Apparatus and method for collecting a downhole fluid

Abstract

A method and apparatus for collecting a downhole fluid are disclosed. A method includes receiving a downhole fluid into a downhole sub from a first borehole wall portion adjacent a formation of interest and expelling at least a portion of the received downhole fluid from the downhole sub to a second borehole wall portion, wherein substantially all of the expelled downhole fluid enters the second borehole wall portion. An apparatus includes a downhole sub, a formation sampling member coupled to the downhole sub for collecting the downhole fluid from a first borehole wall portion adjacent a formation of interest, a sample expulsion member coupled to the downhole sub for expelling at least a portion of the collected downhole fluid from the downhole sub to a second borehole wall portion, wherein substantially all of the expelled downhole fluid enters the second borehole wall portion.

1 . A method for collecting a downhole fluid, the method comprising:
 receiving the downhole fluid into a downhole sub from a first borehole wall portion adjacent a formation of interest; and   expelling at least a portion of the received downhole fluid from the downhole sub to a second borehole wall portion, wherein substantially all of the expelled downhole fluid enters the second borehole wall portion.   
   
   
       2 . A method according to  claim 1 , wherein the first borehole wall portion includes an isolated zone sealed using one or more of expanding a packer to contact the borehole wall and extending a probe having a sealing pad to contact the borehole wall. 
   
   
       3 . A method according to  claim 1 , wherein the second borehole wall portion includes an isolated zone sealed using one or more of expanding a packer to contact the borehole wall and extending a probe having a sealing pad to contact the borehole wall. 
   
   
       4 . A method according to  claim 1 , wherein receiving the downhole fluid into a downhole sub includes using a pump to lower fluid pressure within the first flow path. 
   
   
       5 . A method according to  claim 1 , wherein expelling at least a portion of the received downhole fluid includes injecting the expelled downhole fluid into the formation of interest. 
   
   
       6 . A method according to  claim 1 , wherein expelling at least a portion of the received downhole fluid includes injecting the expelled downhole fluid into a formation that is proximate the formation of interest. 
   
   
       7 . A method according to  claim 1  further comprising estimating a property of the downhole fluid as the downhole fluid flows through the downhole sub. 
   
   
       8 . A method according to  claim 7 , wherein estimating a property of the downhole fluid includes estimating a contamination level. 
   
   
       9 . A method according to  claim 8 , wherein expelling at least a portion of the received downhole fluid includes expelling the received downhole fluid until the estimated contamination level reached a predetermined level of contamination. 
   
   
       10 . A method according to  claim 1  further comprising storing at least a portion of the received downhole fluid in a fluid sample container. 
   
   
       11 . A method for collecting a downhole fluid, the method comprising:
 conveying a downhole sub in a borehole, the downhole sub including a fluid sampling tool;   sealing a first borehole wall portion adjacent a formation of interest using a first seal coupled to the fluid sampling tool;   sealing a second borehole wall portion using a second seal coupled to the fluid sampling tool;   establishing a first fluid path with the first borehole wall portion and the tool;   establishing a second fluid path with the second borehole wall portion and the tool;   receiving the downhole fluid into the fluid sampling tool using the first fluid path;   flowing the received downhole fluid through the tool during a cleanup process;   estimating a fluid contamination level during the cleanup process;   expelling at least a portion of the received downhole fluid from the tool using the second fluid path during the cleanup process to remove some or all borehole contaminants from the received downhole fluid until fluid flowing through the tool is a substantially contamination free connate formation fluid; and   storing the substantially contamination free connate formation fluid in a fluid sample chamber.   
   
   
       12 . An apparatus for collecting a downhole fluid, the apparatus comprising:
 a downhole sub;   a formation sampling member coupled to the downhole sub for collecting the downhole fluid from a first borehole wall portion adjacent a formation of interest; and   a sample expulsion member coupled to the downhole sub for expelling at least a portion of the collected downhole fluid from the downhole sub to a second borehole wall portion, wherein substantially all of the expelled downhole fluid enters the second borehole wall portion.   
   
   
       13 . An apparatus according to  claim 12  further comprising one or more of a packer and a probe having a sealing pad to contact the borehole wall for isolating the first borehole wall portion. 
   
   
       14 . An apparatus according to  claim 12  further comprising one or more of a packer and a probe having a sealing pad to contact the borehole wall for isolating the second borehole wall portion. 
   
   
       15 . An apparatus according to  claim 12  further comprising a pump for flowing the downhole fluid through the downhole sub. 
   
   
       16 . An apparatus according to  claim 12 , wherein the sample expulsion member includes a port positioned for injecting the expelled downhole fluid into the formation of interest. 
   
   
       17 . An apparatus according to  claim 12 , wherein the sample expulsion member includes a port positioned for injecting the expelled downhole fluid into a formation that is proximate the formation of interest. 
   
   
       18 . An apparatus according to  claim 12  further comprising a fluid evaluation module for estimating a property of the downhole fluid as the downhole fluid flows through the downhole sub. 
   
   
       19 . An apparatus according to  claim 18 , wherein the fluid evaluation module is operable for estimating a contamination level of the downhole fluid. 
   
   
       20 . An apparatus according to  claim 12  further comprising a fluid sample container for storing at least a portion of the received downhole fluid.