APPARATUS AND METHOD FOR MIXING FLUIDS
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.
The present application claims the benefit of U.S. Provisional Application Ser. No. 61/868419 filed August 21, 2013, which application is incorporated herein, in its entirety, by reference.
TECHNICAL FIELDThis disclosure relates to mixing fluids and, more particularly, to an apparatus for mixing fluids.
BACKGROUNDMixing devices can be used to mix two different types of fluids together downhole within a wellbore tool. More specifically, a mixing device can be used to create a mixture between a reactant and a formation fluid. The reactant can be used to detect a particular chemical within the formation fluid. In one example, the reactant is a fluid that is selected to detect hydrogen sulfide (H2S) within the formation fluid by reacting with the hydrogen sulfide and producing a detectable optical characteristic. Accordingly, the mixing device can be used to generate a mixture by thoroughly mixing the reactant with the formation fluid. This mixture can then be analyzed optically to determine the presence of a particular chemical within the formation fluid. To facilitate this optical analysis, often the mixing device generates a homogenous mixture between the reactant and the formation fluid.
SUMMARYIllustrative embodiments of the present disclosure are directed to a wellbore tool for mixing a first fluid with a second fluid. The wellbore tool includes a chamber with a first end, a second end, a first opening at the first end, and a second opening at the second end. The tool also includes a piston positioned within the chamber. 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. The tool further includes a restrictor positioned at the first end of the chamber. The restrictor allows the flow of fluid through the first opening and into the chamber and partially restricts flow of fluid through the first opening and out the chamber. Furthermore, the tool also includes a perforated piston positioned within the chamber between the piston and the second end of the chamber. The perforated piston includes 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.
Various embodiments of the present disclosure are also directed to a downhole method for mixing a first fluid with a second fluid within a chamber. The chamber includes a piston, a perforated piston, a first end with a first opening, and a second end with a second opening. The method includes:
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- (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.
Further features and advantages will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings:
Illustrative embodiments of the present disclosure are directed to an apparatus for mixing a first fluid with a second fluid. The second fluid can be a formation fluid that includes a gas, a liquid, or both. The first fluid can be a reactant fluid that reacts when mixed with the formation fluid to detect presence of a particular chemical species within the formation fluid (e.g., hydrogen sulfide (H2S), carbon dioxide (CO2), and mercury (Hg)). The mixing apparatus described herein includes a restrictor that protects components of the mixing apparatus during operation. Details of various embodiments are described below.
The mixing apparatus 100 also includes a fluid delivery system for providing fluids to the chamber. In this embodiment, the fluid delivery system include a valve 120 in fluid communication with the second opening 110 and a pump 122 in fluid communication with the first opening 108. The fluid delivery system moves the piston 112 towards the first end 104 of the chamber 102 and thus supplies a volume of the second fluid to the chamber through the second opening. In some embodiments, the first fluid is pre-loaded within the chamber 102. In other embodiments, the fluid delivery system first introduces the first fluid into the chamber 102 and then introduces the second fluid. The fluid delivery system also moves the piston 112 towards the perforated piston 118 and the second end 106 of the chamber to inject at least a portion of the first fluid through the one or more channels of the perforated piston 118 and into the second fluid.
Movement of the piston 112 can be accomplished by using the pump 122 to introduce a third fluid (e.g., water) into the first end 104 of the chamber. The third fluid is used to hydraulically push on the piston 112 and move the piston towards the perforated piston 118 and the second end 106 of the chamber. Also, the piston 112 can move back towards the first end 104 of the chamber by removing the third fluid from the chamber 102 through the restrictor 114. The third fluid can be removed using the pump 122 or by opening a valve (not shown) that creates a pressure difference between the first end of the chamber 104 and the second end of the chamber 106. For this reason, the first end 104 of the chamber can be referred to as the “hydraulic end.”
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The processes in
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Illustrative embodiments of the present disclosure are directed to oilfield applications.
Operation of the fluid delivery system shown in
Once the formation fluid has been introduced, in.
In
The processes in
Once the mixing is complete, in
The restrictor 114 allows the piston 112 to descend in a controlled manner by restricting the rapid exit of the third fluid 304 from the chamber 102 through the first opening 108. Without the restrictor 114, when the first end 104 of the chamber is opened to the wellbore pressure, the pressure imbalance would force the third fluid 304 out of the chamber, thereby, forcibly impacting the piston 112 against the first end 104 of the chamber and also potentially shifting the position of the perforated piston 118 within the chamber. Damage to the piston 112 and/or movement of the perforated piston 118 may render the apparatus inoperable for subsequent mixing cycles.
The descent of the piston 112 can also be controlled by the pump 606. However, to repetitively perform the processes shown in
Further details regarding the chamber 102, the piston 112, the perforated piston 118, the fluid delivery system, the reactant fluids, and methods for mixing are described in U.S. Pat. No. 8,708,049, issued on Apr. 29, 2014, which is incorporated herein by reference in its entirety.
In various embodiments, the first fluid or the second fluid can be a liquid or a compressible fluid, such as a gas. The first fluid or the second fluid can be a sample fluid such as a formation fluid that is withdrawn from a subterranean formation. Also, the first fluid or the second fluid can be a reactant fluid. The reactant fluid can be used to detect various chemicals, such as hydrogen sulfide (H2S), carbon dioxide (CO2), and mercury (Hg) within another fluid. For example, the reactant fluid can use metal ions to react with a particular chemical within a sample fluid, such as a formation fluid. Further details regarding reactant fluids are provided in U.S. Patent Application Publication 2012/0276648, published on Nov. 1, 2012, and U.S. Patent Application Publication 2012/0149117, published Jun. 14, 2012. Both of these applications are hereby incorporated herein by reference in their entireties.
Illustrative embodiments of the present disclosure are not limited to wireline logging operations, such as the ones shown in
Although several example embodiments have been described above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the scope of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure.
Claims
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 H2S, CO2, 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.
Type: Application
Filed: Aug 21, 2014
Publication Date: Feb 26, 2015
Inventors: RONALD E. G. VAN HAL (BELMONT, MA), JAGDISH SHAH (CHESHIRE, CT), VICTORIA LEE (CAMBRIDGE, MA)
Application Number: 14/465,503
International Classification: E21B 49/08 (20060101);