System for determining sealing in a wellbore

Abstract

A sealing system is provided for use in a wellbore ( 1 ) formed in an earth formation whereby a stream of fluid produced from the earth formation ( 6 ) flows through the wellbore to surface ( 3 ). The sealing system comprises a sealing device ( 18 ) arranged to seal a selected portion of the wellbore from the stream of produced fluid, a compound arranged to be absorbed by fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion, and detection means ( 16 ) operable to detect said compound in the stream of produced fluid.

1 . A sealing system for use in a wellbore formed in an earth formation whereby a stream of fluid produced from the earth formation flows through the wellbore to surface, the sealing system comprising a sealing device arranged to seal a selected portion of the wellbore from the stream of produced fluid, a compound arranged to be absorbed by fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion, and detection means operable to detect said compound in the stream of produced fluid, wherein the sealing device is arranged to be in contact with said fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion, characterized in that said compound is included in the sealing device. 
   
   
       2 . The sealing system of  claim 1 , wherein the sealing device is movable between an active mode in which the sealing device prevents fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion, and an inactive mode in which the sealing device allows fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion. 
   
   
       3 . The sealing system of  claim 2 , wherein the sealing device includes a swellable material that swells upon contact with a selected fluid, and wherein the sealing device moves from the inactive mode to the active mode by swelling of the swellable material. 
   
   
       4 . The sealing system of  claim 3 , wherein said swellable material includes an elastomer. 
   
   
       5 . The sealing system of  claim 3 , wherein the selected fluid comprises fluid produced from the earth formation. 
   
   
       6 . The sealing system of  claim 5 , wherein the stream of produced fluid flows through a conduit extending in the wellbore, and wherein the sealing device is an annular sealing device arranged between said conduit and one of the wellbore wall and another conduit extending in the wellbore. 
   
   
       7 . The sealing system of  claim 6 , wherein the sealing device is a packer arranged to seal an annular space between the conduit and the wellbore wall. 
   
   
       8 . The sealing system of  claim 1 , wherein said compound is selected from the group consisting of organic materials, inorganic materials, radioactive materials, and biochemical materials. 
   
   
       9 . The sealing system of  claim 8 , wherein said compound is selected from the group consisting of Halogen substituted carboxylic acids and Halogen substituted alcohols. 
   
   
       10 . The sealing system of  claim 9 , wherein said compound is selected from the group consisting of Halogen substituted decanoic acids and Halogen substituted decanols. 
   
   
       11 . The sealing system of  claim 9 , wherein said compound is selected from the group consisting of Chloro substituted carboxylic acids and Chloro substituted alcohols. 
   
   
       12 . The sealing system of  claim 11 , wherein said compound is selected from the group consisting of Chloro substituted decanoic acids and Chloro substituted decanols. 
   
   
       13 . The sealing system of  claim 1 , wherein the detection means is a gas chromatography mass spectrometer, a gas chromatography electron capture detector, a high performance liquid chromatography-mass spectrometer, a high performance liquid chromatography-fluorescence detector, an atomic adsorption spectrometer, an atomic emission spectrometer, an inductive coupled plasma mass spectrometer, an immunological detection device, an electron microscope, a light microscope. 
   
   
       14 . The sealing system of  claim 1 , comprising a plurality of said sealing devices, a plurality of said selected wellbore portions, and a plurality of said compounds, wherein for each said selected wellbore portion a respective one of the sealing devices is arranged to seal the selected wellbore portion from the stream of produced fluid, and a respective one of said compounds is arranged to be absorbed by fluid from the earth formation entering the stream of produced fluid via the selected wellbore portion, and wherein the detection means is operable to detect each said compound in the stream of produced fluid. 
   
   
       15 . The sealing system of  claim 14 , wherein said compounds have mutually different characteristics detectable by the detection means. 
   
   
       16 . (canceled)