How can mathematics help your business decisions?
Our approach
Why is our service relevant for you?
Our offer
Success stories
Experienced managers
and engineers in the oil industry all too often see
more junior staff, lost
in the details of their latest big computational
models, failing to analyse properly the key decisions that need
to
be made – “What
recovery mechanism shall we use? How many wells do
we drill? What facilities capacity do we need? How do we operate
the artificial lift system? What do we do if reservoir permeability
is better
than we expect?”
To solve these problems and to derive early
on the insights that would otherwise come from long and expensive
experience, SERAFIM Consultancy uses mathematics and simplified
system models in conjunction with the industry-standard computational
models.
If you want
high-quality reservoir and petroleum engineers with the tools
to see the big picture, contact SERAFIM Consultancy.
Challenging
non-standard problems
SERAFIM Consultancy has a proven record of
accomplishment when it comes to successfully tackling non-standard
problems in Reservoir and Petroleum Engineering. In many cases,
as a result of working on a non-standard problem, we have created
algorithms, based on a set of equations that we derived. Our clients
continue to use our innovative methods and we have implemented
several of our developments in our software packages.
C-Curves, Free Gas:Liquid Ratio, Dual Discount Rate for Project NPV are only
a few examples of our achievements. We believe that our unique set of skills
allow us to reach innovative solutions faster adding excellent value to our
clients’ business.
How can mathematics help your business
decisions?

Our unique set of capabilities and problem solving approach
saves our clients weeks of effort
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When we tackle a problem, we attempt to maximise
the use of the, generally, scarce information available. Be it
production history, petrophysical or geological data, we transform
it into meaningful information by approaching it from different
angles using different tools. For instance, we implement simple
data mining techniques to understand the quality of the data or
the interrelationships that may exist between apparently different
unconnected parameters. We also derive theoretical limits for the
probable variance of the data in order to avoid studying impossible
cases when working on uncertainty issues. We thus uncover otherwise
unobvious interpretations/limitations of the data improving your
decision-making.
Our approach
We believe that our strength resides not only
in the combination of skills and experiences that we have but also
in the way we do things internally and with our clients. We work
with our clients closely to define the problems they attempt to
solve (be it an entire project (field development, acquisition,
reservoir management etc...) or a non-standard problem (modelling
unique reservoir behaviour, solving a complex production allocation
problem, estimating the economic value of heavy oil fields etc).
We then agree with our clients on a specific formulation of the
problem that we model analytically before moving to work that is
more detailed. We also work on maximising the use of the data available
by mining for interrelationships and quality issues. The major
contribution that SERAFIM Consultancy provides to its clients is
the problem specific analytical model that will be used both to
understand the situation better and to assess the detailed work
(like simulations).

