■ Geology - p36 ■ Gas - p38 ■ Exploration - p46 ■ Technology - p56
Volume 7 Issue Two 2012
www.oilreviewafrica.com
Africa
Covering Oil, Gas and Hydrocarbon Processing
Europe m10, Ghana CD18000, Kenya Ksh200, Nigeria N330, South Africa R25, UK £7, USA $12
GNPC gears up for
Ghana O&G sector
Determining the
maritime boundaries
Angola’s clean
alternative to flaring
Technology driving
Africa’s LNG
Changing the face of
real-time remote
pressure management
Africa’s subsea market
hots up
Meeting the deepwater
challenge
Vsats - how much
should one pay?
Joe Udofia, MD-CEO of Vandrezzer
Energy Services Limited, Nigeria
See page 6.
Angola...old
challenges
remain
REGULAR FEATURES: ■ News ■ Contracts ■ Events Calendar ■ IT update ■ Company profiles ■ Products & Innovations
Technology
Driven by the need to develop fields in deeper waters, more challenging locations and in
reservoirs of increasing geological complexity, the subsea installation market is expected
to grow at a significant pace over the next few years, with deepwater developments likely
to be a major element of many of the world’s IOC and NOC portfolios.*
The African subsea market continues
to hot up
T
HE LATEST WORLD Deepwater Market
Report from analysts Douglas Westwood
forecasts a 90 per cent growth in
deepwater expenditure between 2012
and 2016 as compared to the previous five-year
period, with a total of US$232bn predicted to be
spent subsea. In addition, Emerson expects the
number of new Christmas Trees coming on stream
each year to increase from about 280 in 2011 to
around 720 by 2016.
As part of the so-called deepwater ‘golden
triangle’ alongside North and South America, Africa
is likely to secure a significant portion of this spend
with the same Douglas Westwood report estimating
that 72 per cent of forecast deepwater spend will
be in Africa and the Americas.
Another report from Quest Offshore Resources
(Subsea Acceleration: Fathoming New
Technologies) forecasts 3,200 new subsea tree
orders between 2011 and 2015 with 60 per cent of
these being in offshore Brazil and Africa. Along with
Brazil and Australia, West Africa remains a key
market for Emerson and we are currently pursuing
80 subsea projects over the next two years.
So in what specific areas is this growth in
subsea installations being seen?
The increasing demand for subsea trees and
associated hardware, such as control modules,
manifolds and umbilicals, is helping drive the need
for many broader solutions – solutions that can
provide operators with more information and
greater control over their subsea operations.
This covers everything from reliable reservoir
and well monitoring in order that production keeps
flowing, through to the avoidance of costly shutdowns resulting from sand, hydrates or an increased
amount of water in the flow lines.
Continued growth of multiphase meters
Take the issue of measuring flow rates in the well
streams and the role of multiphase and wet gas
meters subsea.
Today, there is a definite need for multiphase
flow meters to be installed from field start-up to
efficiently manage the reservoir throughout its
production life, ensure optimal recovery and
maximise output. As of 2010, according to Gioia
Falcone of Texas A&M University and Bob Harrison
from Soluzioni Idrocarburi Srl, there were 3,314
multiphase and wet gas meters installed worldwide
– a number that is likely to double over the next
ten years.
Current Emerson multiphase installations in
Africa include the West Delta Deep Marine (WDDM)
66 Oil Review Africa Issue Two 2012
Emerson's subsea network answers many of operators’ questions relating to subsea operations.
The last few years have seen
a raft of new subsea
challenges
concession offshore Egypt, where 49 Roxar Wetgas
meters have been installed to help the operator
Burullus monitor water production profiles in realtime; the deepwater Akpo field, offshore Nigeria
where Roxar subsea Multiphase meters have been
deployed; and the Kizomba B development, offshore
Angola, where Roxar subsea Multiphase meters and
subsea sensors have been installed for the operator,
Exxon. Through the continuous measurement of the
amount of oil, condensate, gas and water at the
wellheads on the sea bed, Exxon will be able to
determine the optimal production capacity of each
well (thereby avoiding the risk of overproducing the
well), increase flow assurance from the fields and
optimise the production process.
In the WDDM example in Egypt, over just a four
month period, the Wetgas meters were utilised to
avoid several water breakthroughs, identify zones
for water production, and optimise gas production
within acceptable and controlled water rates. By
providing early warnings of the water produced, the
meters have helped Burullus and its partners save
several wells from water breakthrough leading to a
sustainable production strategy moving forward.
For all the benefits of multiphase meters,
however, the last few years have seen a raft of new
subsea challenges that they have to face. This
includes a wider range of process conditions with
more liquid and water present in the flow as well as
deeper wells with higher process pressures and
temperatures; and the growing remoteness of many
subsea fields where costs for subsea interventions
and periodic fluid sampling (PVT) are high.
In addition, there has also been an increase in
the number of subsea tie-backs with
EICDataStream, the global projects database of the
UK trade association, the Energy Industries Council
noting that there are 27 current and future subsea
tie-back projects in Africa. Examples of fields where
subsea tie-backs are in place include the Diega &
Carmen oil fields in Equatorial Guinea; the Foxtrot,
Mahi & Manta gas fields off the Côte D’Ivoire; the
Erha North and Erha South fields, offshore Nigeria;
and the Kizomba development offshore Angola
where Emerson’s Roxar meters are in place.
