Technical Consultant
noted: "We have an intense training effort in Ainsa and the materials and
learnings generated by this program [the Ainsa Project] are a key
component of our training" [B].
3) Hydrocarbon companies benefit from the employment of skilled
research students from the DWRG. Chevron has employed three Ph.D.
students from the DWRG (two in the REF impact period), and is benefiting
from the skills acquired by these employees whilst conducting the
underpinning research [D]. Ph.D. students from the DWRG have also been
employed by ExxonMobil in 2010 [B] and Nexen Petroleum has created
internships in 2012 and 2013 for two of the DWRG's current Ph.D. students
[C].
Sources to corroborate the impact
[A] Supporting statement from Senior Technical Consultant (Hydrocarbon
Systems), ExxonMobil — corroborates the impact on reservoir modelling and
training at ExxonMobil. Also corroborates the employment by ExxonMobil of
DWRG Ph.D. students. Available on request.
[B] Supporting statement from Head of Stratigraphy, BP — corroborates the
impact on reservoir modelling and training at BP. Available on request.
[C] Supporting statement from Lead Geologist: Buzzard Field, Nexen
Petroleum UK — corroborates the impact on training and reservoir modelling
at Nexen Petroleum UK, including modelling of the Buzzard Field reservoir.
Also corroborates the creation of internships at Nexen for DWRG Ph.D.
students. Available on request.
[D] Supporting statement from Research Geologist (Deep Water Research
Group), Chevron Energy Technology Company — corroborates the impact on
reservoir modelling and training at Chevron. Also corroborates the
employment by Chevron of DWRG Ph.D. students. Available on request.