The disclosed subject matter is generally relates to mixing a first fluid with a second fluid in a subterranean environment. More particularly, the disclosed subject matter of this patent specification relates to mixing the first fluid such as a reagent fluid with the second fluid such as formation fluid, wherein at least embodiment includes the reagent fluid as a liquid and the formation fluid as a gas.
Mixing fluids with a reliable efficiency in downhole tools is an important process to manipulate downhole fluids, for example one of many purposes may include gas scrubbing and/or colorimetric sensing.
There is a need for an exact mixing volume between two components in a downhole mixing process. To date, there is no known downhole mixing process, however there are various downhole tools such as the MDT and the CHDT (trademarks of Schlumberger) tools that can be useful in obtaining and analyzing fluid samples. The downhole tools such as the MDT tool (see, e.g., U.S. Pat. No. 3,859,851 to Urbanosky, and U.S. Pat. No. 4,860,581 to Zimmerman et al., which are hereby incorporated by reference herein in their entireties) typically include a fluid entry port or tubular probe cooperatively arranged within wall-engaging packers for isolating the port or probe from the borehole fluids. It is noted they also include sample chambers which can be coupled to the fluid entry by a flow line having control valves arranged therein.
Therefore it is necessary to devise methods and devices to overcome at least the above discussed challenges and other technological challenges related to mixing fluids in a subterranean environment.
The present disclosed subject matter relates to a downhole apparatus for mixing a first fluid with a second fluid in a subterranean environment, the downhole apparatus includes a chamber having a first end, a second end and at least one opening, wherein the at least one opening allows fluid to flow there through. A perforated piston and at least one piston positioned within the chamber, each having a bottom surface and a top surface. Wherein the top surface of the perforated piston is capable of contacting the second end and the top surface of the at least one piston is capable of contacting the bottom surface of the perforated piston. One or more channel within the perforated piston allows for fluid to flow there through, and the perforated piston is located at a first position within the chamber based upon characteristics of a first fluid. A first fluid delivery system for supplying the maximum volume of the first fluid to the chamber, a second fluid delivery system for supplying a second fluid to the chamber, wherein the second fluid is at a pressure that moves the at least one piston approximate to the first end, the second fluid delivery system closes the at least one opening. Finally, an actuating device applies a force against the bottom surface of the at least one piston to inject the fluids through the one or more channel from the bottom surface through to the top surface of the perforated piston to produce spray droplets.
According to aspects of the subject matter disclosed, the characteristics of the second fluid can include a compressibility volume change of the second fluid and a volume of the first fluid flowing through the perforated piston. Further, the characteristics of the second fluid can provide for a maximum volume of the first fluid, the maximum volume of the first fluid is configured by a volume change upon compression of the second fluid such that at least approximately 15%, 20%, 25%, 30%, 35% or possibly within a range of 15% to 50% of the first fluid flows through the perforated piston. It is noted, the first fluid can be a reactant fluid including a neutralizing acid, a base or pH balancing agent, a salt containing at least one salt-out organic compound such as for removing water or some similar type of reactant fluid. Further still, the first fluid can be a reactant fluid, the reactant fluid may be from the group consisting of one of H2S detection, CO2 detection, Hg detection or one or more molecule of the second fluid. It is possible the second fluid is a formation fluid that can be one of a gas, a liquid or some combination thereof.
According to aspects of the subject matter disclosed, wherein producing the spray droplets is partially due to one of: the one or more channels of the perforated piston being one of linear, non-linear or both; or a mechanism incorporated into the perforated piston to increase friction in the chamber allowing for a higher spraying pressure. The one or more channels of the perforated piston can be two or more channels. Further, at least one channel of the two or more channels can be one of partially angled along the channel, include two or more outlets of the channel on the top surface of the perforated piston, include two or more inlets of the channel on the bottom surface of the perforated piston, include a larger diameter at an inlet of the channel on the bottom surface of the perforated piston than a outlet diameter of the channel on the top surface of the perforated piston, or some combination thereof. Further still, the second fluid delivery system can be in communication with a downhole tool having an inlet disposed on an exterior of the downhole tool for engaging a formation in the subterranean environment, the downhole tool can have a chamber fluidly connected to the inlet, so a test fluid may be disposed in the chamber, the chamber containing the test fluid is fluidly connected to the chamber wherein the test fluid is capable of being the second fluid. Wherein a mass of the sprayed fluid mixture can be in droplets. It is possible the sprayed fluid mixture can provide for one of: increasing a surface to volume ratio of the first fluid to significantly increase the contact area between the first and second fluid, so there is reaction or mixing with the second fluid; a manipulation of the fluid mixture properties such as one of a compound extraction; or a compound stripping of the second fluid by the first fluid. Further still, the downhole apparatus can be used for one of a gas scrubbing, a colorimetric sensing measurement, downhole measurements such as electrochemical sensing or magnetic resonance sensing. It is also possible, another application may include chemical treatment to improve sample conservation for sample analysis uphole.
