Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to an inline system and method to separate a phases in a flowing fluid mixture. In particular, the present invention relates to automated inline separators using gravity and density differences to remove a phase either the top or bottom or both of a stagnation chamber. The present invention also relates to determining density of the fluid mixture in the pipeline by measurement of separated phases from the stagnation chamber.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
In the oil and gas industry, there are already conventional separator tank systems, which range from several gallons to several thousands of gallons in volume and store mixtures of oil, gas, water and other substances. The mixtures settle in the separator tank systems, such that phases stratify or separate by gravity or density. When sufficiently settled, a particular phase can be removed from the mixture. A conventional separator tank system for separating water and oil from a mixture comprises a tank body, an inlet for receiving the mixture, an interface detector, an outlet for oil, and an outlet for water. Vents to remove gas and coalesce are also in common usage.
There is a need for inline system for separation of phases, while the mixture is flowing. The conventional separator tank system requires the mixture to be delivered to the tank for settling. There is no flow, and the mixture stays stagnant. Pumps must move the mixture again after the settling and separation. Avoiding the stop in flow is an advantage of inline systems for separating phases from a mixture.
U.S. Patent Publication No. 2014/0008278 by Badr et al., published on Jan. 9, 2014, discloses an inline oil-water separator. The invention of this publication uses a small deep chamber with a depth of two diameters and a width of one diameter of the inline pipe member. There is a vortex and settling chamber, which uses density differences to select water from the mixture. A sensor detects when the water level is high enough, and opens a valve to remove the water from the settling chamber.
U.S. Pat. No. 7,516,794, issued to Gramme et al on Apr. 14, 2009, also describes an inline separator tank system. The invention includes a pipe section with specific flow path, which includes a major loop or bend with a radius greater than five times the pipe radius. A recess, preceding the bend, allows denser substances to settle and separate. For example, water can be a denser fluid in the mixture, which can be removed from the mixture at the recess.
In addition to gravity separation, there is separation by proportional composition. In treatment of oil and water mixtures, at any given point in the process cycle, the mixture is frequently processed, including initial separation and other treatments, resulting in an agitated mixture with small, semi-stable oil droplets, that are impractical to remove via gravity separation, as identified in “New Method for Improving Oil Droplet Growth for Separation Enhancement,” by Anne Finborud et al (Society of Petroleum Engineers, 1999). However, the relative proportion of these small droplets to the total oil flow remains relatively consistent so long as the process and oil source are not changed.
It is an object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture in a pipeline.
It is another object of the present invention to provide embodiments of a system and method for inline phase separation in a stagnation chamber in fluid connection with a pipe.
It is still another object of the present invention to provide embodiments of an inline stagnation chamber of a separator system with reduced turbulence.
It is still another object of the present invention to provide embodiments of an inline stagnation chamber sufficient time and volume for phase separation.
It is yet another object of the present invention to provide embodiments of an inline stagnation chamber with a configuration to decrease flow speed through the stagnation chamber.
It is yet another object of the present invention to provide embodiments of an inline stagnation chamber with a configuration to increase volume of the chamber as flow moves through the chamber.
It is yet another object of the present invention to provide embodiments of an inline stagnation chamber with a slanted surface for a rate of increase of chamber cross-section so as to avoid turbulence.
It is yet another object of the present invention to provide embodiments of an inline stagnation chamber with a curved surface for a rate of increase of chamber cross-section so as to avoid turbulence.
It is another object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture with a stagnation chamber and a transition chamber.
It is still another object of the present invention to provide embodiments of an inline stagnation chamber of a separator system with different flow characteristics in the stagnation chamber and the transition chamber.
It is yet another object of the present invention to provide embodiments of an inline stagnation chamber with a phase separation different from a phase separation in a transition chamber.
It is an object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture with attachments to affect flow characteristics, such as baffles, perforations, filters, and undulations.
It is an object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture with multiple phases, including but not limited to highly distinct phases, emulsions, and foams.
It is an object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture for detecting density.
It is another object of the present invention to provide embodiments of a system to detect parts per million (ppm) concentrations of components of the fluid mixture.
It is another object of the present invention to provide embodiments of a system and method for inline phase separation of a fluid mixture for detecting leaks in systems with positive pressure seals, including but not limited to systems in a gas sweetening process.
These and other objectives and advantages of the present invention will become apparent from a reading of the attached specification.
Embodiments of the present invention include systems for inline phase separation of a fluid mixture through a pipe in a pipeline. The system may also be used to detect density of the fluid mixture. The system includes a pipe and a stagnation chamber. The pipe can be in fluid connection to the pipeline, such as a bypass for the fluid mixture flowing through the pipeline. The pipe is formed by a pipe body with an inlet at one end and a first outlet at an opposite end. The pipe body sets a flow direction of the fluid mixture from the inlet to the first outlet. The pipe body has a pipe cross-section set by tubular walls of the pipe body. The flow speed of the fluid mixture through the pipe is related to the pipe cross-section of the pipe body.
