Captain is in the Outer Moray Firth
offshore northeast Scotland.
Business Unit and Chevron Energy Tech-
nology Co. lab personnel. For stage 1,
WorleyParsons is performing the facilities
E&P workscopes; Petrofac is carr ying out
the offshore facilities installation work;
Baker Hughes is supporting the logistics
of the polymer supply chain (including
QA/QC requirements); Honeywell is
responsible for control system changes
for each injection well that comes online;
and Archer is supporting our drilling pro-
gram. Wood is supporting some subsea
screening work as we plan for stage 2 of
Offshore: In late 2014, the company
planned to add a third platform specifically for polymer storage/injection. Was
this scheme shelved purely because of the
oil price fall, or did the company simply
decide that a phased approach to polymer
injection would be more practical?
Freeland: The project originally entered
front-end engineering and design in 2014
as a full-field greenfield development. In
2016 to develop the field at a pace aligned
with the information gained on polymer performance and to optimize the economics of
the development the project was split into two
phases. This has enabled Chevron to accelerate
polymer injection as stage 1 uses existing wells
in combination with newly drilled platform
wells and some brownfield facilities upgrades.
It will also allow Chevron to fully learn the
lessons of operating a polymer flood prior to
authorizing stage 2 (which is anticipated to be
a higher capex development).
Of fshore: Has drilling of the injector wells
started, and when will the program be completed?
Freeland: As part of the stage 1 scope, we
have appropriated funds to drill six wells – five
producers and one injector. Two polymer
injection wells were already onstream in 4Q
2017 classed as pilot wells. The stage 1 scope
is to have four more polymer injection wells
coming on in a phased program between July
2018 and 2021. One of the pilot wells will con-
tinue to inject polymer during this period also.
Of fshore: Where will these wells be placed
in relation to the existing producers, and are
you expecting the benefits to be instant, or
Freeland: The majority of wells required
for stage 1 of the project already exist; the
six new wells will be drilled between 2018
and 2023 and will be optimally placed to most
effectively polymer flood the stage 1 develop-
Of fshore: Is there the capability to vary in-
jection rates per well, depending on the per-
formance of the impacted production wells?
Freeland: Both injection and production
well rates will be adjusted based on sound
reservoir management principles.
Offshore: What are the various brownfield
modifications needed for this project?
Freeland: We are using in-line mixing
equipment which minimizes the spatial im-
pact of the new mixing facilities. As such,
the brownfield modifications are limited to
polymer pumping facilities and some new/
re-routed piping runs. Existing polymer stor-
age on the Captain facilities is used with some
small modifications required to accommodate
the expansion for stage 1 of the project.
Offshore: Does the polymer have any impact
on the produced oil, necessitating new process
Freeland: No new process equipment is
required. However, some steps will need to
be taken to minimize the impact of polymer
returns on the Captain process.
Offshore: Are the equipment and the storage
capacity sized to fit the first-phase wells only, or
for the eventual expansion of polymer injection?
Freeland: The polymer storage capacity
and equipment was installed in 1997 as part
of the original Captain development plan and
is sufficient for stage 1 with some minor modi-
fications. Requirement for additional storage
capacity will depend on the scope and timing
of potential future EOR expansion.
Offshore: Has the Phase 1 program ben-
efited in any way from Chevron’s collaboration
with other North Sea area operators and
the OGA’s polymer program?
Freeland: Chevron has taken a leading
role in the OGA’s Polymer Forum and in
the development of the industry lessons
learned document. Chevron has also col-
laborated with other forum members on
many polymer lessons learned and best
Of fshore: What is Chevron’s contribution to these programs?
Freeland: The importance of encour-
aging industry uptake of EOR was out-
lined in the Wood Maximising Recovery
Review and is an integral theme of the
Maximising Economic Recovery (MER)
UK Asset Stewardship Board. The EOR
Joint Industr y Task Group was formed in
late 2016 and comprised representatives
from Chevron, Shell, BP and Statoil, all of
which are currently developing Polymer
EOR projects on the UK continental shelf.
The Polymer EOR Starter Pack is intended
to support MER and future Polymer EOR
projects. The aim of the pack is to help those
considering future Polymer EOR projects
to move forward by learning from existing
Polymer EOR projects and understand the
value from Polymer EOR for their own assets. Chevron played a key role in sharing its
own learnings to help improve the framing,
business case, and execution of EOR. In addition, citing its experience from Captain, a
road map to Polymer EOR implementation
was produced which represents a generally
accepted view of the multiple stages that a
successful EOR project should go through
to mature from screening to implementation.
Offshore: The OGA’s recent Polymer report
mentions the need for contingency plans to
deal with the risks of injectivity loss or shear
degradation – what would cause this to arise,
and what are the planned mitigation measures
Freeland: Chevron has worked hard in
collaboration with polymer suppliers to design
chemicals that do not cause injectivity loss.
Our facilities team has designed the polymer
distribution system such that any shear degradation issues have been mitigated.
Of fshore: If Phase 1 is a success, what are
the plans for expanding the scope of polymer
EOR at Captain?
Freeland: Stage 2 represents the expansion
to our subsea wells at Captain and will benefit
from the learnings and experience we gain
during stage 1 of the project. •