Reserves and resources

The Oil and Gas Authority (OGA) aggregation of UK reserves and resources as at the end of 2015 is based on data collected from operators during February and March 2016.

In total, 755 fields and potential developments or past discoveries, both offshore and onshore, were reviewed.

The OGA has changed the way we report Reserves and Contingent Resources this year to be compliant with the latest SPE PRMS guidelines.

Reserves have therefore been counted for approved and producing fields only. Resources from other significant discoveries where field development plans are under discussion and Extended Oil Recovery (EOR) Potential have been counted as contingent resources.   This change has resulted in a net reclassification of circa 600 million barrels of oil equivalent (mmboe) previously reported as Reserves now being reported as Contingent Resources.

OGA aggregation of UK reserves and resources

Information about the data

  • Analysis in the oil and gas tables is focused on remaining reserves.
  • UK reserves tables are presented in metric units but Appendix 1 shows field unit versions of these tables.
  • Overall summary page presents tabular figures for discovered resources only, and offers an explanatory paragraph that takes account of the estimates for undiscovered resources to arrive at a best estimate of remaining recoverable UKCShydrocarbon resources.
  • Summary tables are presented in billion barrels of oil equivalent (boe) to allow comparison of oil and gas data.
  • Appendix 2 shows historic UK oil and gas reserves, contingent resources and production figures and is the data used to generate the oil and gas reserves and resources v time charts

  • Definitions

    Estimated ultimate recovery

    Total recovery from a field, i.e. reserves plus past production


    Discovered, remaining reserves that are recoverable and commercial. Can be proven, probable or possible depending on confidence level

    Contingent resources

    Contingent resources are those quantities of petroleum estimated to be potentially recoverable from known accumulations, but the applied project(s) are not yet considered mature enough for commercial development. Includes future planned developments where development plans are under discussion that have not been approved, and “Potential Additional Resources” (PARS) which are discovered resources that are not currently technically or commercially producible.

    Undiscovered resources

    Undiscovered potentially recoverable resources in mapped leads

    Potential additional resources

    Discovered resouces that are not currently technically or commercially producible


    Reserves that on the available evidence, are virtually certain to be technically and commercially producible, i.e. have a better than 90% chance of being produced


    Reserves that are not yet proven, but which are estimated to have a better than 50% chance of being technically and commercially producible


    Reserves that at present cannot be regarded as probable, but which are estimated to have a significant – but less than 50% – chance of being technically and commercially producible