ExxonMobil CO2 pipeline – Coming under increasing pressure

This is the fifth SPS post on the subject of the ExxonMobil ‘Solent CO2 Pipeline Project.
The front page summary post, which is the best place to begin for the reader new to the subject, can be found by clicking th is link.
Alternatively, the full list of SPS Posts on the subject can be found by clicking this link.

This post builds on our previous articles, homing in on the unexplained details behind the glossy marketing front presented by the current ‘Non-statutory consultation’.

Several of the SPS team have now attended ‘Solent C0₂ Pipeline’ roadshow exhibitions and listened to presentations given by various members of the project team, most recently at a well-attended meeting of the New Forest Consultative Panel in Lyndhurst on 5 September.

Attendees at the Lyndhurst event included representatives from New Forest District District Council, the National Park Authority and numerous town and parish councillors representing the New Forest, Waterside and Solent shoreline communities. Solent Protection Society were invited along with representatives of Defra agencies, environmental bodies and groups representing the many recreational users of the Forest, the ramblers, cyclists, equestrians and wildlife watchers.

The first item on a packed agenda was a presentation on the Solent CO₂ Pipeline Project from Jacobs and ExxonMobil. Fronted by Philippa Garden from Jacobs, the former Head of Communications and Engagement for the ExxonMobil ‘Southampton to London Pipeline’ (SLP) project, Philippa now leads the public relations drive for the Solent CO₂ Pipeline project. Philippa was joined by ExxonMobil chemical engineer Alison Segun who had previously helped front the Development Consent Order bid to the Planning Inspectorate for the SLP project.

The presentation gave a high level picture of the project, with selected illustrations and quotations from the summary brochure delivered in a tone which suggested that the team considered it a ‘done deal’. A reasonably slick marketing presentation but one which inevitably prompted ‘engineering’ and ‘programme management’ questions for which convincing responses were light.

The questions and responses included the following topics, which we’ll take in turn below.

Pipeline Pressure

The first question was raised by a clearly well-informed councillor from Lymington and Pennington, concerned about the pressure at which the CO₂ would be running in the overland pipeline. The response was direct and unequivocal, ‘The CO₂ in the pipeline will be at high pressure’.

Asked why, when the established carbon capture and storage projects at Hynet North West and Humber East are running overland CO₂ pipelines at low pressure, the reply was that ‘they thought’ that high pressure was necessary to facilitate the CO₂ injection into the proposed sub-sea aquifer.

Why does the pressure matter?

At low pressure, carbon dioxide is in gaseous form and its flow through an underground pipeline should be relatively benign. However, when pumped at high pressure, in its dense liquid form, transportation by pipeline is a significantly higher risk operation. To appreciate the risk, we refer the reader to the Huffpost article on ‘The Gassing of Satartia’ in 2020. (Click the image below to read the piece.)

***^{The Satartia CO₂ pipeline rupture, Mississippi, 2020}***

This is the risk that ExxonMobil propose to introduce to communities by the burying of a supercritical high pressure CO₂ pipeline across the New Forest or the Isle of Wight. The company should not be surprised if residents across the region voice strong concerns over the risks to families and wildlife. Unless, of course, they have absolute faith in ExxonMobil’s commitment to safety and maintenance.

Why might the pipeline fail?

The project team drew attention to the ‘pigging’ stations which will be constructed at strategic intervals along the pipeline, quoting from the project’s brochure that “these are part of the maintenance system that ensures that the pipeline remains safe.”

Let’s unpick that last statement.

It seems that “The primary purpose of the pig launcher/trap is to enable dewatering during commissioning and pigging either as part of commissioning or during operation.” (Ref: ‘Design and Operation of CO2 Pipelines’, Det Norske Veritas, 2010 – clink link to read).

It’s worth considering that need for ‘dewatering’. CO₂ is corrosive and will eat through the steel used in petroleum pipelines if contaminated with even small amounts of water. It is also likely that the method by which the CO₂ would be captured would result in component traces of water.

If you live near the site of a proposed pigging station, you might also like to know that since CO₂ pipelines also run at significantly higher pressures than natural gas pipelines, they will require energy-intensive compressor machinery running at these stations in order to keep the pipeline CO₂ in a liquid state.

