Michael Aryeetey, Lead Geoscientist at GNPC spoke at the Oil & Gas Event June 2013

1. Unlocking the Hydrocarbon
Potential of the Ultra Deepwater
Basins Offshore Ghana
Workshop – Ballroom 2
June 4, 2013; 9:00am
By
Michael N. A. Aryeetey
Lead Geoscientist, GNPC

2. Presentation Outline
• Introduction – GNPC
• Deepwater /Ultradeepwater Exploration Worldwide
• Deepwater /Ultradeepwater Exploration-West African Margin
• Sedimentary Basins in Ghana
• Deep & Ultra Deepwater Data Coverage
• Deepwater Exploration offshore Ghana
• Deepwater Exploration – Tano Basin
• Deepwater Exploration – Keta Basin
• Current Exploration Opportunities
• The Petroleum System
• The Processes & Schedules
• Conclusions

3. Ghana National Petroleum Corp: GNPC
• National Oil Company established in 1983; and given
legal backing by two main statutes i.e. PNDC Laws 64 and
84
• Vision: To be a leading global oil and gas company whose
operations have a profound impact on the quality of life of
the people of Ghana.
• Mandate:
1. To accelerate the promotion of petroleum exploration
activities to ensure early commercial discovery and
production
2. To undertake the appraisal of existing petroleum
discoveries to ensure production to meet national
requirements
3. To ensure that Ghana obtains the greatest possible
benefits from the development of its petroleum resources
4. To obtain the effective transfer to Ghana of appropriate
technology relating to petroleum operations
5. To ensure the training of citizens of Ghana and the
development of national capabilities in all
aspects of petroleum operations and;
6. To ensure that petroleum operations are conducted in
such a manner as to prevent adverse effects on the
environment, resources and people of Ghana.
seismic
Drilling Rig
Oil Tanker
Skill Transfer
Production Platform
3

4. Deepwater Fields Around the World
4

5. Deepwater Exploration Worldwide
• Over the past 20 years, understanding of deep-water depositional
systems has progressed rapidly, while major technological advances
have pushed the frontier for exploration and development of deep-
water fields further offshore
• Reservoirs deposited in deep water occur worldwide in a variety of
tectonic settings, but are particularly common in rift and passive-
margin basins.
• The total number of deep-water fields so far discovered throughout
the world number between 400/500
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6. 6
Deepwater Exploration & Production Worldwide

7. Deepwater Exploration & Production Worldwide
Source: Pettingill (1999)
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8. Deepwater Exploration Successes
Worldwide
• Successful exploration in the Miocene of Nigeria, Angola and Brazil
• Significant success in the Upper Cretaceous in Ghana, Equatorial
Guinea, Liberia, Sierra Leone, Angola etc.
• The Upper Cretaceous-Lower Paleocene successes in the North Sea
• Growing excitement generated by the Agbami giant in Nigeria, La Ceiba
Field in Rio Muni, Jubilee & TEN Fields in Ghana; more along the West
African Margin
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9. Deepwater Exploration-West African Margin
Source: Offshore Magazine 2011
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10. Why is the West African deepwater
so prolific?
Simplicity of the play elements which include:
1. Regional development of abundance of rich oil prone source
rocks
2. Frequent presence of thick clean sands
3. Young structuring
4. On-going hydrocarbon generation
Oil is invariably generated wherever there is sufficient
sedimentary loading for maturity
This region now represents one of the most exciting frontier
exploration provinces in the world!
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11. Prospectivity of the West African Margin
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Country Discovery Operator
Sierra Leone Mercuy Anadarko
Jupiter Anadarko
Cote d’Ivoire
Espoir CNR International
Lion CNR International
Baobab CNR International
Ghana
Mahogany Tullow Oil
Odum Kosmos
Ebony Tullow/Interoil
Mahagany Deep Kosmos
Tweneboa Tullow Oil
Enyenra (Owo) Tullow Oil
Teak Kosmos
Sankofa/GyeNyame ENI/Vitol
Dzata Vanco/Lukoil
Banda Kosmos
Paradise Hess
Akasa-1 Kosmos
Ntomme Tullow
Nigeria Udele-3 Sinopec
Pegi ExxonMobil
Agge-3B.T1 Conoil
Cameroun Sapele-1 Bowleven
Gabon Maroc-Nord (OMOC-N) Maurel & Prom
SE Etame-1 Valco Energy
Angola
Castanha Plus Petrol
Nzanza ENI
Cinguvu ENI
Begonia Total
Cabaca South East ENI
Mpungi ENI
Canna-1 Total

