Environmental Statement - Maersk Oil

Balloch Field Development Environmental Statement
Non‐Technical Summary
NON‐TECHNICAL SUMMARY
The Balloch field is located in Block 15/20a of the Central North Sea (CNS) in a water depth of
approximately 140 m. The field lies approximately 225 km north‐east of Aberdeen and 36 km west of
the UK/Norwegian median line. Maersk Oil UK Ltd (hereafter referred to as Maersk Oil) propose to
develop the Balloch field as a subsea tieback to the existing Global Producer III (GPIII) Floating
Production, Storage and Offloading facility (FPSO). The proposed field development will consist of the
drilling of an initial appraisal well, from which a sidetrack production well will be drilled. Depending
on the success of the first production well, up to two additional production wells will be drilled.
The wells will be tied back to the GPIII FPSO, which currently handles production from the Donan and
Lochranza fields. Balloch fluids will be commingled with the Donan and Lochranza hydrocarbons and
will undergo processing on the GPIII through existing topsides equipment. Oil will be exported to
shore by tanker and gas will be exported via the North Sea Producer (NSP) FPSO to the Frigg Pipeline.
The Balloch production will be managed such that coincident condensate volumes remain within the
safe operating limits of the GPIII topside processing facilities.
GPIII operations continually monitor export specifications and, as the gas production declines and
richer fluids are processed through GPIII, Maersk Oil will continue to optimise operations. When the
export route is unavailable, the gas will be injected per the recent Donan/Lochranza Field
Development Plan (FDP) amendment. It should be noted that, due to impending fuel gas deficiency, a
project has been initiated by the area operators to change the export line duty to a gas import line
circa 2014. Introduction of Balloch fluids and the implications of increased condensate loading will be
incorporated into this consideration and, as part of the GPIII production strategy, mitigations have
been identified and will be implemented to address the changing fluid composition and production
profiles across the facility.
The development comprises the installation of subsea tieback infrastructure to transport the Balloch
reservoir fluids to the GPIII FPSO. GPIII is currently operated via condensate recirculation; the Balloch
field development will be processed within the existing processing train. Condensate accumulates
within the knock out drums in the High Pressure (HP) and Low Pressure (LP) compression trains and is
routed back to the first stage separator; condensate is cycled until it reaches equilibrium between the
oil and the gas export streams. This is a recognised processing constraint and the base production is
managed to alleviate and manage this. Recent peak liquid throughput has been in the region of
35,000 bbl/d from the L3Z well, which has a richer composition than the previous GPIII fluids. This has
been comfortably handled within the GPIII processing capacity.
Post Balloch first oil, condensate re‐circulation will continue. Control of the GPIII base production will
allow well management to optimise overall GPIII production.
However, it is recognised that Balloch is under‐appraised and there is potential for the high case
profile to be realised. It is predicted that this could exceed current condensate handling capacity.
GPIII operation strategy will address this risk and, as part of the ongoing topside processing
optimisation, mitigations have been identified and will be implemented as necessary. It is accepted
that, as wells decline and richer wells are brought on stream, the production profiles and
compositions will vary during continued GPIII operation and will be addressed throughout the Balloch
field life. Any modifications put in place will recognise this and include sufficient flexibility to address
future gas and liquid handling.
This document provides details of the Environmental Impact Assessment (EIA) that has been
undertaken to support Maersk Oil’s application for consent to undertake the project. This process
includes a period of public consultation followed by a comprehensive review by various bodies
including the Department of Energy and Climate Change (DECC), Marine Scotland, the Joint Nature
Conservation Committee (JNCC) and the Scottish Fisheries Federation.
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