Subsea metering on individual wells is only effective when the meters are accurately calibrated, so that production efficiency can subsequently be improved.

Proserv was approached by a multinational operator to provide a system that could take production samples to support subsea meter calibration at water depths of 2,500 metres, in West Africa.

Given the different water salinities from the wells in question, coupled with a low water content, sufficient sample volume was required to ensure analysis could be carried out accurately.

Proserv provided an ROV operated, manifold mounted, system that allowed for the safe capture and containment of up to 24 litres of sample per run.

The system had the following features and benefits

12 litre slops containment
12 litre chemical back-flush
Trace heating on sample cylinders
Real time pressure and temperature indication
Visual indication of sample volume, verifying sample taken

With the provision of subsea samples, the operator could calibrate the meters depending on well line-up, thus improving reservoir understanding and production management of the wells.

Improved subsea metering also supports maximising economic recovery, through the reduction of well downtime while physical samples allow for inlet chemistry of the pipeline to be better understood.