The risks of longer horizontal production
pipelines and tie-backs is that it takes more time to
detect a water breakthrough in the well, increasing
the need for real-time monitoring to prevent
obstacles to flow assurance, such as hydrates and
water encroachment.
It is therefore vital that today’s subsea multiphase
and wet gas meters come with an extended operating
range, added resilience, and generate ever more
accurate and sensitive measurements of flow rates
and water production profiles.
Emerson’s latest subsea wet gas meter, for
example, is being designed to include new
microwave electronics to provide even more stable
and accurate measurements. The meter will be
Technology
The new Roxar downhole flow sensor system generates multiphase flow measurements from downhole
in the well and deep in the reservoir.
Downhole reservoir
monitoring and hydrate
management are also
crucial to African subsea
operations today.
particularly applicable for new gas finds, such as off
the East African coast where Anadarko and ENI, for
example, are engaging in significant exploration
activities offshore Mozambique.
With the new meter, transmission and
resonance measurement significantly extend the
operating range. The meter also includes a salinity
measurement system which can inform the
reservoir engineer where formation water is
entering the flow as well as also helping the
process engineer when adjusting injection rates of
scale and corrosion inhibitors.
Other developments in Emerson’s multiphase
metering capabilities include a new downhole flow
sensor system which will, for the first time,
generate multiphase flow measurements from
downhole in the well and deep in the reservoir,
leading to increased operator understanding of
reservoir flow and zonal contributions from wells;
and to be launched in early 2013, a subsea version
of Emerson’s third generation multiphase meter.
The new meter version will be two thirds of
the size and half the weight of the current
subsea version without any technology
compromises. Such compactness is crucial, with
many subsea manifolds offshore Africa already
crowded with instrumentation.
pressure and water cut, but also gas fraction, sand
rate and flow velocity.
Deployed in production, injection, or
observation wells, the Roxar Permanent Downhole
Monitoring System (PDMS), for example,
continuously transmits accurate pressure,
temperature and flow rate data from the reservoir in
real time to local or remote well control facilities.
Some of its gauges have been in operation for
decades, requiring minimal maintenance.
In addition, Emerson has recently launched a
new solution that can generate information from
the B annulus within the casing of an oil well –
previously a ‘no go’ area. The new tool is expected
to have a significant impact on both production and
offshore safety, provide early warnings of high
pressures, protecting casing integrity, and
preventing pressure build-up and, in the worst case
scenarios, shallow gas blow outs.
68 Oil Review Africa Issue Two 2012
Transparency & integration
It is this integration of instrumentation which is
central to the increased need for transparency and
better handling of information in Africa’s subsea
field operations.
This is being enhanced through a specialised
Windows-based field monitoring system which
enables E&P operators to observe their fields from
remote facilities.
Known as Roxar Fieldwatch, the system
incorporates a wide range of Emerson’s reservoir
monitoring instrumentation within one single
control system framework, covering everything
from sand monitors and erosion probes through to
downhole pressure and temperature gauges; and
the tracking of well test jobs.
The latest version also comes with new
erosion-combatting capabilities which enable
operators to install virtual erosion sensors within
their production system – particularly to monitor
bends, T-bends and reducers in areas where it’s
difficult to deploy physical sensors. While not as
accurate as real sensors, the virtual erosion
models can calculate important production
information by inputting flow information,
pressure and temperature data.
Maximising asset returns
Success in maximising asset returns in subsea
operations today depends largely on operators’
ability to characterise and understand reservoirs
and generate accurate production information to
guide decision-making.
How are my wells performing? Are there any
conditions that affect my assets and the production
flow? How do I keep my assets working for the full
life of the field with the same efficiency?
Many of these questions are now being
answered. ■
Downhole reservoir monitoring
& hydrate management
Downhole reservoir monitoring and hydrate
management are also crucial to African subsea
operations today.
To this end, Emerson’s Roxar intelligent
measurement devices and sensors are highly robust
and are utilised not only to monitor temperature,
Hydrate build-up, where crystals formed in high
pressure and low temperature gas flows can block
pipelines and interfere with production, are also a
particular risk in deepwater fields today.
The situation can be made even worse,
however, if the wrong amount of hydrate
inhibitors, such as MEG (Monoethylene Glycol), is
injected. We have seen cases, for example, where
up to 20 per cent of the pipeline capacity is
occupied with MEG, due to overdosing.
In response to this need to establish greater
control over the measuring and injection of hydrate
inhibitors, Emerson has developed a compact and
robust subsea retrievable injection valve solution,
which provides operators with precise control over
chemical dosage rates.
The injection valve can also be integrated
with other measurement solutions, such as the
subsea wet gas meter, to increase subsea
production performance. In this case, the wet gas
meter measures the early onset of formationwater production and then the subsea chemical
injection valve ensures that the necessary
preventative is action.
The Roxar subsea Multiphase meters have been
deployed on fields, such as the Akpo field offshore
Nigeria and Kizomba B development offshore Angola.
* By Steve Jennings & Ingar Tyssen, Emerson
Process Management..