The stagnation chamber is located between the inlet and the first outlet. The stagnation chamber includes a top panel, a first side panel, a second side panel and a bottom panel. The panels define a chamber cross-section, which is greater than the pipe cross-section at the inlet of the pipe body toward the first outlet. The chamber cross-section expands greater than the pipe cross-section so as to reduce flow speed from the inlet to the first outlet. In some embodiments, the bottom panel remains flush with the pipe body so that the inlet, bottom panel, and first outlet are aligned. The first side panel and the second side panel extend radially outward or orthogonally from the bottom panel and the flow direction. The top panel connects the first and second side panels as top edges of the side panels angle away from the bottom panel. There is a second outlet on the top panel, which is in fluid connection with the inlet and the first outlet through the stagnation chamber. A segment of slope of the top panel forms an angle relative to the bottom panel, corresponding to the rate of decrease in the flow speed. The portion of the fluid mixture flowing through the second outlet allows determination of the density of the fluid mixture in the pipeline.
Embodiments of the present invention include the chamber cross-section expanding greater than the pipe cross-section so as to reduce flow speed and to allow for separation of the fluid mixture into phases. The flow speed can be slowed so that the fluid mixture is generally stagnant to allow for the sedimentation of heavier particles on the bottom of the stagnation chamber and lighter particles near the top of the stagnation chamber. The chamber cross-section can be greater than the pipe cross-section so as to reduce flow speed in the stagnation chamber to almost full stagnation at the second outlet. In some embodiments, the chamber cross-section can increase to 200-300% larger than the pipe cross-section or 350-400% larger than the pipe cross-section at the second outlet of the stagnation chamber. The segment of slope of the top panel can be angled at least 45 degrees relative to the bottom panel or range between 45 to 80 degrees from the bottom panel, such that the rate of expansion of the chamber cross-section has reduced or at least minimal turbulence.
Other embodiments of the present invention can include a window opening in the first side panel for visual observation of the phase separation. Still other embodiments include a baffle mounted within the stagnation chamber. The baffle can have an undulating surface and a shape corresponding to a shape of the first and second side walls of the stagnation chamber. Alternate baffles may also have perforations or filter elements or both. The second outlet at the top panel of the stagnation chamber can also have either a valve, a flow meter, a sensor or any combination thereof. Other meters and sensors can also be in fluid connection with the stagnation chamber.
Some embodiments of the system can include a transition chamber between the inlet of the pipe body and the stagnation chamber. The transition chamber is a smaller version of the stagnation chamber with panels defining a transition cross-section greater than the pipe cross-section. The transition chamber can reduce flow speed from the pipeline first. The stagnation chamber further slows the fluid mixture for the phase separation. The turbulence can be more controlled in the stagnation chamber from the transition chamber. There can also be accessories in fluid connection with the transition chamber, such as a removal outlet in the bottom of the transition chamber so that the heaviest particles are more immediately removed from the slowed fluid mixture. A depth sensor may also be in fluid connection with the transition chamber. Various other accessories can be attached to measure and detect the separating fluid in the transition chamber.
a, 7b, 7c, 7d, and 7e are schematic views of embodiments of the system for inline phase separation, showing variations of baffles.
This embodiment of the system 10 includes a pipe 20 comprised of a pipe body 22 with an inlet 24 at one end and a first outlet 26 at an opposite end. The pipe body 22 has a flow direction 28 from the inlet 24 to the first outlet 26 and a pipe cross-section 30 set by walls 32 of the pipe body 22. The flow direction 28 can be aligned with the flow direction 3 in the pipeline 1 of
The present invention is a system 10 with a particular stagnation chamber 40 having a chamber cross-section 50 expanding greater than the pipe cross-section 30 so as to reduce flow speed in the stagnation chamber 40. In some embodiments, there can be almost full stagnation of the fluid mixture at the second outlet 52. The stagnation chamber 40 of the present invention can particularly defined by the chamber cross-section 50 having a cross-section 200-300% larger than the pipe cross-section 30. Alternatively, the chamber cross-section 50 can have an end cross-section 54 that is 350-400% larger than the pipe cross-section 30 at the second outlet 52. Also, the greatest height or distance of the stagnation chamber away from the pipe body and the height of the pipe body can be 2.5 times greater than the height of the pipe body.
