Using External Peer Review to Build Confidence of the Pelican Storage Site
10 Pages Posted: 26 Mar 2021
Date Written: March 18, 2021
[The CarbonNet Project is investigating the potential for a commercial scale, multi-user CCS network with geological carbon storage in the nearshore Gippsland Basin, Victoria in SE Australia. Sources of CO2 include the potential production of hydrogen from nearby Latrobe Valley coal fields by a consortium that is currently establishing a pilot project to produce and transport clean hydrogen from Victoria to Japan.
CarbonNet has been investigating potential storage sites and has identified a preferred site called Pelican in the nearshore. It is a 10 km by 7 km, east-west trending structural closure with excellent injectivity and effective seals comprising laterally extensive tidal/lagoonal shales and seat earths underneath well-mapped coal beds. The process used to select the preferred site for appraisal followed international best practice, aligned to DNV GL Recommended Practice (DNV-RP-J203), and has been previously reported.
CarbonNet has now acquired high quality 3D seismic data and undertaken a further range of seal and modelling studies that have confirmed the ability of the storage formation to securely and permanently store at least 125 Mt of CO2 injected at 5 Mtpa over 25 years.
In order to progress to injection at the site, the Australian regulatory regime requires that it first be Declared to be an “Identified Greenhouse Gas Storage Formation”. The Regulations set out matters to be addressed including structure and faulting, reservoir, seal, geomechanics, geochemistry well integrity and plume migration.
The Pelican site will represent the first site to be evaluated under Australian offshore legislation and as such, there is no precedent for the structure or degree of detail of the application although some general principles can be derived from analogous petroleum documentation. CarbonNet decided that the format of the application for a Declaration would comprise a series of technical modules each addressing a geological element of the application. A Summary Document is laid out to respond to each of the regulations in the form and sequence set out in the Regulations. The Summary Document layout suits evaluation by the regulator, while the supporting technical modules are suited to providing a coherent geological description.
In order to build internal, stakeholder, and regulator confidence in the Declaration document, CarbonNet engaged a panel of international experts to review the document against regulatory requirements and international norms. Panel membership was developed with consideration of:
• CO2 storage project expertise;
• technical expertise (particularly seal);
• research reputation; and
• regulatory experience.
DNV GL was engaged to additionally act as an independent chair/facilitator of the panel and to take advantage of its experience in setting standards for certification of projects. The balance of the membership, particularly their experience with existing projects, was invaluable in making an informed and credible assessment of the documentation.
The panel was provided with the draft application for review with topics allocated to subject experts. Initial comments were collated by the chair/facilitator. The panel convened in Melbourne for a two-day meeting of CarbonNet presentations and panel discussion. It held a half day closed discussion to agree an assessment of the documentation.
The panel’s assessment was that Pelican is a high-quality storage site compared to many other CO2 storage projects the panel had experience with. It was able to conclude that the documentation provided, and the technical work performed by the CarbonNet team, is of very high quality and, in the opinion of the panel, sufficient to meet all regulatory requirements pertaining to the Declaration for the Pelican storage formation. In particular, the seals for the site were effective to injected CO2 over relevant timescales.
CarbonNet has completed a comprehensive study of the Pelican storage site over many years. CarbonNet has assessed the site to have world class reservoirs demonstrate high injectivity and nearby oil and gas fields demonstrate that the seal systems are effective. It has modelled the CO2 plume and is confident that the CO2 will remain safely and securely stored for many thousands of years. This conclusion is supported by the panel of international experts that reviewed the CarbonNet documentation. The support of the panel provides strong, independent support of CarbonNet’s position and confirms the site to compare favourably with other international CO2 storage projects.
The panel report will form part of the submission to the regulator in support of its application for a Declaration of Storage at the Pelican site. It will also support the commercialisation process which commenced in late 2019.
Keywords: CarbonNet, CO2 storage
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