The generally accepted methodology of sequentially pre-testing the output of one well at a time is one way to measure flows and characterize wells in offshore facilities. The averages are then combined for a total production figure that neither considers any changes between each test nor any fluctuations in production (e.g. slugging) during the test. Very little useful information about the condition of each well is obtained in this way. Sometimes, multiphase meters replace separators on the platform for well testing purposes, but even then information is received only intermittently. Any sudden change in reservoir activity will probably not be noticed, and there is very little opportunity to determine what is happening downhole.
Installing a multiphase meter as close to each well as possible results in a number of benefits. Firstly, the production from each well is monitored continuously with little or no manual labor. This can be used for allocation purposes as an addition to – or even as a replacement for – intermittent well testing. Secondly, operators are instantly able to determine production changes – like water breakthrough, increased gas/oil ratio, etc. This feedback may then become a guide for remedial action to rectify the situation and let personnel on the surface know whether the condition is improving or not. Thirdly, by matching well flow rates as measured by the multiphase meters with early projections, reservoir engineers are able to better understand the dynamics of the reservoir and update their 3D models and manage the wells accordingly. In this way, production can be maximized while assets are optimized.