12. Sedimentary Basins - Ghana
Basin Age of Sediments Total Size
Tano-Cape Three
Points
Cretaceous
60,000 sq. km
(up to 3,000m
WD)
Central (Saltpond) Paleozoic
Accra-Keta Cretaceous/
Paleozoic
Onshore Voltaian Precambrian-
Paleozoic
103,600 sq. km
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13. Geological Setting
13
Basin development related to the opening and spreading of the Equatorial Atlantic Ocean and
divergence of the African and South American plates.
The basins are wrench-modified with the deepwater part dominated by Upper Cretaceous
slope and basin floor fans, channel systems and other stratigraphic traps; and Lower
Cretaceous tilted and rotated fault blocks (rift section).

14. Ultra-Deepwater Exploration offshore Ghana
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GHANA
OFFSHORE 2D & 3D SEISMIC COVERAGE

15. The “New Golden Triangle”
15
Ghana

16. Deepwater Fields Offshore Ghana
Cob &
Almond
Pecan
&PN-1
Hickory North
& Paradise
TEN
FIELDS
JUBILEE
FIELDS
SANKOFA –
GYE NYAME
FIELDS
MAHOGANY
TEAK AKASA
FIELDS
DWTCTP HESS
DISCOVERIES DZATA FIELD

17. Current Opportunities – Tano Deep/Ultra
Deepwater
Deep/Ultra Deepwater
THE DEEPWATER TANO BASIN
Cretaceous basin located in the transform margin of West
Africa. Basin development as a result of rifting and drifting of
the Atlantic margin.
Thick Upper Cretaceous-Tertiary section overly a rift section.
The drift section is dominated by slope and basin floor fans,
channel systems and other stratigraphic traps.
The main source rock are the Turonian-Cenomanian section
and the Albian shales.
The thick drift section provide enough overburden to mature
the source rock and the same time serve as seals for the
stratigraphic play types.
This is a PROLIFIC deepwater basin that plays host to
numerous oil, gas, and condensate discoveries; eg. Jubilee
(Mahogany), Tweneboa, Enyenra, Ntomme, Akasa,
Paradise, Sankofa and Dzata.

18. Ultra Deepwater Tano
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• Located in the prolific offshore Tano basin,
in close proximity to the Jubilee Field.
• Water Depth: 2000 - 3,500 m
• Blocks in Basin play host to several
significant oil, gas and condensate
discoveries including the Tweneboa-
Enyenra-Ntomme (TEN) - Tullow; Jubilee
Field-(Tullow & Co), Mahogany-Teak-Akasa
(MTA) - Kosmos; Paradise (Hess); Dzata
(Lukoil/Vanco);
• High quality 2D and 3D seismic data
• Proven Petroleum System
• Numerous unexplored Cretaceous Play
Types

19. Volta River & Sediment Deposition
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20. Deepwater Exploration – Keta Basin
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Basin 2D
seismic
Data
km
3D
Seismic
Data
Sq km
Deepwater
Wells
drilled
Accra Keta
Basin
12,963 2,737 2
Tarpon Well (Devon)
• The Tarpon well was drilled in 2003 to test a series
of Miocene fans on the eastern flank of the Keta
Arch
• The well proved excellent Miocene reservoir, (246
ft. net sand, av. 31% porosity), had trace amounts
of hydrocarbons based on fluid inclusion data.
• The primary reason for failure was the lack of a
robust migration pathway from the Upper
Cretaceous hydrocarbon system into the Tertiary
section.
Cuda Well (Afren)
• Afren drilled the Cuda exploratory well in December
2008 to a depth of 12,425 feet.
• The contractor had to abandon the operation after
encountering excessive high pressure which posed
great danger to life and property.
• Thus, they could not reach the obligated target and
depth
Basin Play Type Drilling Density
Accra Keta
(deepwater)
Stratigraphic 1 well/2000 sq
km