If you didn’t quite catch the scale of these ‘pigging stations’, note that they will typically have a footprint of 90m (300 feet) square , with internal structures up to 4m (13 feet) high, securely and permanently fenced from outside interference. These are not just to be installed just inland from the coastal boundary, but we were told at Lyndhurst that they might be placed at any significant change of direction of the pipe run – something you’ll not actually find out until ExxonMobil already have agreement on the selected corridor.

Like icebergs, it appears there is rather more under the ground, as this image of a pigging station under construction shows.

The Undersea Pipeline Option

Why were the obvious sub-sea routes not offered for consideration in this consultation? A fundamental question that has exercised many at the consultation events.

The reason given to the Lyndhurst audience was, surprisingly, not one of cost, but in consideration of the options at the western end of the Solent. Routing the pipeline under Hurst Spit has been deemed impractical given the instability of the spit and, ‘as many sailors will know’, the tidal stream through the Hurst Narrows is fast and the seabed fairly dynamic and so it ‘would not be possible to lay a pipeline there’.

Let’s explore that ‘fact’ further, considering other areas with high tidal flows. Engineers have already successfully delivered a massive tidal energy project in the Pentland Firth, and a major gas pipeline between Cluden and Brighouse Bay between Northern Ireland and Scotland, both channels with significant tidal flows. With even more experience available from UK and Norwegian pipeline projects in high tidal flow areas of the North Sea, the excuse given by ExxonMobil for avoiding Hurst Narrows simply lacks credibility. With regard to the dynamic nature of the seabed, we understand that use of concrete sleeving to the steel pipeline with appropriately designed saddles at the pipe junctions would address this point.

While not highlighted at the Lyndhurst presentation, it is the likely additional costs associated with an undersea route that provides ExxonMobil’s reason for excluding the option.

Given the risks, however, the perceived high risk associated with the current intention to pump dense, liquid form CO₂ overland close to communities and livestock would suggest that if transmission by pipeline is inevitable, then the additional cost of selecting the undersea route would be worth it.

Subsea Storage vs Shipping by sea

The presenting team were asked when the UK Government’s strategic direction for the surface shipping of captured carbon from southern UK sources by sea to established North Sea and Celtic Sea storage sites had been changed to a pipeline to an unverified potential storage location in the English Channel?

Looking closer at the UK Department for Energy Security & Net Zero (DESNZ) guidance for CCUS Track-2 guidance we find that re-use of the existing, proven Hynet and East Coast storage sites was deliberately excluded by the Government to new bidders to force the exploration of the two additional storage options committed by its original Carbon Capture Usage & Storage (CCUS) ambition.

The speakers at Lyndhurst did not rule out shipping, acknowledging that liquified CO₂ could still be shipped out from Southampton by tankers to another location. Interestingly, Le Havre might well provide a lower risk fallback option for ExxonMobil depending on how the French and European CCUS strategies evolve.

Analysis of the relative business cases for transport by sea or by pipeline needs careful consideration. If the cost over 30 years of building a pipeline and drilling injection wells is cheaper than the cost of shipping the captured CO₂ over the same period, then the business case for the pipeline might stack up. The elapsed time for construction of purpose-built tankers is around two years and we understand that the shipyard slots in Korea and China are booked out for the foreseeable future.

However, surely existing Exxon Liquified Natural Gas tankers could be repurposed? After all, north of the border, industries in the Central Belt of Scotland are already planning to send captured CO₂ to the Acorn storage sites thanks to National Gas Transmission repurposing an existing onshore natural gas pipeline in the SCO₂T Connect project.

At the end of the day, the English Channel storage site is still unlicenced and unevaluated, and with the only significant upstream generation of industrial carbon being ExxonMobil itself, there are still far too many questions which need carefully considered and fully costed answers.

Programme Management

As we’ve highlighted in previous posts, ExxonMobil Fawley are very late entrants into the UK CCUS game and are grasping opportunities to catch up by fast-tracking an overall programme of work. Thanks to the late start, the programme is now forced by the evolution of the DESNZ strategy to rely on the unquantified and unqualified English Channel subsea storage option in order to attempt to contain costs.

At this point, it may help the reader to have a basic appreciation of the Front End Loading project management process used in this industry sector. Take this link to a readable Wikipedia overview.

The transport and storage infrastructure being reused by other existing CCUS hubs such as Hynet and Humber East, are designed and built to mainly accommodate local industry carbon emissions reduction from refineries and cement plants. Most of these facilities have already gone through FEED Design and are about to move into the Execute phase where changes are frowned upon and the cost models are fixed. In other words, it’s probably already too late for ExxonMobil to agree realistic commercial terms for shipping captured CO₂ from the Solent to these storage sites, even if the current DESNZ strategy would permit that action.

