Tracer release system and method of use

Abstract

The invention provides a tracer release system and method of use. The tracer release comprises at least one tracer chamber for connection to a production tubing. The at least one tracer chamber comprising at least one inlet, at least one outlet, a fluid volume and a tracer material located in the fluid volume. The tracer chamber also comprises a valve configured to selectively open and/or close the at least one outlet.

1 . A tracer release system for estimating an influx profile for at least one of the well fluids to a producing well comprising;
 at least one tracer release apparatus for connection to a production tubing, the at least one tracer release apparatus comprising;
 at least one outlet; 
 at least one tracer chamber in fluid communication with the at least one outlet; 
 a tracer material located in the at least one tracer chamber; and 
 at least one valve configured to selectively control the flow of fluid through the at least one outlet; 
   wherein the at least one valve is configured to shut in the at least one tracer release apparatus to increase the concentration of tracer molecules in a fluid volume in the tracer chamber.   
     
     
         2 . The tracer release system according to  claim 1  wherein the at least one tracer release apparatus comprises at least one inlet in fluid communication with the at least one tracer chamber. 
     
     
         3 . The tracer release system according to  claim 1  wherein the at least one valve is configured to selectively open and close the at least one outlet between a fully open position, a fully closed position, or to an intermediate position between the fully open and fully closed position. 
     
     
         4 . The tracer release system according to  claim 1  wherein the tracer material is fluid specific configured to release tracer molecules from the tracer material into a fluid in the tracer chamber on contact with a particular well fluid. 
     
     
         5 . The tracer release system according to  claim 1  wherein the tracer material is selected from the group comprising chemical, fluorescent, phosphorescent, magnetic, DNA and radioactive compounds. 
     
     
         6 . The tracer release system according to  claim 1  wherein the tracer material comprises a tracer and a carrier. 
     
     
         7 . The tracer release system according to  claim 1  wherein the at least one valve is an electrically operated valve, a differential pressure operated valve or a velocity valve. 
     
     
         8 . The tracer release system according to  claim 1  wherein the at least one valve is configured to shut in the at least one tracer release apparatus at a predetermined production flow rate and/or production fluid pressure. 
     
     
         9 . The tracer release system according to  claim 1  wherein the at least one valve is configured to divert flow into the at least one tracer chamber. 
     
     
         10 . The tracer release system according to  claim 1  comprising at least one flow restriction device configured to control the release rate of the tracer molecules from the tracer chamber of the tracer release apparatus into the production tubing. 
     
     
         11 . The tracer release system according to  claim 1  wherein the at least one valve is configured to open or close by modifying the production flow rate in the production tubing. 
     
     
         12 . A method of estimating an influx profile for at least one well fluid to a producing well with at least one influx zone to a production flow comprising:
 arranging at least one tracer release apparatus at one or more known levels of the well, wherein each tracer release apparatus comprises:
 at least one outlet in fluid communication with the production flow; 
 at least one tracer chamber in fluid communication with the at least one outlet; 
 a distinct tracer material located in each tracer chamber; and 
 at least one valve configured to selectively control the flow of fluid through the at least one outlet, wherein the at least one valve is configured to shut in the at least one tracer release apparatus to increase the concentration of tracer molecules in a fluid volume in the tracer chamber; 
   opening the at least one valve to release tracer molecules from the tracer chamber into the production flow though the at least one outlet; and   sampling of produced fluid and measuring concentration of tracer; and   estimating an influx profile for at least one of the well fluids based on the measured tracer concentrations.   
     
     
         13 . The method according to  claim 12  comprising analysing arrival time of tracer to determine inflow contributions. 
     
     
         14 . The method according to  claim 12  comprising analysing a rate of decline of the tracer concentration from each tracer location and/or tracer release apparatus location to determine inflow from each influx zone. 
     
     
         15 . The method according to  claim 12  comprising analysing characteristics of the tracer release, sampling time, and/or cumulative produced volume of the influx volumes from different influx zones. 
     
     
         16 . The method according to  claim 12  comprising controlling the opening and/or closing of the at least one valve by adjusting the flow velocity and/or flow pressure in the production tubing. 
     
     
         17 . The method according to  claim 12  comprising measuring the tracer concentrations in real time or taking samples for further analysis onsite or offsite. 
     
     
         18 . The method according to  claim 12  comprising restricting flow though the tracer release apparatus to control and/or delay the release of fluid from the tracer release apparatus to the production tubing. 
     
     
         19 . A method of estimating an influx profile for at least one well fluid to a producing well with at least one influx zone to a production flow comprising:
 providing measured tracer concentrations, the measured tracer concentrations previously obtained by analysis of samples of fluid collected from the production well, the well comprising at least one tracer release apparatus arranged at one or more known levels of the well, wherein the tracer release apparatus comprises:
 a fluid volume; 
 a tracer material located in the fluid volume; 
 an outlet to the fluid volume; and 
 a controllable valve configured to selectively control the flow of fluid through the at least one outlet; wherein the at least one valve is configured to shut in the at least one tracer release apparatus to increase the concentration of tracer molecules in a fluid volume in the tracer chamber; and 
   estimating an influx profile for at least one of the well fluids based on the measured tracer concentrations.   
     
     
         20 . A method of collecting samples for analysis in estimating an influx profile of a hydrocarbon producing well, the well comprising at least one tracer release apparatus arranged at one or more known levels of the well, wherein the tracer release apparatus comprises a fluid volume, a tracer material located in the fluid volume, an outlet to the fluid volume and a controllable valve configured to selectively control the flow of fluid through the at least one outlet, wherein the at least one valve is configured to shut in the at least one tracer release apparatus to increase the concentration of tracer molecules in a fluid volume in the tracer chamber, the method comprising:
 inducing a transient in the production flow to release at least one tracer from the at least one tracer release apparatus; and   collecting samples at a location downstream of the tracer sources after inducing the transient in the production flow.