Benchmarking
The NSTA have published a number of benchmarking reports about the UKCS which can be found at the links below.
Production Efficiency

Benchmarking of UKCS production efficiency and losses with interactive visuals
Unit Operating Costs

Analysis and benchmarking of Unit Operating Costs (UOC) and operating expenditure...
Recovery Factor Benchmarking

UKCS asset performance benchmarking using Recovery Factor data
Flaring and Venting

Benchmarking of the flaring and venting of greenhouse gases on the UK Continental...
Decommissioning

Statistics for a wide range of recent UKCS decommissioning activities