Hydrocarbon detection in annulus of well

Abstract

Disclosed is an apparatus for completion of a well. The apparatus includes a tubular configured to be disposed in a wellbore penetrating the earth where an annulus region is defined between an exterior surface of the tubular and a wall of the wellbore. The apparatus further includes a plurality of sensors disposed in the annulus region and configured to sense hydrocarbons during cementing of the tubular to the wall of the wellbore. A receiver is disposed remote from the wellbore and configured to receive measurement data from the plurality of sensors and to provide an indication if hydrocarbons are sensed in the annulus region.

What is claimed is: 
     
         1 . An apparatus for completion of a well, the apparatus comprising:
 a tubular configured to be disposed in a wellbore penetrating the earth, an annulus region being defined between an exterior surface of the tubular and a wall of the wellbore;   a plurality of sensors disposed in the annulus region and configured to sense hydrocarbons; and   a receiver disposed remote from the wellbore and configured to receive measurement data from the plurality of sensors and to provide an indication if hydrocarbons are sensed in the annulus region.   
     
     
         2 . The apparatus according to  claim 1 , wherein the receiver is disposed at a drilling rig and the indication is provided to a drilling operator. 
     
     
         3 . The apparatus according to  claim 2 , further comprising a computer processing system configured to receive the measurement data from the plurality of sensors and to determine if hydrocarbons are present in the annulus region. 
     
     
         4 . The apparatus according to  claim 3 , wherein the computer processing system is configured to provide an alarm to a drilling operator upon detection of hydrocarbons in the annulus region. 
     
     
         5 . The apparatus according to  claim 2 , further comprising a blowout preventer disposed at a surface of the earth and coupled to the tubular, the blowout preventer being configured to close upon receipt of a command from the drilling rig. 
     
     
         6 . The apparatus according to  claim 1 , wherein the plurality of sensors are coupled to the tubular. 
     
     
         7 . The apparatus according to  claim 6 , further comprising bands configured to secure the plurality of sensors to an outside surface of the tubular. 
     
     
         8 . The apparatus according to  claim 1 , wherein one or more sensors in the plurality of sensors are configured to indirectly sense gas or oil by sensing temperature, pressure, or fluid density. 
     
     
         9 . The apparatus according to  claim 1 , wherein one or more sensors in the plurality of sensors are configured to chemically sense gas or oil. 
     
     
         10 . The apparatus according to  claim 1 , further comprising a fiber optic cable coupled to the receiver and to the plurality of sensors and configured to communicate sensor data from the plurality of sensors to the receiver. 
     
     
         11 . The apparatus according to  claim 1 , further comprising a battery configured to be disposed in the annulus region, the battery comprising a plurality of electrodes configured to be immersed in a fluid disposed in the annulus region to provide an electrolyte to the battery. 
     
     
         12 . The apparatus according to  claim 10 , further comprising a regulator coupled to the battery and configured to provide regulated voltage or current output. 
     
     
         13 . The apparatus according to  claim 1 , wherein one or more sensors in the plurality of sensors comprises a plurality of electrodes configured to be immersed in an annulus fluid that serves as an electrolyte in order for the plurality of electrodes to generate an electrical signal responsive to the annulus fluid. 
     
     
         14 . The apparatus according to  claim 1 , wherein the plurality of sensors are configured to sense a flow of hydrocarbons in wet cement during cementing of the tubular to the wellbore. 
     
     
         15 . The apparatus according to  claim 1 , wherein the plurality of sensors or a subset of the plurality of sensors are disposed between a shoe disposed at a distal end of the tubular and a float collar disposed within the tubular. 
     
     
         16 . The apparatus according to  claim 1 , further comprising a wireless transponder disposed at an entrance to the wellbore and configured to wirelessly communicate the measurement data from the plurality of sensors and to the receiver. 
     
     
         17 . A method for completion of a well, the method comprising:
 disposing a tubular in a wellbore penetrating the earth, an annulus region being defined between an exterior surface of the tubular and a wall of the wellbore;   disposing a plurality of sensors in the annulus region, the plurality of sensors being configured to sense hydrocarbons;   receiving sensing data from the plurality of sensors using a receiver disposed remote from the wellbore; and   using the sensing data to provide an indication with an indicator or display coupled to the receiver to indicate if hydrocarbons are sensed in the annulus region.   
     
     
         18 . The method according to  claim 17 , further comprising cementing the tubular to the wellbore and sensing for the hydrocarbons during the cementing using the plurality of sensors. 
     
     
         19 . The method according to  claim 17 , further comprising powering one or more sensors in the plurality of sensors using a battery comprising a plurality of electrodes configured to be immersed in an annulus fluid to provide an electrolyte to the battery. 
     
     
         20 . The method according to  claim 17 , further comprising calculating a first or second derivative of an output of one or more sensors in the plurality of sensors using a computer processing system to detect a presence of hydrocarbons in the annulus region or a rate of change of hydrocarbons entering the annulus region. 
     
     
         21 . The method according to  claim 17 , further comprising automatically actuating a blowout preventer upon an indication of hydrocarbons being present in the annulus region. 
     
     
         22 . A non-transitory computer-readable medium comprising computer-executable instructions for completion of a well by implementing a method comprising:
 receiving outputs from a plurality of sensors configured to sense hydrocarbons and disposed in an annulus region defined by an exterior surface of a tubular disposed in a wellbore penetrating the earth and a wall of the wellbore;   detecting a presence of hydrocarbons in the annulus region using the outputs; and   providing an indication if the presence of hydrocarbons is sensed.   
     
     
         23 . The medium according to  claim 22 , wherein the plurality of sensors sense for the presence of hydrocarbons in the annulus region during cementing of the tubular to the wall of the wellbore.