Memorandum: scope of services to be provided

Transcription

Memorandum: scope of services to be provided
Memorandum: scope of services to be provided
Attachment to Expression of Interest document nr. GR/BOST/TS/0001/2015
Natural Gas Landscape in Ghana
Significant offshore gas reserves have been identified in the western region of Ghana: the Jubilee
field with associated gas reserves estimated at 335 billion cubic feet (bcf), the TEN1 fields with
associated gas reserve of 353 bcf, and the Sankofa field with non-associated gas reserves of
1,168 bcf. These fields are positioned approximately 75km south-southeast of the Ghana-Ivory Coast
border, and 132km southwest of the city of Takoradi. Infrastructure has been built to flow gas from
the Jubilee field for domestic use and allow duel fuel power generators at Aboadze, near Takoradi,
to be switched to natural gas. These power generation plants, owned by the Volta River Authority
(VRA), are currently being run on liquid fuels, at much higher cost than gas-fired generation.
The recently built gas infrastructure includes a 59km offshore pipeline to deliver the gas from the
FPSO stationed at the offshore field, a gas processing plant (GPP) near Atuabo, and a 111km
(diameter 508 mm) onshore pipeline to deliver gas from the GPP to the power generators. The
pipeline transmission system consists of an initiating station (Atuabo Initiating Station, which is
outside the O&M scope for the pipeline), a gas distribution station (Esiama Distribution System), two
block valve stations and one terminating station (Takoradi Regulating and Metering Station). This
infrastructure was built by Sinopec International Petroleum Service Company (Sinopec) under EPC
contract with Ghana National Gas Company (GNGC), and in December 2014, the commissioning of
this infrastructure was nearing completion. Following commissioning, gas is anticipated to exit the
GPP at a rate of ~120 mmscfd, ramping up to a maximum GPP capacity of 700 mmscfd in a future
phase.
BOST as the NGTU
Bulk Oil Storage and Transportation Company Ltd (BOST) is the sole holder of the Natural Gas
Transmission Utility (NGTU) licence, having been issued this mandate by the Ghana Energy
Commission on December 11, 2012 under the provisions of the Energy Commission Act of 1997, Act
541. Under the NGTU licence, BOST is responsible to install, operate and maintain the onshore
transmission network. The existing 111km onshore pipeline between Atuabo and Aboadze falls
under this remit. BOST will commence active duty holdership and take over the operations and
maintenance of this pipeline in Q4 2015. However, BOST does currently not have the required
capabilities to execute operations and maintenance services for a gas transmission pipeline.
Further, over the next decade, BOST intends to build out an entire 1,200km transmission network.
Aligned with Ghana’s national agenda, the first phase of this build out (the Western roll-out) will be
approximately 750km of pipeline from Esiama via Kumasi to Buipe (fully or partly), supporting
development in the north of Ghana and to provide power for clinker production. The remaining
build out (the Eastern roll-out – commencing in 2018) will be approximately 450km to meet demand
in Accra and Tema.
In order for BOST to fulfil its mandate as the NGTU, BOST is now seeking expressions of interest for
the provision of Front End Engineering Design (FEED) services for the ~750km Western roll-out.
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The TEN group includes one gas condensate field (Tweneboa) and two oil fields (Enyenra and Ntomme).
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Front End Engineering Design
FEED services are being sought for ~750km of buried transmission pipeline build out. This Western
roll-out is the first phase of a 1,200km network, and is consistent with Ghana’s national agenda to
support development in the North of Ghana and to provide power for clinker production. Figure 1
indicates the location of the existing pipeline, the Western roll-out (within the scope of this
expression of interest) and the planned Eastern roll-out (outside the scope of this Expression of
Interest).
Figure 1: Ghana Planned Gas Transmission Network
The intention of the FEED contract will be to refine cost estimates, evaluate potential risks and
define a detailed scope for the engineering, procurement and construction (EPC) phase of the
transmission network’s Western roll-out. The successful FEED contractor will work closely with BOST
to adequately define the project requirements and provide a foundation in preparation for
tendering the EPC contract for the pipeline. In conjunction with BOST, the FEED contractor will come
up with a realistic (±10%) estimate of the project cost and duration.
The FEED services required from the successful contractor include, but are not limited to:
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Route selection, with considerations such as crossings and obstructions, rights of way and
land acquisition, and environment and safety.
Pipeline calculations, including line pipe properties, operating conditions, capacity design
for optimal flow rate, pressure containment mechanical calculations, corrosion control and
external load/pressure assessments.
Key material selection, including selection criteria, coatings and corrosions assessment,
material qualification, and material standards and specifications.
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In addition, the successful FEED contractor would be asked to contribute to the development of
Ghana-wide technical standards and specifications to ensure consistent design, build and operations
of the entire transmission network.
To guide any potential FEED contractors interested in responding to this Expression of Interest,
technical details that would guide the nature and complexity of the FEED work are included below.
Supply and Demand Scenarios
The planned Ghana transmission network roll-out has been based on the supply and demand
scenarios put forth in Ghana’s Gas Master Plan, a draft of which is available from Ghana Ministry of
Energy. The Gas Master Plan models various scenarios – low, base and high – to enable a demand
forecast to be generated. Ghana’s predicted total demand under the base demand scenario will
increase from 200 mmcfd in 2015, to 470 mmcfd in 2025, then 932 mmcfd in 2035. All three demand
scenarios are depicted in Figure 2. The successful FEED contractor will be required to translate
various supply and demand scenarios into a pipeline design that most efficiently meets long-term
transport capacity requirements.
Figure 2: Ghana Predicted Total Demand Profile
Ghana Typical Terrain
The proposed pipeline route would pass through various geographical and ecological zones that can
broadly be classified as low plains or round and featureless hills. The vegetation includes agricultural
plantations such as palm and rubber, forest and degraded forest. In general, the majority of the
pipeline route would be considered favourable for cultivation, and thus should not present too many
complications during pipeline construction. The geotechnical situation in Ghana is also considered
suitable for buried pipeline construction.
--BOST reserves the right not to proceed with the project or to change the configuration of the
project, to extend the time table reflected in the Data Sheet or to change the process or procedure
to be applied. It also reserves the right to decline to discuss the matter further with any party
expressing interest.
No reimbursement of cost of any type will be paid to persons or entities expressing interest in
response to this document.
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