21. Current Opportunities – Ultra Deep Keta Basin
Deep/Ultra Deepwater
Favorable Conditions
•The Volta River creates a unique depositional system along the transform
margin of West Africa in Eastern Ghana that is similar to the Rio Muni Basin
in Equatorial Guinea.
•A tremendous volume of Upper Cretaceous sands were deposited and
excellent reservoir quality Eocene and Miocene sands were encountered in
the two shelfal wells.
•Large volumes of Upper Cretaceous sands were deposited in deep water
fans across the growing structures on the Keta Arch.
•There is enough overburden to mature the rich Turonian source; It is in the oil
generation window.
• The Volta River provides 10000 ft thickness Mid-Miocene to Pliocene
sediments, that caused late phase of oil generation and migration beginning
around 5 million years ago through to today.
•The hydrocarbon migration on the Keta Arch is further supported by
numerous hydrocarbon flags in the shallow section.
•Oil and gas seeps and chemosynthetic communities were observed in piston
cores. A large persistent oil slick is identified on satellite images of various
vintages.

22. Accra-Keta Basin
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Dipline
Strike Line
PINCH-OUT OF DRIFT
SEDIMENTS
ROTATED FAULT BLOCKS – RIFT
SEDIMENTS

23. Offshore Activity Map
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24. Challenges
It relate to all areas of operations including but not limited
to:
• Seismic acquisition,
• Drilling operations,
• Completion operations,
• Subsea operations, production operations,
• Logistics support;
• High Pressures (>10,000psi) & Temperatures (>200°C): HPHT
• Deep and tight Reservoirs (<10mD)
• Flow Assurance Issues

25. Others Have Braced The Storm
• This challenge has seen an exploration well being drilled in over
10,000 ft [3048m] of water and another being drilled in 3,100m in
India
• A subsea production well in the GoM being completed in marginally
less than 10,000ft [3048m] of water.
• It is anticipated that being able to commercially develop resources in
such water depths will be fundamental to the continued long term
success of ultra deepwater exploration in the world’s major producing
basins.
• From a worldwide perspective deepwater developments will account
for approximately 25% of offshore oil production by 2015, compared
to just 9% at present.
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26. The Processes & Schedules
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Dataroom
access and
submission of
proposal to
GNPC
GNPC
Evaluation of all
proposals
GNPC invitation
to and
negotiations with
preferred partner
GNPC and
Partner meets
MOE to discuss
PA
PA approval and
ratification
JOINT VENTURE MODEL
G&G Data
Review @
GNPC
Application
submission to
MOE with US
$10,000
Application
Evaluation by
MOE & GNPC/
PC
Expression of
Interest to MOE
& GNPC
Recommendation
by GNPC Board to
MOE:
Decline /
Invitation for
Negotiations
Negotiation
Team
Constituted by
Minister
Negotiated
Draft PA
initialed &
submitted to
Minister
MOE submits
InitialedPA to Cabinet
for Approval
GNPC Meets Select
Committee on Energy
from Parliament for any
clarification
After Approval, then
to Parliament for
consideration, and
ratification.
PA Ratified;
Company
commences
operations
NORMAL APPLICATION
PROCESS

27. GNPC’s Strategy
• The strategy for attaining this vision incorporates a
preferred alliance model (JOC/JV) with large to medium
size independent companies
• With a Partner who will commit to developing independent
operating capability of GNPC in the medium to long term
and/or transfer of operatorship
• It will also involve participation in equity investment
through innovative risk sharing in alignment with the
objectives of the Corporation.
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28. Conclusions
• The industry is in the busiest period in its recent history
and as we continue to pursue prospects in deeper water
depths and more challenging reservoirs
• The need for technology development and equipment
qualification to meet the corresponding technical
challenges for project development are becoming much
greater.