The Multiple Application Re-injection System or MARS enables any process to be fitted to any well at any time.  This is achieved by establishing a retrofit coaxial access port which has been compared to “a USB port” for a wellhead.  Unplanned maintenance therefore no longer requires major field shutdowns or infrastructure decommissioning; access is simply achieved via the “USB port”. This technology delivers a low cost and flexible field development strategy for new and existing oil fields.

MARS establishes the wellhead as the unit of production, enabling production optimisation systems to be mounted directly onto the Xmas trees.   The principle is simple; by introducing a coaxial flowpath insert into the Xmas tree, well fluids are directed externally to a flow loop which houses a processing technology.  The flow is returned to the wellhead and back into the existing flowline infrastructure.  As the processing hardware is installed between the existing isolation barriers, the need for expensive, high risk well intervention, field shut down or flowline decommissioning is eliminated.

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The challenge to facing Operators can be summarised as follows:

    • To maximise the NPV of assets
    • To minimise HSE Risk
    • To maximise incremental recovery from assets
    • To minimise reservoir risk
    • To minimise CAPEX
    • To lower OPEX
    • To maintain a flexible strategy for production optimisation
    • To allow for low cost intervention for maintenance

 

These seemingly diverging challenges can be made to converge when you begin to realise the range of production optimisation opportunities realised by literally installing “any process on any well”.  The technologies and the range of possible solutions enabled by MARS are constantly evolving.  The number of existing or emerging processing technologies that can be fitted on to any wellhead with minimal risk includes:

Download Product Literature here

Download Product Literature here

Download Product Literature here

Download Product Literature here

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BP KING, Gulf of Mexico, MARS enabled Multiphase Pumping
In December 2007, BP successfully commissioned two 1.5 MW subsea multiphase pumps on the KING project.  The significance of this project cannot be understated; being almost twice as deep and three times longer than any previous multiphase pump installation.  It represents several industry milestones, including:

    • the first Subsea Multiphase Pump in the Gulf of Mexico
    • the first Subsea Multiphase Pump for BP
    • the deepest Subsea Multiphase Pump installation to date at 1700m
    • the longest multi-phase pump tieback, at 27km
    • production is estimated to increase by approx 20%; and
    • economic field life is expected to be extended by over 5 years

In the KING project, MARS offered BP a low risk method of gaining access to their wellstream. This was achieved without breaking into the existing flowline system and additionally minimizing well downtime.

Each of the two pumps were installed on separate foundations adjacent to the existing wellheads.   The MARS system was installed onto a “Universal Work Platform” or UWP which in turn presented two vertical CVC hubs to enable jumpers to be installed from pump to tree. 

MARS Universal Work Platform (UWP)

In addition to using MARS, BP also selected DES’ proprietary POSSibilties (Production Optimisation Simulation Software) to evaluate various enhanced recovery opportunities.  Working closely with the BP reservoir team to establish a base case production profile, the software was able to run multiple parallel simulations to quickly screen various artificial lift solutions.  It subsequently compared various different pumping technologies performance throughout the life of field to determine the optimum pump type, size and location. 

DES were fully integrated into the BP delivery team throughout their ‘CVP’ process providing expertise and resource for:

    • Preliminary screening
    • Process engineering
    • Hardware specification
    • Project management & execution
    • Installation and Commissioning

MARS deployment on BP KING

SHELL BITTERN, UK North Sea, MARS enabled Reservoir Stimulation
To enable optimum production from existing subsea wells, Shell required chemical (scale) squeeze approx every 6 months.  By upgrading the subsea trees to accept MARS, Shell were able to:

    • Remote ROV subsea operations
    • No modu or diver requirements
    • Reduce shutdown time
    • Reduce installation, mob and demob times
    • Reduce overall vessel costs(cheaper vessel and shorter lease)
    • Pump wells more frequently(increased weather window)
    • Pump multiple wells in single campaign
    • Reduce environmental risk  

Two systems are being retrofitted subsea onto existing hardware while the third system will be installed onto the next operational Xmas tree during SIT.   The MARS assembly with modified choke effectively gave the Operator a safe access into the reservoir and pipeline system.

Shell Bittern pumping skid

 

Shell Bittern MARS SIT test

TOTAL MEDIDOR, Angola, Subsea multiphase metering and allocation sampling package in West Africa

In 2008, Total will install their first MARS enabled multiphase metering/sampling package as part of the Medidor project in West Africa. 

The challenges facing the team were significant:

    • Install on operational field - 1400m water
    • Defining deepwater key tree interfaces
    • Engineering spec developed from original drawings
    • Soft landing protection and lock down equipment
    • Taking measurements upstream of the choke
    • Providing sampling for meter verification and calibration
    • Maintain choke systems
    • Capability to install and retrieve Measuring Equipment
    • Test the interface system for additional applications
    • Provide a control and Communication interface for tieback

Working with both choke and xmas tree manufacturers DES were able supply a complete MARS solution onto subsea hardware in situ which had not been specifically designed for maintenance or for retrofitting processing solutions.  By providing continuous 24/7 multiphase metering capability, Total will increase ultimate recovery from the reservoir through optimised management of individual wells.

The MARS method in this case has several advantages over existing traditional installation methodologies, including:

    • MARS uses tree installed double barriers to isolate well & flowline
    • MARS uses no additional barriers during installation
    • MARS minimises environmental effluent containment issues
    • MARS uses standard wellhead interfaces, intervention process & tooling
    • Low cost and low risk installation and easy retrieval for repair
    • MARS uses all ‘Pre- Qualified’ components for installation

MARS enabled multiphase metering and sampling

In addition, meter operation and accuracy is optimised due to:

    • Meter installed upstream or downstream of the choke to optimise accuracy
    • Meter verification via in stream sampling - delta ‘P’ across choke
    • Meter capable of retrieval for repair and/or upgrade
    • Meter installed with Piggy back independent control system
    • Reduced cost & risk of intervention using light DSV/ROV systems
    • Meter can be upgraded to add in additional PO Applications

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