According to aspects of the subject matter disclosed, the actuating device can apply multiple forces against the at least one piston, such as the force directing the at least one piston toward the second end and another force directing the at least one piston toward the first end. The mixing device can further comprise of a second piston of the at least one piston, the second piston can be capable of contacting the bottom surface of the piston and includes at least one magnet to identify a location of the at least one piston during the mixing of the first fluid with the second fluid. Further, the mixing device can further comprise of at least one sealing device for each of the perforated piston and the at least one piston, wherein the sealing device is from the group consisting of one of at least one o-ring or one or more elastomeric device.
According to aspects of the subject matter disclosed, the top surface of the at least one piston can be symmetrically formed to the bottom surface of the perforated piston. Further, the top surface of the at least one piston can be one of linear, non-linear, geometric shaped or some combination thereof. It is possible the top surface of the perforated piston may be symmetrically formed to the second end. Further, the top surface of the perforated piston can be one of linear, non-linear or some combination thereof so as to enhance one of a spraying effect or a fluid mixture flow exiting the chamber. It is noted that the chamber, the at least one piston or the perforated piston can include one or more coatings, such as at least one coating is capable for manipulation of the second fluid containing hydrogen sulfide (H2S). It is also possible the chamber, the at least one piston or the perforated piston be at least partially made of or include at least one coating having a material with material properties/characteristic that do not scavenge the analytes. For example, the material with material properties/characteristic may include: silicon, a processed/synthetic diamond, other inert materials, titanium, other metal alloys, glass, polymer-glass mixtures, carbon nanotube-polymer composites, polymer metal composites (such as an O-ring). Further, at least one spring device can be positioned between the top surface of the perforated piston and the second end of the chamber.
According to aspects of the subject matter disclosed, the at least one channel of the one or more channel can have a diameter in a range between 10 microns to 5 centimeters. Further, at least one channel of the one or more channel can have a diameter in a range between 0.2 millimeters to 1 millimeter. It is possible the top surface of the perforated piston can include at least one nozzle that is one of unitary or detachable extending away from the top surface of the perforated piston. It is possible the nozzle may be a telescoping nozzle extending away from the top surface when fully extended, having one or more outlets.
According to aspects of the subject matter disclosed, a length of the one or more channel is dependent on determining an amount of generated force by the resistance difference over a resistance that places the perforated piston in motion to a resistance (maximum static friction force) that keeps the perforated piston stationary, the generated force is less than a force required to move the perforated piston. For example, it is important that the perforated piston remains at the same position during mixing but can be moved after the mixing is completed. This can be achieved by the use of one or more O-rings. The maximum static friction force generated by the O-rings should therefore be higher than the force generated by the pressure difference over the perforated piston during compression and decompression.
The maximum static friction force is given by:
F
s,max=μsN
where:
Fs,max is the maximum static friction force
μs is the coefficient of static fraction
N is the normal force generated by the compression of the O-rings.
The force generated by the pressure difference over the perforated piston is given by:
F=Δp*A=Δp*πr
2
F is the force pushing the perforated piston
Δp is the pressure difference between top and bottom of the perforated piston
A is the surface area of the perforated piston
r is the radius of the perforated piston
Under the restriction of laminar flow, the pressure difference over the perforated piston is given by the Hagen-Poiseuille equation:
η is the viscosity of the reagent;
lc is the length of the channel;
Q is the volumetric flow rate; and
rc is the radius of the channel.