Alison Segun confirmed that ExxonMobil is driving both the Pipeline project and the Storage project in parallel, acknowledging that the North Sea Transition Authority has yet to make a decision on whether to grant exploration and storage licences for the English Channel site.

A rudimentary understanding of risk management would suggest that the overall risk of delay, cost overrun or outright failure of the overall programme by running these two projects in parallel is high. Our concerns are magnified by the UK Government’s parallel effort to streamline the delivery of its constantly evolving industrial decarbonisation strategy. Shortcuts in process assurance will add further risk.

We will be looking to local Members of Parliament to ensure that DESNZ – the Department of Energy Security & Net Zero – performs the necessary due diligence before committing any public funds to this venture.

Environmental Mitigation and Habitat Restoration

One of the audience members at the Lyndhurst meeting raised the concern that the continued landscape scarring in parts of the Forest following the installation of the Wytch Farm to Fawley pipeline in 1989. Experience from this might cast doubt on ExxonMobil’s high level commitments to biodiversity net gain.

The meeting was told that while ancient woodland would, where possible, be respected, there would be an unavoidable loss of trees and hedgerows, together with the associated flora and fauna. On the plus side, we were informed that the consequent destruction and eventual reinstatement would be performed in accordance with the appropriate ‘British’ or ‘Utility’ standard for ‘the management of trees on development sites’. The actual quality of reinstatement would be the subject of negotiations with affected councils and landowners.

(It was not clear whether the audience were reassured at this point.)

In summary

The front-runners in the UK CCUS game are all centred around existing transportation and storage facilities associated with established offshore oil production operations. In the main these are co-located with many different refinery, chemical and cement industrial sites, each with quantifiable carbon generation.

Around the Solent, the industrial decarbonisation play is coming from a long way behind with a singularly limited source of CO₂ emissions. There is really only one significant industrial source of carbon emissions in the Solent regions, and that is the ExxonMobil facility at Fawley. While there are a few companies of note included in the vast number of entities listed as being ‘members’ of the Solent Cluster, the single biggest emitter of CO₂ by a very large margin is ExxonMobil.

The Esso Petroleum facility at Fawley is now seventy years old, having been designed to operate for thirty. The current plan is to keep the operation going for another thirty years by reducing its carbon emissions over that timeframe.

Over the course of that time, the market for its current product range will change and the need for its diesel production will drop. Perhaps it would make rather more sense to focus further low carbon hydrogen production in the industrial heartlands to the north where the Hynet, East Coast and Scottish CCUS infrastructures already have a significant head start.

Perhaps the decarbonisation of Fawley as it ramps down its traditional product line could follow the French direction and be performed by Direct Air Capture techniques? Mind you, take a look at the DESNZ strategic direction there and you’ll see that Solent Cluster seem to have missed that boat also.

ExxonMobil need a carbon capture solution in order to keep operating one of the UK’s biggest refineries, supplying low sulphur diesel and aviation fuel to Heathrow via the Southampton to London pipeline. The DESNZ will undoubtedly be mindful of this, as it assesses any application from ExxonMobil for a pipeline Development Consent Order, since it cannot afford to lose the refining and supply capacity that comes out of the Fawley plant.

There are an enormous number of risk and cost factors which need to be balanced before any agreement can be made for the investment of significant amounts of public money in the Fawley operation.

From comments passed to SPS by various local sources, it would seem that a fundamental prerequisite for significant investment in new infrastructure at Fawley, would be improvements to current maintenance practices, which appear currently to be ‘reactive’ rather than ‘predictive’, ‘fix on fail’ as opposed to ‘upgrade on plan’.

The OpenDemocracy articles

Please do not leave this post without reading the two articles referenced below.

Written by Ben Webster, a professional journalist with 24 years at the Times, 11 of them as environment editor. Here writing as a freelance, his articles reflect the value and balance that professional journalism can bring when not subject to the short arm of the editor and the longer arm of the proprietor.

These articles are well worth a few more minutes of your time.

If you have relevant industrial and/or geological information which could help with our articles, please send via email in confidence, to the following address:
exxon@solentprotection.org

This is the fifth SPS post on the subject of the ExxonMobil ‘Solent CO2 Pipeline Project.
The full list of SPS Posts on the subject can be found by clicking this link.
To read the next in the series, click here.