Apparatus and method for mixing fluids

Abstract

Apparatuses and methods for mixing a first fluid with a second fluid are described herein. One such apparatus includes a chamber that contains the first fluid and the second fluid. The apparatus also includes a piston that is positioned within the chamber and that is movable within the chamber. The piston can move back and forth to mix the first fluid and the second fluid together. The apparatus further includes a restrictor that provides for controlled movement of the piston and thus protects the piston and other components of the apparatus during operation.

We claim: 
     
         1 . A wellbore tool for mixing a first fluid with a second fluid, the wellbore tool comprising:
 a chamber having a first end, a second end, a first opening at the first end, and a second opening at the second end;   a piston positioned within the chamber, wherein the piston generates a seal between the first end and the second end of the chamber and is movable along the chamber towards the first end and towards the second end of the chamber;   a restrictor positioned at the first end of the chamber and configured (i) to allow the flow of fluid through the first opening and into the chamber and (ii) to partially restrict flow of fluid through the first opening and out the chamber; and   a perforated piston positioned within the chamber between the piston and the second end of the chamber, wherein the perforated piston comprises a bottom surface, a top surface, and one or more channels that allow fluid to flow between the top surface and the bottom surface of the perforated piston.   
     
     
         2 . The wellbore tool of  claim 1 , the first fluid is pre-loaded within the chamber. 
     
     
         3 . The wellbore tool of  claim 1 , further comprising:
 a fluid delivery system configured (i) to move the piston toward the first end of the chamber in order to supply a volume of the second fluid to the chamber through the second opening and (ii) to move the piston towards the perforated piston and the second end of the chamber to inject at least a portion of the first fluid through the one or more channels of the perforated piston and into the second fluid.   
     
     
         4 . The wellbore tool of  claim 1 , wherein the second fluid is compressible. 
     
     
         5 . The wellbore tool of  claim 1 , wherein the second fluid is a formation fluid that comprises a gas, a liquid, or some combination thereof 
     
     
         6 . The wellbore tool of  claim 1 , wherein the first fluid is a reactant fluid. 
     
     
         7 . The wellbore tool of  claim 6 , wherein the reactant fluid is detects at least one of H 2 S, CO 2 , and Hg within the second fluid. 
     
     
         8 . The wellbore tool of  claim 1 , wherein the second fluid is a formation fluid and the wellbore tool further comprises:
 a fluid admitting assembly for extending into a formation and withdrawing the formation fluid from the formation and into the wellbore tool.   
     
     
         9 . The wellbore tool of  claim 1 , further comprising:
 a fluid analyzer configured to analyze a mixture of the first fluid and the second fluid.   
     
     
         10 . A downhole method for mixing a first fluid with a second fluid within a chamber that comprises a piston, a perforated piston, a first end with a first opening, and a second end with a second opening, the method comprising:
 (a) introducing the second fluid into the chamber;   (b) introducing a third fluid into the first end of the chamber through the first opening to move the piston towards the perforated piston and the second end of the chamber so that the piston injects at least a portion of the first fluid through the one or more channels of the perforated piston and into the second fluid;   (c) removing the third fluid through the first opening using a restrictor that partially restricts the flow of the third fluid through the first opening to move the piston away from the perforated piston and towards the first end of the chamber; and   (d) repeating processes (b) and (c) one or more times to form a mixture between the first fluid and the second fluid.   
     
     
         11 . The downhole method of  claim 10 , further comprising:
 (e) moving the piston toward the second end of the chamber so that the fluid mixture exits the chamber through the second opening.   
     
     
         12 . The downhole method of  claim 10 , wherein the perforated piston remains stationary during process (a) through process (d). 
     
     
         13 . The downhole method of  claim 10 , wherein the first fluid is a recant fluid and the second fluid is a formation fluid. 
     
     
         14 . The downhole method of  claim 10 , wherein, at process (b), a spray of droplets is formed when the first fluid is injected into the second fluid. 
     
     
         15 . The downhole method of  claim 10 , wherein the second fluid is a formation fluid that comprises a gas, a liquid, or some combination thereof 
     
     
         16 . The downhole method of  claim 10 , the first fluid is pre-loaded within the chamber. 
     
     
         17 . The downhole method of  claim 10 , wherein process (a) through process (d) are performed within a wellbore tool. 
     
     
         18 . The downhole method of  claim 17 , further comprising:
 withdrawing the formation fluid from a formation and into the wellbore tool.