Furthermore, the stagnation chamber 40 can be defined by the top panel 42 having a segment of slope 41 forming an angle of at least 45 degrees relative to the bottom panel 48. The first side panel 44 and the second panel 46 have angled edges matching the top panel 42 from the inlet 24 to the second outlet 52. Alternatively, the top panel 42 can have a segment of slope forming an angle between 45 to 80 degrees relative to the bottom panel 48. The rate of decrease in flow speed allows for separation of the phases of the fluid mixture with reduced turbulence. The embodiment of the present invention controls the increase in chamber cross-section 50. The panels 42, 44, 46, 48 define the particular stagnation chamber 40 for a sufficient rate of slowing of flow speed without undue turbulence, which would prevent the phase separation. The relationship between the top panel 42, bottom panel 48 and the pipe body 22 is an embodiment of the present invention for consistent and significant phase separation.
The present invention shows the effective separation as the consistent volume of a phase to be extracted from the stagnation chamber.
The dimensions of the stagnation chamber 40 are sufficient to settle phases in the fluid mixture by gravity, density or other separation means. The interior volume with the top panel 42 can be curved, slanted or a combination of surfaces. This embodiment of the stagnation chamber 40 is also compatible with the pre-existing technologies for phase separation and oil removal that are used to improve phase separation and oil removal, including: (1) mechanical, including kinetic manipulation, such as sonic agitators to accumulate larger oil particles, baffles, parallel plate and screen coalescers, or centrifuging; (2) thermal, primarily heating; (3) chemical additions to change surface tension and enhance separation; and (4) electrostatics, commonly used with desalters. The materials used may be modified for improved performance, for example surface treatments, for example hydrophobic or oleophobic coatings.
Embodiments of the system 10 can have various accessories.
The transition chamber 124 of
In some embodiments, the transition expanding portion 125 and transition set portion 127 can also be applied to the stagnation chamber 40 as an expanding portion and a set portion. The expanding portion is between the inlet and the set portion, and the set portion is between the expanding portion and the second outlet. The flow speed through the expanding portion decreases, but remains stable in the set portion. The set portion has a chamber cross-section greater than the pipe cross-section of the pipe body and the transition cross-section of the transition chamber. In still further embodiments, the order can be reversed, so that the set portion stabilizes flow speed before the lighter phases are separated at the second outlet. For example, there is less turbulence when the flow speed is no longer changing. The chamber cross-section expands along the top panel in different effective configurations for the effective separation supported in
The present invention can achieve inline separation for a fluid mixture with a quick separation of 95% of the oil/water mixture, but a somewhat slower separation for the remainder, or a fluid mixture with high or low water-cut, where the oil should be very dry. For example, in the case of 95% water-cut, the separator is targeting the 5% oil cut. The fluid mixture can be slowed so that the 5% of the oil can be occupied in the stagnant region of the tank, which could be 40% of the tank volume. Thus, the effective residence time is 0.4/0.05=8 times that of a traditional tank, and so a much smaller tank can be used.
The present invention can also function as a ppm meter, as shown in
The present invention provides embodiments of a system for inline phase separation of a fluid mixture with a stagnation chamber. The fluid mixture in a pipeline can be diverted to a pipe of the system of the present invention for phase separation and analysis, such as density detection. There is slower flow speed and reduced turbulence to allow for sufficient time and volume for an effective and consistent phase separation. The top panel, bottom panel, and pipe body control the rate of decrease of flow speed and separation time by increasing volume in relation to the pipe body as the fluid mixture flows further through the stagnation chamber. Various embodiments further control the effective separation with segments of slope for the rate of increasing cross-section and baffles to divert and lengthen flow paths. Some embodiments include a transition chamber with another set of top panels and bottom panels to insure the effective separation without undue turbulence in the stagnation chamber. There are differences in a phase separations in the transition chamber and the stagnation chamber, such that some heavy particles can be quickly removed from the transition chamber.
Embodiments also include accessories, such as baffles, perforations, filters, and undulations. These accessories can further control the flow speed and separation of phases. The duration in the stagnation chamber and lengthening of the flow path can refine the separation at the second outlet. Sensors, valves, and meters at the outlets further monitor the phase separation for the effective separation. The present invention shows the effective separation as the consistent volume of a phase to be extracted from the stagnation chamber. The fluid mixture with multiple phases can include highly distinct phases, emulsions, and foams. Use of the system is a method for inline phase separation of a fluid mixture for detecting density. The system can detect parts per million (ppm) concentrations of components of the fluid mixture. Additionally, the collected data at the outlets can be used to detect leaks in systems with positive pressure seals, including but not limited to systems in a gas sweetening process.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated structures, construction and method can be made without departing from the true spirit of the invention.
The present application claims priority under 35 U.S.C. Section 119(e) from U.S. Provisional Patent Application Ser. No. 62/036,710, filed on 13 Aug. 2014, entitled “SYSTEM AND METHOD FOR INLINE PHASE SEPARATION IN A MIXTURE”.
Number | Date | Country | |
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62036710 | Aug 2014 | US |