In accordance with another embodiment of the disclosed subject matter, a downhole method of mixing a first fluid with a pressurized second fluid by forming fluid droplets by spraying a pressurized fluid mixture. The method includes the steps of: (a) positioning a perforated piston having a top surface and a bottom surface within a chamber, wherein the perforated piston is located at a first position within the chamber based upon characteristics of a second fluid, the chamber having a first end, a second end and at least one opening; (b) introducing the first fluid into the chamber, wherein the perforated piston has one or more channel for fluid to flow there through; (c) introducing the pressurized second fluid into the chamber, the pressurized second fluid partially mixes with the first fluid, the fluid mixture flows through the one or more channel from the top surface and exits the bottom surface of the perforated piston to move at least one piston to approximately the first end of the chamber, closing the at least one opening; (d) actuating a bottom surface of the at least one piston with an actuating device to move the at least one piston from the first end toward the second end of the chamber to inject the fluid mixture through the one or more channel from the bottom surface through to the top surface of the perforated piston to produce spray droplets, wherein a top surface of the at least one piston is capable of contacting the bottom surface of the perforated piston; (e) actuating the bottom surface of the at least one piston with the actuating device to move the at least one piston from the second end to the first end of the chamber; (f) repeating steps (d) and (e) one or more times; and finally (g) opening the at least one opening, actuating the bottom surface of the at least one piston with the actuating device to move the at least one piston from the first end to the second end of the chamber to exit the fluid mixture out of the chamber, wherein the top surface of the at least one piston contacts the bottom surface of the perforated piston and the top surface of the perforated piston contacts the second end of the chamber.
Further, it is possible that when the fluid was introduced and partially mixes that the volume correction is not strictly needed. For example, entry of the second fluid can be controlled by pumping pump fluid out slowly. Pumping may add error on the actual amount of the second fluid which comes in if the second piston is very difficult to move. Further still, it may be more suitable for liquid-liquid mixing if the second fluid volume is defined and gas is added at a later time. Another possibility may allow for mixing if the entry of the second fluid was due to a high pressure of the second fluid. However, this may not be suitable for liquid-liquid mixing as the second fluid may fill the whole chamber, such that a volume correction may be required. Further, if there is no control of the fluid entry, then the volume error of the second fluid may be suppressed.
According to aspects of the subject matter disclosed, wherein step (g) further comprises a downhole tool for housing the chamber wherein the exiting fluid mixture is in communication via a fluid mixture flow line with at least one external detector located in the downhole tool. Wherein step (g) includes the first fluid and the second fluid exiting the chamber as a homogenous fluid. Further, the perforated piston can remain in the first position from step (b) through to step (f). It is also noted that the fluids may be transferred to another cylinder. The fluids that can be separated for example oil and water, can be respectively transferred to different locations.
According to aspects of the subject matter disclosed, the characteristics of the second fluid include a compressibility volume change of the second fluid and a volume of the first fluid flowing through the perforated piston. Further, the characteristics of the second fluid can provide for a maximum volume of the first fluid, the maximum volume of the first fluid is configured by a volume change upon compression of the second fluid such that at least 25% (or as noted above 15%, 20%, 25%, 30%, 35% or possibly a range of 15% to 50%) of the first fluid flows through the perforated piston. Wherein step (d) can include the first fluid is a reagent fluid and the second fluid is a formation fluid, and the creating of the spray droplets results in a larger surface for the reagent fluid to react with the formation fluid. Wherein step (d) can provide spray droplets that one of increases a surface to volume ratio of the first fluid to significantly increase reaction or mixing with the second fluid, manipulates the fluid mixture properties such as a compound extraction or a compound stripping of the second fluid by the first fluid. The method can include the second fluid being a formation fluid that is one of a gas, a liquid or some combination thereof. Wherein producing the spray droplets can be partially due to the one or more channels of the perforated piston being one of linear, non-linear or both. Further, wherein producing the spray droplets can be partially due to the one or more channels of the perforated piston being two or more channels. It is noted that producing the spray droplets or streams can be partially due to at least one channel of the two or more channels being one of partially angled along the channel, including two or more outlets of the channel on the top surface of the perforated piston, including two or more inlets of the channel on the bottom surface of the perforated piston, including a larger diameter at an inlet of the channel on the bottom surface of the perforated piston than a outlet diameter of the channel on the top surface of the perforated piston, or some combination thereof. It is possible the second fluid delivery system is in communication a downhole tool having an inlet disposed on an exterior of the downhole tool for engaging a formation in a subterranean environment, the downhole tool has a chamber fluidly connected to the inlet, so a test fluid is disposed in the chamber which is capable of being used as the second fluid. It is noted that producing the spray droplets can be assisted by the at least one piston and the perforated piston each having at least one sealing device, wherein the at least one sealing device is from the group consisting of one of at least one o-ring or one or more elastomeric device.
It is noted at least one portion of the first piston may be reshaped or designed to include: one or more void to reduce the weight (inertia) of the piston so as to maximize the friction (multiple O-ring). Further, the one or more voids may at the final step, allow for small amount of liquids to remain (or to be collected) for further analysis at surface so as to confirm reaction, mixing efficiency and/or other types of identifications.
