Online tracer monitoring and tracer meter

A tracer method for online monitoring of downhole zonal contributions of oil, condensate, gas, or water mass flux of a production flow in a petroleum production well, said well having a plurality of well components, the plurality of well components comprising:

• production tubing;
• a completion void;
• a gravel pack;
• and
• surrounding permeable geological formation,
• wherein each well component acts as a delay chamber during flush out of a tracer-containing fluid out of the well, and each delay chamber, in turn, is associated with a retention time, wherein the retention time of said delay chamber is a measure of the time taken from tracer release, via the delay chamber, to tracer detection topside,
• said method comprising:
• a) arranging one or more distinct tracer carrier systems each in different production zones in said well;
• b) said distinct tracer carrier systems arranged for releasing tracers to a fluid of said production zones;
• c) said tracers having affinity after downhole release to separate phases of oil, condensate, gas, or water with corresponding zonal mass fluxes;
• d) conducting a continuous loop of the following steps (e)-(f), comprising:
• e) using an online tracer monitor, conducting sampling of tracer concentrations for at least one of the tracers in said zonal mass fluxes at a high sampling rate, said high sampling and analysis rate, up to 1 sampling/5 sec, but set and conducted at a time rate obeying Nyquist Theorem for sampling of information related to one or more variations in flow of tracer-containing well fluid and noise, wherein acquired high frequency raw data enables estimation of multiple delay chamber flush outs;
• and
• f) based on said concentration values of the tracers and the retention times associated with the delay chambers, estimating the corresponding zonal tracer fluxes and the zonal mass flux of oil, condensate, gas, or water for each delivery data point;
• g) using said one or more estimated zonal mass fluxes as input to control said production well.