Device for sampling a pressurised fluid, equipped with means for increasing the volume of the sampling chamber

Abstract

A device for sampling a fluid, includes a sampling chamber including a first piston driven by the fluid, and an additional device configured to increase the volume of the sampling chamber. The sampling chamber serves as both a sampler and also as a container for the sampled fluid and it can also be used as a cell for the analysis of the fluid.

1 . A device for sampling at least one pressurized fluid, comprising at least one sampling chamber including an inner volume for receiving said fluid, said sampling chamber comprising a first piston capable of being displaced by said fluid, wherein the sampling chamber comprises an additional device configured to increase the volume of the sampling chamber. 
     
     
         2 . The device according to  claim 1 , wherein said sampling chamber is a container for transporting said fluid. 
     
     
         3 . The device according to  claim 1 , wherein said additional device configured to increase the volume of said sampling chamber comprises a compensation piston serving as a stop for said first piston and a system configured to adjust a position of said compensation piston. 
     
     
         4 . The device according to  claim 3 , wherein the a system configured to adjust the position of said compensation piston is a hydraulic system. 
     
     
         5 . The device according to  claim 3 , wherein said compensation piston has a stroke representing between 0.1 and 20% of the volume of the sampled fluid. 
     
     
         6 . The device according to  claim 1 , further comprising a lower chamber located below said sampling chamber, and, in a lower part of said sampling chamber, a fitting for releasably securing said sampling chamber to said lower chamber, said fitting having a system configured to pass fluid between said sampling chamber and said lower chamber. 
     
     
         7 . The device according to  claim 6 , wherein said additional device configured to increase the volume of said sampling chamber comprises a compensation piston serving as a stop for said first piston and a system configured to adjust a position of said compensation piston, and wherein the compensation piston slides within said fitting around an inner cylinder. 
     
     
         8 . The device according to  claim 1 , wherein said sampling device comprises a sampling actuation system for opening or closing said sampling chamber. 
     
     
         9 . The device according to  claim 8 , wherein said actuating system comprises a motor opening and closing said sampling chamber and an electronic or mechanical control system of said motor. 
     
     
         10 . The device according to  claim 9 , wherein said electronic control system comprises at least one of the following: a clock, communication system, a temperature sensor, a pressure sensor, a CCL sensor, a gamma ray sensor. 
     
     
         11 . The device according to  claim 8 , wherein said sampling chamber is fixed in a removable manner, below the actuating system. 
     
     
         12 . The device according to  claim 1 , wherein said sampling chamber comprises an upper valve for allowing or preventing the passage of fluid in said sampling chamber, said upper valve being disposed above the first piston. 
     
     
         13 . The device according to  claim 1 , wherein said sampling device comprises one to five sampling chambers. 
     
     
         14 . A method a for producing a sample of a fluid in an underground environment with a device according to  claim 1 , the method comprising:
 a) lowering the sampling device in said underground environment with the sampling chamber closed;   b) sampling fluid within the sampling chamber of the sampling device by opening the sampling chamber for a predetermined time;   c) drawing the sampling device to the surface with said sampling chamber closed;   d) recovering the closed sampling chamber.   
     
     
         15 . The method according to  claim 14 , wherein, said sampling chamber comprises a compensation piston serving as a stop for said first piston and a system configured to adjust the position of said compensation piston, the compensation piston is held, during fluid sampling, in an upper position, and the sampling chamber is, in the recovering step, displaced in a lower position by the compensation piston. 
     
     
         16 . The method according to  claim 14 , wherein the fluid is conveyed while being in the closed sampling chamber. 
     
     
         17 . The method according  claim 14 , further including a step of analyzing the fluid contained in the sampling chamber. 
     
     
         18 . The method according to  claim 17 , further including, before the analysis step, a step of conditioning said sampling chamber at the temperature and pressure conditions of the underground environment. 
     
     
         19 . The method according to  claim 14 , wherein the sample is taken for monitoring a CO 2  storage site, a site for exploring or exploiting conventional or unconventional hydrocarbons, or a geothermal site.