According to aspects of the subject matter disclosed, the method can also include chamber, the at least one piston or the perforated piston that is coated with one or more coatings, such as at least one coating capable manipulating the second fluid containing hydrogen sulfide (H2S). It is possible the top surface of the at least one piston can be configured to symmetrically form to the bottom surface of the perforated piston. Further, the top surface of the at least one piston can be configured to be one of linear, non-linear, geometric shaped or some combination thereof. It is possible the top surface of the perforated piston can be configured to symmetrically form to the second end of the chamber. Further still, the top surface of the perforated piston can be one of linear, non-linear or some combination thereof, so as to enhance one of a spraying effect or an increased flowing effect of the fluid mixture exiting the chamber
Further features and advantages of the disclosed subject matter will become more readily apparent from the following detailed description when taken in conjunction with the accompanying Drawings.
The present disclosed subject matter is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present disclosed subject matter, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present disclosed subject matter only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present disclosed subject matter. In this regard, no attempt is made to show structural details of the present disclosed subject matter in more detail than is necessary for the fundamental understanding of the present disclosed subject matter, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present disclosed subject matter may be embodied in practice. Further, like reference numbers and designations in the various drawings indicated like elements.
The present disclosed subject matter relates to a downhole apparatus for mixing a first fluid with a second fluid in a subterranean environment, the downhole apparatus includes a chamber having a first end, a second end and at least one opening, wherein the at least one opening allows fluid to flow there through. A perforated piston and at least one piston positioned within the chamber, each having a bottom surface and a top surface. Wherein the top surface of the perforated piston is capable of contacting the second end and the top surface of the at least one piston is capable of contacting the bottom surface of the perforated piston. One or more channel within the perforated piston allows for fluid to flow there through, and the perforated piston is located at a first position within the chamber based upon characteristics of a first fluid. A first fluid delivery system for supplying the maximum volume of the first fluid to the chamber, a second fluid delivery system for supplying a second fluid to the chamber, wherein the second fluid is at a pressure that moves the at least one piston approximate to the first end. Finally, an actuating device applies a force against the bottom surface of the at least one piston to inject the fluids through the one or more channel from the bottom surface through to the top surface of the perforated piston to produce spray droplets.
Further, the subject matter disclosed relates to methods and devices (or apparatuses) mixing a first fluid such as a reagent fluid with a second fluid such as formation fluid in a downhole environment, wherein at least embodiment includes the reagent fluid as a liquid and the formation fluid as a gas. For example, the mixing process will likely be in a tool such as a downhole tool, but other possible devices may be considered. Further, the subject matter disclosed provides many advantages, by non-limiting example, an advantage of mixing downhole fluids effectively in downhole tools. Formation gas or formation liquid can be transferred in to a sample bottle (MPSR) in Schlumberger MRMS Module of the Modular Dynamics Tester (MDT) or other similar types of devices. Another possible advantage, among the many advantages, is that the methods and devices can improve the surface area available for mixing of two fluids (gas-liquid, liquid-liquid, liquid-gas) in a bottle. It is noted that a bottle can be considered a cavity, chamber or any device able to hold fluids.
Regarding the downhole tools and methods which expedite the sampling of formation hydrocarbons, the downhole tools, i.e., sampling tools, are utilized to carry downhole the mixing device(s) of the subject matter disclosed in this application. By way of example and not limitation, tools such as the previously described MDT tool of Schlumberger (see, e.g., previously incorporated U.S. Pat. No. 3,859,851 to Urbanosky, and U.S. Pat. No. 4,860,581 to Zimmerman et al.) with or without OFA, CFA or LFA module (see, e.g., previously incorporated U.S. Pat. No. 4,994,671 to Safinya et al., U.S. Pat. No. 5,266,800 to Mullin, U.S. Pat. No. 5,939,717 to Mullins), or the CHDT tool (see, e.g., previously incorporated “Formation Testing and Sampling through Casing”, Oilfield Review, Spring 2002) may be utilized. An example of a tool having the basic elements to implement the subject matter as disclosed in the application as seen in schematic in
The subject matter disclosed in the application discloses apparatuses and methods for mixing downhole fluids effectively in downhole tools. Formation gas or formation liquid can be transferred in to a sample bottle (MPSR) in Schlumberger MRMS Module of the Modular Dynamics Tester (MDT) as noted above. Further, the apparatuses and methods can improve the surface area available for mixing of two fluids (gas-liquid, liquid-liquid, liquid-gas) in the bottle. Once the formation fluid is captured, a regular piston will be moved to push another fluid through a second piston equipped with holes to create spray effect. Further still, by using the subject matter disclosed to create fluid spray, surface to volume ratio of one fluid to react or mix with another fluid can be significantly increased. This can improve reaction efficiency, reduce the operation time and increase mixing efficiency, among other improvements and advantages. Realtime downhole operations involving chemical reaction, fluid properties manipulation (viscosity, compound extraction), compound stripping can be enabled and can be enhanced by the disclosed subject matter in the application.
