The UK’s petroleum reserves remain at a significant level which could sustain production for at least the next 20 years and beyond if additional undeveloped resources can be matured.

The Oil and Gas Authority’s (OGA) ‘UK Oil and Gas: Reserves and Resources’ report, shows that overall remaining recoverable reserves and resources range from 10 to 20 billion barrels plus of oil equivalent.

Overall oil and gas reserves as at the end of 2017 showed a reduction compared to end 2016. This is a result of production of 600 mmboe in 2017 exceeding additions to the reserves base as a result of Field Development Plan (‘FDP’) approvals and reserves adjustments for producing fields.

The OGA’s estimate of prospective (i.e. undiscovered) resources has been revised significantly during 2018. The OGA now considers that the mean prospective resources of mapped features (leads and prospects) in the prospect inventory is 4.1 billion boe. For the first time, the Yet-to-Find estimate also includes Prospective Resources added through Play Analysis and this contributes an additional mean prospective resources of 11.2 billion boe. This is estimated to reside in both mature and more underexplored plays, for which there are few or no mapped features.

The findings of the report include:

• The UK’s petroleum reserves remain at a significant level. The OGA’s estimate for proven and probable (2P) UKCS reserves at end 2017 are 5.4 billion barrels of oil equivalent, which could sustain production from the United Kingdom Continental Shelf (UKCS) for another 20 years or more.
• In 2017, 400 million boe were added to 2P reserves and about 600 mmboe were produced which equates to a reserve replacement ratio of 69%; with 100 mmboe matured from new field developments, 80 mmboe due to infield activities and approximately 220 mmboe reserves replacement due to field-life extensions.
• The UK’s contingent resource level (2C) is significant with a central estimate of discovered undeveloped resources of 7.5 billion boe. Much of this resource is in mature areas with 2.1 billion boe expected to be added through new field developments, 2.1 billion boe from incremental projects in producing fields, and the remaining 3.2 billion boe from undeveloped discoveries where no activity is currently being proposed.
• The maturation of contingent resources presents a significant opportunity for the continued development of the UK’s petroleum resources. This will require substantial investment in both new field developments and incremental projects.
• Exploration success in 2017 delivered an additional 181 million boe contingent resources. A key part of exploration stewardship is now to progress the many attractive opportunities within the prospective resource portfolio into drill-ready prospects, and into subsequent discoveries.
• During the last two years the OGA has undertaken an extensive exercise with the British Geological Survey (BGS) to re-evaluate the UKCS mapped lead & prospect inventory which following volumetric, economic and risk adjustments is now estimated at a mean value of 4.1 billion boe.
• The OGA has also undertaken statistical play analysis and an additional mean prospective resource of 11.2 billion boe is estimated to be contained in plays outside of mapped leads and prospects, with the proportion of gas being greater than 60%

KeyFacts Energy Industry Directory: Oil & Gas Authority