Apparatus and method for sampling downhole fluids

Abstract

Tools and methods for downhole sample analysis are provided. An apparatus for sampling a downhole fluid includes a tool having at least one surface element wetted by a downhole fluid such as drilling fluid, return fluid or production fluids such as asphaltenic hydrocarbons. At least one surface element disposed on the tool can include a fluid-repellent material disposed on a substrate for repelling at least a portion of the downhole fluid wetting the surface element.

1 . An apparatus for sampling a downhole fluid comprising:
 a tool having at least one surface element wetted by a downhole fluid, the at least one surface element including a fluid-repellant material disposed on a substrate for repelling some or all of the downhole fluid wetting the at least one surface element.   
   
   
       2 . The apparatus of  claim 1 , wherein the tool is wetted by the downhole fluid while deployed downhole via wireline or while drilling. 
   
   
       3 . The apparatus of  claim 1 , wherein the tool is wetted by the downhole fluid while deployed in a surface location. 
   
   
       4 . The apparatus of  claim 1 , further comprising one or more fluid test instruments having one or more surface elements. 
   
   
       5 . The apparatus of  claim 4 , wherein the tool includes one or more sensors exposed to the downhole fluid. 
   
   
       6 . The apparatus of  claim 5 , wherein the one or more sensors comprise one or more pressure sensors, temperature sensors, viscosity sensors, density sensors, optical sensors, fluorescence sensors, and flow rate sensors. 
   
   
       7 . The apparatus of  claim 1 , wherein the tool comprises a wavelength spectrum light generator and the fluid-repellant material is transparent to at least a portion of the wavelength spectrum generated by the wavelength spectrum light generator. 
   
   
       8 . The apparatus of  claim 1 , wherein the downhole fluid comprises one or more of a drilling fluid, a return fluid, and a formation fluid. 
   
   
       9 . The apparatus of  claim 1 , wherein the downhole fluid comprises hydrocarbons having twenty or more carbon atoms per molecule. 
   
   
       10 . The apparatus of  claim 1 , wherein the downhole fluid comprises one or more of a polar fluid, and non-polar fluid. 
   
   
       11 . The apparatus of  claim 1 , wherein the fluid-repellent material comprises one or more of polytetrafluoroethylene (PTFE) compounds, fluorocarbon resins, fluoropolymers, silicone polymers, and fluorocarbon polymers. 
   
   
       12 . The apparatus of  claim 1 , wherein the fluid-repellent material comprises a coating applied to the substrate by one or more of powder coating, spraying, immersion, and electrostatic deposition. 
   
   
       13 . A method for sampling a downhole fluid comprising:
 wetting at least one surface element of a tool with a downhole fluid the at least one surface element comprising a fluid-repellant material disposed on a substrate; and   repelling some or all of the downhole fluid from the at least one surface element.   
   
   
       14 . The method of  claim 13 , wherein the wetting of the surface element with the downhole fluid occurs while the tool is deployed downhole via wireline or a drilling sub. 
   
   
       15 . The method of  claim 13 , wherein wetting the at least one surface element occurs while the tool is deployed in a surface location. 
   
   
       16 . The method of  claim 13 , wherein of a drilling fluid, a return fluid, and a formation fluid. 
   
   
       17 . The method of  claim 13 , wherein wetting the at least one surface element includes wetting with one or more hydrocarbons having twenty or more carbon atoms per molecule. 
   
   
       18 . The method of  claim 13 , wherein wetting the at least one surface element includes wetting with one or more polar fluids, and one or more non-polar fluids. 
   
   
       19 . The method of  claim 13 , wherein the fluid-repellent material comprises one or more of polytetrafluoroethylene (PTFE) compounds, fluorocarbon resins, fluoropolymers, silicone polymers, and fluorocarbon polymers. 
   
   
       20 . The method of  claim 13 , wherein the fluid-repellent material comprises a coating applied to the substrate by one or more of powder coating, spraying, immersion, and electrostatic deposition. 
   
   
       21 . A method for manufacturing apparatus for sampling a downhole fluid comprising:
 disposing a fluid-repellant material on a substrate to form a surface element;   forming at least a portion of a downhole fluid sampling tool using the surface element, the surface element being wettable by a downhole fluid during operation of the downhole fluid sampling tool.   
   
   
       22 . The method of  claim 21 , wherein the fluid-repellent material comprises one or more of polytetrafluoroethylene (PTFE) compounds, fluorocarbon resins, fluoropolymers, silicone polymers, and fluorocarbon polymers. 
   
   
       23 . The method of  claim 21 , wherein the fluid-repellent material comprises a coating applied to the substrate by one or more of powder coating, spraying, immersion, and electrostatic deposition.