One of the key actions of the Wood Report was that Government and Industry should together create an up-to-date, readily accessible, digital perspective on the prospectivity and geology of the UKCS. 

To further this aim, a Technical Advisory Committee (formerly the 21st Century Exploration Roadmap Committee), which reports to the North Sea Transition Exploration Taskforce, has been responsible for a five-year plan of regional subsurface studies to support ongoing exploration initiatives and future licensing activities. 

All technical projects completed to date have been openly tendered and the Technical Advisory Committee works to ensure that studies are effectively managed and delivered to the benefit of project sponsors and ensure economic recovery. The committee is chaired by the NSTA and has representation from a cross-section of companies. 

The NSTA expectation is that all companies that hold an Exploration or Production Licence in the UK will contribute funding, data and knowledge to any future regional studies and actively participate with a genuinely collaborative spirit. 

Information on previous projects conducted as part of the initiative, including where the products of these projects can be accessed, can be found under “Completed Projects”. 

UKCS Petroleum Systems Project

Based on industry feedback solicited in 2018, the focus of future collaborative projects has shifted towards providing comprehensive databases for industry to use rather than providing detailed regional subsurface interpretations. On this basis, the Technical Advisory Committee developed a model for the UKCS Petroleum Systems Project that would be focused on delivering comprehensive, consistent subsurface databases to aid the revitalisation of exploration. 

The first year of the UKCS Petroleum Systems Project was wholly Government funded via HM Treasury budget that was made available to the NSTA during the 2018/19 financial year. The primary objective of the initial year was to compile and deliver a consistent and comprehensive geochemical database for the whole of the UKCS. This database has been built primarily from legacy geochemical data from the National Data Repository (NDR) and the British Geological Survey (BGS) but has been supplemented by new fluid analyses carried out as part of the project. The full database comprises more than 90,000 individual samples from more than 2,700 wells. In addition to the geochemical database, the deliverables from the first year of the project also include regional shallow seismic interpretation and petrophysical estimates of TOC from some of the less well understood source rocks (e.g. Devonian, Middle Jurassic). All of the products from the initial year of the UKCS Petroleum Systems Project were released in July 2019 in support of the 32nd Offshore Licensing Round and can be accessed via the NSTA’s Open Data Centre. 

The model proposed for the UKCS Petroleum Systems Project involved the initial year being funded by Government with subsequent years requiring funding by an industry participant group. The project sought a total amount of funding from a sponsor group of £1MM/year for the next 3 years. Following extensive consultation with industry, a final call for support for continuation of the project was made in March 2018, the response to which resulted in approximately £500,000/year being committed. Based on this level of support, the decision was taken by the North Sea Transition Exploration Task Force to put the project on hold to allow industry time to pick up, use and realise the value in the geochemical database and other deliverables produced within the first year of the project. 

The latest information presented to industry on the UKCS Petroleum Systems Project can be found as part of the presentations made at the Exploration Forum on the 20th June 2019. This material provides the background to the project plus more detailed information on the deliverables produced as a result of the first year of the project. 

Enquiries about any previously completed projects or suggestions for the focus of future projects should be directed to: Jo.Bagguley@nstauthority.co.uk 

Completed projects

Overview

A post well analysis of exploration and appraisal wells drilled during 2003-2013 in the Moray Firth and the UK central North Sea has been carried out. Wells fall into three categories: dry, technical success, and commercial success. The project focused on the dry wells and the technical but not commercial successes. This was a deliberate move to ensure that we captured key learnings that could be transferred across industry.

The Project objectives:

  • Fully understand the reasons why each prospect was drilled, i.e. understanding its geological and petroleum settings;
  • Attempt to understand the reasons for success and failure of wells over the 10 year period;
  • Share the main findings with the industry;
  • Test the Wood Review’s “Collaborative Model”.

Wells in the project

150 Exploration main bores plus exploration side-tracks were drilled between 2003 and 2013, by 42 Operating Companies. Of these, 98 wells have been reviewed, allowing an in depth post drill analysis of 104 segments (note on segments - one exploration well may target several superimposed petroleum objectives or well segments).

Project phases

The first project stage consisted of selecting the wells to be reviewed and establishing the template for a Post Well Analysis Sheet to summarise the main results of each well.

The second stage consisted of one-to-one workshops with operating companies to compare the pre-drill prospect description with the final well results and subsequent interpretations, in order to understand and agree the main reasons for well failure.

The third phase was to develop a selection of case histories. This involved multi-company workshops, gathering Operators who had drilled the same petroleum play in the same geological setting, and encouraging them to share their understanding of the main reasons for failure.

Final results

Final results were presented to the industry at the O&GUK Annual Conference in Aberdeen on June the 17th, 2015, at the PGC VIII conference held in London on the 29th September 2015 and at a PESGB evening lecture on the 20th of October in Aberdeen.

Copies of the Presentation, Post Well Analysis Sheet, Map and well list are below:

Overview and sponsorship

This geoscientific study was commissioned by DECC (now NSTA) as part of their Maximising Recovery Programme (OG-MRP) contract with the British Geological Survey (BGS).