Distinctive set of capabilities
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Our work with clients (directly or through
virtual teams), is supported by our capacity to learn and innovate.
We have a strong record of accomplishment of deriving specific
formulations for non-standard problems and the development of cutting
edge algorithms to solve them.
Moreover, we enjoy sharing our knowledge with
our clients and learning from them.
Why is our service relevant for you?
We can add true value to your business when working with you on
technical issues central to your business. We may be helpful if
you are:
- Looking for high quality reservoir and petroleum engineers
capable of using both the industry-standard software and basic
mathematics and engineering reasoning.
- Needing additional resources to carry out in-depth analyses
of the opportunities you come across
- Challenged by non-standard reservoir engineering problems
- Needing a simple yet robust analytical model of the behaviour
of your reservoir to make an immediate decision
- Studying the potential of a field using a limited amount of
information
- Setting up a calculation methodologies for a commercially sensitive
parameter (production allocation, production optimisation, lift
optimisation, specific project assessment measure etc)
- Engaging in R&D projects and wanting an outsider’s
input
Our offer
Our consultancy service can offer support on:
Standard problems
- Project appraisals and economics
- Field development planning
- Reservoir characterisation
- Reservoir modelling and simulation
- Acquisition appraisals
- Reservoir management
- Production optimisation
- Risk analysis
Non-standard problems
- Modelling unique production fluid characteristics
- Modelling unique reservoir behaviours
- Solving complex calculations such as production allocation
- Optimisation of
- Field development
- Pressure networks
- Production
Success stories
Heavy oil field development study
Context: The client
was launching, together with a National Oil Company (NOC), a
joint study of a difficult, heavy oil field. The client needed
the study to show-case its expertise and demonstrate to the NOC
the benefits that might arise if the client were given acreage
to operate. Unfortunately, the work-load on the client’s
existing acreage had just gone up. Where would they find at short
notice highly-expert staff to assist on the project?
SERAFIM Consultancy Contribution: SERAFIM supplied
a reservoir engineer and petrophysicist to be part of the client’s
multi-discipline team and work in conjunction with the client and
NOC reservoir engineers. The SERAFIM engineer helped with log analysis,
well-test analysis, reservoir simulation and training and support
of the NOC engineers.
Benefits: The SERAFIM reservoir engineer helped
resolve the uncertainties about asphaltene behaviour and the discrepancies
between well-test behaviour and laboratory PVT measurements. The
NOC staff expressed themselves as very pleased with the training
and support.
Free gas:liquid Ratio*
Context: our client, then a small producer
with operations in Western Africa needed to model thin oil rim
fields, with extensive gas coning. The bigger fields had reservoir
simulation models, but the smaller and older fields did not. For
investment and planning reasons, our client needed to forecast
overall gas and oil profiles using the basic information on:
- Past production
- Gas coning
- The Geology of the reservoirs
SERAFIM Consultancy contribution: We derived
a new algorithm to forecast associated gas production. The algorithm
was based on the observation that, once the gas cones reach the
production wells, the gas-liquid contact tends to reach an equilibrium
position, with an associated equilibrium free-gas:liquid ratio
that can be calculated from the gas and liquid volumes in place.
The new algorithm was implemented in a software routine as part
of the client’s decline analysis work-flow.
Benefits: The resultant gas production forecasts
have proved robust and suitable for both medium and long-term production
forecasting. The insight into the fundamental mechanisms of oil-rim
gas coning has helped determine the optimal choice of well cut-back
criteria.
*More detailed presentation is to be published
soon in open literature and on our website
C-Curves†
Context: In a combined reservoir/facilities/economics
model of a heavy oil field, decline curves were being used to interpolate
between the results of a small number of simulator runs. However,
neither exponential nor hyperbolic curves gave a good match to
the simulator profiles, whose decline rates diminished with time
and then stabilized.
SERAFIM Consultancy Contribution: The SERAFIM
reservoir engineer derived a mathematical formulation more general
than the hyperbolic curve and successfully used it to match the
simulator profiles.
Benefits: The combined
reservoir/facilities/economics model was successfully calibrated
to the simulator runs and then used for multiple optimisations,
sensitivities and Monte Carlo calculations that would have taken
an impossibly long time to calculate if the simulator had been
directly linked into the combined runs. The client was able to
analyse the full range of field development options, taking into
account the key uncertainties in STOIIP, reservoir quality, well
deliverability and reliability.
† Details in SPE paper 9609
Production Allocation
Context: A major North Sea operator approached us to
solve a production allocation problem. They had four wells producing
to a subsea manifold, which in turn channels the multiphase flow
through a 30km pipeline to a FPSO. The data they had consisted
in downhole gauges readings of THP, THT, BHP and BHT for each well
and the aggregate production measured at the FPSO. In theory, the
data was sufficient to determine the individual well production
rates, but the existing allocation calculation was giving incorrect
results.

Allocation problems usually require strong engineering and
mathematical skills
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SERAFIM Consultancy Contribution: SERAFIM
examined all the aspects of the problem, from the reservoir to
the details of the original tool measurements to the mathematics
of the allocation calculation. The analysis showed that the allocation
calculation was using an algorithm that was mathematically inappropriate
for data with the level of noise seen in the gauge measurements,
and that earlier attempts to solve the problem had been hindered
by errors in data transfer. A software routine was written, implementing
an alternative, more robust allocation calculation and this was
applied to both current and historical production data.
Benefits: The new production allocation resolved a number
of anomalies in apparent reservoir behaviour and has simplified
the reservoir simulation history match, leading to a reservoir
simulator model that can be used with more confidence to commit
to planned new wells. |