According to an aspect of the subject matter disclosed, it is possible for simultaneous fluid manipulations and mixing followed by storage or analysis to be done realtime in downhole. For example, this can be useful for improving analysis quality, providing separation, extraction, neutralization (protecting specific reagent/mechanical/sensory components from aggressive compounds/corrosion), avoiding cross contamination, false positive, etc. Further, it may also provide for increasing contact area between two different fluid components, for example gas and liquid by several magnitudes higher than simple compression-decompression cycles, reducing operation time and risk for component failures in downhole environment. Further still, this process will enable various fluid manipulations in a closed and/or a partially closed container, that may include reaction, separation, cleaning, extraction, techniques (which are mostly available on the surface and usually require manual operations), but this is for automated process in downhole environment.
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Assuming that the temperature is constant:
Z
1
P
1
V
1
=Z
2
P
2
V
2
With Z1, P1, V1, Z2, P2 and V2 being the compressibility factor, the pressure and volume of the compressible fluid before and after compression. The compressibility factor is a function of temperature, pressure and gas composition, and is used to modify the ideal gas law to account for the real gas behavior. The compressibility factor is the ratio of the volume actually occupied by a gas at given pressure and temperature to the volume, the gas would occupy at the same pressure and temperature if it behaved like an ideal gas. The expected volume change ΔV is then:
Still referring to
The maximum static friction force is given by:
F
s,max=μsN Eq. 3
where:
Fs,max is the maximum static friction force
μs is the coefficient of static fraction
N is the normal force generated by the compression of the O-rings.
The force generated by the pressure difference over the perforated piston is given by:
F=Δp*A=Δp*πr
2 Eq. 4
F is the force pushing the perforated piston
Δp is the pressure difference between top and bottom of the perforated piston
A is the surface area of the perforated piston
r is the radius of the perforated piston
Under the restriction of laminar flow, the pressure difference over the perforated piston is given by the Hagen-Poiseuille equation:
η is the viscosity of the reagent
lc is the length of the channel
Q is the volumetric flow rate
rc is the radius of the channel
It is noted that the pressure difference between the top and bottom of the perforated piston (dP) should be divided by number of channels in the perforated piston (110). Further, by reducing the number of channels, i.e., holes, can create a higher spray with longer exposure time. The mixing and spraying process can also be controlled by the use of the regular piston equipped with magnet, and the mixing can be further enhanced by some additional mechanical parts. Wherein the magnetic component may be positioned outside of the cylinder to interact with the magnetic component in one or both pistons. It is possible the increase/decrease in magnetic field relative to the sensor placed at the top and bottom of the cylinder can enable a qualitative indication of position changes of these pistons.
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This patent application is related to commonly owned United States patent applications: 1) U.S. Provisional Patent Application Ser. No. 61/422,637 (Attorney's Docket No. 60.1951) titled “CHEMICAL SCAVENGER FOR DOWNHOLE CHEMICAL ANALYSIS” by Jimmy Lawrence et al.; 2) U.S. patent application Ser. No. 12/966,451 (Attorney's Docket No, PTC 60.1845) titled “HYDROGEN SULFIDE (H2S) DETECTION USING FUNCTIONALIZED NANOPARTICLES” by Jimmy Lawrence et al.; 3) U.S. patent application Ser. No. 12/966,464 (Attorney's Docket No, PTC 60.1853) titled “A METHOD FOR MIXING FLUIDS DOWNHOLE” by Christopher Harrison et al.; 4) U.S. patent application Ser. No. ______ (Attorney Docket No. 60.1846) titled “ELECTROSTATICALLY STABILIZED METAL SULFIDE NANOPARTICLES FOR COLORIMETRIC MEASUREMENT OF HYDROGEN SULFIDE” by Ronald Van Hal et al., all of which are incorporated by reference in their entirety herein.