The study was operated as a Joint Industry Project (JIP) with approximately 50% Government funding and 50% industry funding, with a contribution from Oil & Gas UK. The project started in January 2015. Oil & Gas UK continued their support while responsibility for the whole 21XCRM project management transferred to the NSTA towards the end of the project. For the Palaeozoic study, BGS provided the day to day project management, with a JIP Board and Technical Steering Committee, of which the NSTA and Oil & Gas UK were active participants.

The project was delivered prior to the opening of the 29th Licencing Round, and sponsors had exclusive access to the results until after the Round was closed.

The high level aim of the project was to:

    • Encourage research deeper and wider than the conventional hydrocarbon horizons
    • Develop a strong, consistent regional data-set to provide a platform for more specific oil & gas exploration studies
    • Develop a new scientific understanding that de-risks some of the critical play elements and that  stimulates new ideas for plays and prospectivity
    • Provoke new data acquisition, additional analysis and interpretation programmes that may lead to increased exploration activity

Project scope, plan and deliverables

The project had three phases which covered the Devonian and Carboniferous stratigraphic intervals in the following areas

  • Central North Sea/Mid North Sea High
  • Moray Firth/Orcadian Basin
  • Irish Sea

Delivery of final results from the Central North Sea/Mid North Sea High area was made to Sponsors at the end of March 2016 and was tied in to the release of seismic data from the government funded acquisition programme, giving industry new insights into key areas of the North Sea. Subsequent products from the Irish Sea and Orcadian Basin areas were delivered to Sponsors at the end of May 2016, marking the end of the 21CXRM Palaeozoic project.

Project results have been delivered digitally and include interpretations of seismic, well and gravity data, along with burial/uplift/maturity modelling, source rock geochemistry studies and palaeographic reconstructions, to inform the location of prospective Carboniferous and Devonian play elements.

Maps and a Powerpoint which illustrate the Palaeozoic study

Following the closure of the 29th Licence Round and subsequent licence awards, the results of the Palaeozoic Study are now being published via the BGS’s Offshore Geoindex.

Links to the Offshore Geoindex can also be found on the NSTA’s Open Data Portal.

Overview

As part of the 21CXRM initiative and in collaboration with the 21CXRM Technical Advisory Committee, the NSTA awarded various contracts for an initial phase (Phase 1) of petroleum system related studies for both the East Shetland Platform and South West Approaches areas. The main objective of the studies was to enhance industry knowledge and understanding of both areas ahead of the 31st Frontier Licencing Round, with particular focus on gaining more insight into the structural evolution and source rock potential of the two areas.

The projects in the East Shetland Platform were awarded to FROGTECH and IGI Ltd whilst the South West Approaches projects were awarded to Getech and BGS. All of these studies were wholly funded by the NSTA and were recently released as part of the wider 2016 Government Seismic Data release on the 27th November 2017.

Results and Deliverables

The results and deliverables from all of these Phase 1 studies can be downloaded directly from the NSTA’s Open Data Centre.

This study was designed to build on the understanding of the petroleum systems of the SW Approaches and East Shetland Platform and specifically focused on the source rock potential within these areas. This involved obtaining new geochemical analyses from potential source intervals as well as looking at AFTA to help constrain better understanding the basin history with estimates of uplift and erosion.

Phase 2 of these studies were funded by the NSTA and a small industry sponsor group which had exclusive access to the deliverables ahead of the 31st Frontier Licensing Round. The project was undertaken by APT on behalf of the participants. Following the licence awards in the 31st Round and in line with the agreement in place with project sponsors, the results of the Phase 2 project have now been released and can be downloaded via the NSTA's Open Data Centre.

HPHT (high pressure, high temperature) fields in the Central North Sea (CNS) account for a significant portion of UK total production. Expediting the successful exploitation of new HPHT structures in the UKCS can play a major role in maximising economic recovery and extending the asset life of existing infrastructure. While HPHT conditions are recorded in a number of UKCS basins, by far the largest resource attributable to HPHT producing fields, discoveries, and mature prospects lies within the Central Graben of the CNS. 

This pressure cell study focusses on the Jurassic and Triassic stratigraphic intervals in the CNS. The objectives of this study are to provide a regional understanding of overpressure distributions or pressure cells in the Central North Sea together with a supporting QC’d well pressure database. This will: 

  • support improved mapping of overpressure distributions for prospective plays,
  • develop an understanding of the subsurface pressure regimes onto which the HPHT portfolio of leads and prospects can be mapped and distinguished from the NPNT (normal pressures and temperatures) portfolio,
  •  provide a publicly released dataset on which further research and analysis can be based, through universities, industry collaboration, etc. without the barrier of high data costs and complex data licensing arrangements,
  •  help identify gaps in the data that is currently available.
  • stimulate exploration activity around key producing infrastructure in a timely manner
  • support more accurate models for top seal integrity and column heights modelling, therefore reducing volumetric uncertainty,
  • provide a dataset that can be used to help polarise the potential for carbon capture and storage (CCS) in Triassic-Jurassic reservoirs.

This study combines well pressure data with historic and published structural interpretations to generate a pressure cell map for the pre-Cretaceous strata of the UK CNS. A pressure dataset comprising 194 wells was generated from released well data on the National Data Repository (NDR) by Ikon Science Limited (Ikon Science). Pressure cells were interpreted from the well data, based on aquifer overpressure interpretations. Pressure cell boundaries were derived from structural interpretations in the published literature and industry reports.