The UK saw an increase in oil production by around 100,000 barrels per day (b/d) last year but new field developments have declined.
The largest contribution came from fields that were brought online in the second half of 2014, according to the US Energy Information Administration (EIA).
It added “significant” increases also came from fields that came online in 2015 and from improved performance of the nation’s largest producing field, the offshore Buzzard site.
The UK is said to be the second largest liquids producer in Europe – after Norway – producing one million b/d in 2015.
More than 97% of production came from offshore fields where petroleum development projects have long lead times, the EIA stated.
However it found producers have begun to slow plans for new development in response to the current low oil prices.
The report added: “Given the long lead times associated with offshore production, this will likely have ramifications in the two-to-five year timeframe (2018/21).”
The number of field development plans that were approved by the UK Government last year was less than half the number approved in 2013 or 2014.
The EIA said: “The current lull in both new field approvals and incremental development approvals could lead to significant production declines in the United Kingdom in 2018 and beyond. However, in 2016 and 2017, several already-approved fields where investment is already committed are expected to begin production, at least partially offsetting production declines from existing fields.”
Last month Oil & Gas UK warned investment in new oil and gas projects in the North Sea is “collapsing”.
Earlier this month Chancellor George Osborne announced tax breaks for the industry.