Patent Document

FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to the separation of components in a multi-phase flow stream. More specifically, it relates to restructuring flow regimes by a flow shaping apparatus so that the majority of a particular fluid component in a flow stream is located in a certain area of the flow stream, which allows for effective separation of the various fluid components. 
       BACKGROUND OF THE INVENTION 
       [0002]    A gas-liquid two phase flow stream includes a mixture of different fluids having different phases, such as air and water, steam and water, or oil and natural gas. Moreover, the liquid phase of a fluid flow stream may further comprise different liquid components, such as oil and water. A gas-liquid two phase flow takes many different forms and may be classified into various types of gas distribution within the liquid. These classifications are commonly called flow regimes or flow patterns and are illustrated in  FIGS. 1A-1E . Bubble flow as illustrated in  FIG. 1A  is typically a continuous distribution of liquid with a fairly even dispersion of bubbles in the liquid. Slug or plug flow as illustrated in  FIG. 1B  is a transition from bubble flow where the bubbles have coalesced into larger bubbles with a size approaching the diameter of the tube. Churn flow as illustrated in  FIG. 1C  is a pattern where the slug flow bubbles have connected to one another. In annular flow as illustrated in  FIG. 1D , liquid flows on the wall of the tube as a film and the gas flows along the center of the tube. Finally, in wispy annular flow as illustrated in  FIG. 1E , as the liquid flow rate is increased, the concentration of drops in the gas core increases, leading to the formation of large lumps or streaks of liquid. 
         [0003]    It is often desirable to separate the gas and liquid components of a fluid from one another to enable proper operation of systems, such as certain types of liquid pumps. Conventional vertical or horizontal gas-liquid separators are available to separate gas from liquid. Conventional separators typically employ mechanical structures, wherein an incoming fluid strikes a diverting baffle which initiates primary separation between the gas and liquid components. Mesh pads or demister pads are then used to further remove suspended liquid. The sizing of a separator and the particular characteristics of the separator is dependent upon many factors, which may include, the flow rate of the liquid, the liquid density, the vapor density, the vapor velocity, and inlet pressure. Vertical separators are typically selected when the vapor/liquid ratio is high or the total flow rate is low. Horizontal separators are typically preferred for low vapor/liquid ratio or for large volumes of total fluid. 
         [0004]    One application of these types of separators is in oil and gas drilling operations. Specifically, a mud-gas separator is used when a kick is experienced in a wellbore during drilling operations. A kick is the flow of formation fluids into the wellbore during drilling operations. If a kick is not quickly controlled, it can lead to a blow out. As part of the process for controlling a kick, the blow-out preventors are activated to close the wellbore and wellbore fluids are slowly circulated out of the wellbore while heavier drilling fluids are pumped into the wellbore. A mud gas separator is used to separate natural gas from drilling fluid as the wellbore fluid is circulated out of the wellbore. Often times, however, prior art separators, have limited capability to process flow streams with high volumes and/or high flow rates, such as those characteristic of wellbores. 
         [0005]    Of course, separators are also used in the production of oil and gas to separate natural gas from oil that is being produced. Additionally, there are many other applications that require the use of gas-liquid separators. For example, when supplying fuel to ships, known as bunkering, air is often entrained in the fuel, causing an inaccurate measurement of the transferred fuel. Likewise, in oil production or production of other liquids, transferring or conveying a liquid may result in the liquid acquiring entrained gas during that process, a result observed in pipelines with altered terrains. In this regard, entrained gasses can prevent the accurate measurement of a liquid product, whether it is fuel transferred during bunkering or a liquid flowing in a pipeline. 
       SUMMARY OF THE INVENTION 
       [0006]    One aspect of the invention relates to shaping multi-phase mixed flow using a curvilinear flow line formed in multiple loops or coils prior to separation of a fluid component from the flow path. Shaping the multi-phase flow into a curvilinear path will allow centrifugal force to more readily force the heavier, denser liquid to the outside or outer diameter wall of the flow shaping line in the curved path and allow the lighter, less dense vapor or gas to flow along the inside or inner diameter wall of the flow shaping line. In certain embodiments, once a flow regime has been restructured within the flow line, the flow component collected adjacent a particular wall of the line can be removed. For example, in flow streams characterized by a larger liquid component, the gas component of a liquid-gas flow stream will collect along the inner diameter wall of the curved flow shaping line, where the gas can be drawn or driven into an exit port located on the inner wall, thereby permitting a majority, if not all, of the gas, along with a low amount of liquid, to be sent to a conventional gas-liquid separator. The separated fluid will have a comparatively higher ratio of gas to liquid than the primary flow stream in the flow line, but will pass into the conventional gas separator at a flow rate much lower than the total flow rate within the flow shaping line. This permits for efficient separation of the gas from the liquid with the use of a smaller, more economical conventional gas-liquid separator than what would have been required for the full flow stream and/or higher flow rates. 
         [0007]    In certain embodiments, a curvilinear flow line, whether in the form of a single loop or multiple loops, may be utilized in conjunction with a sensor for controlling an adjustable valve. In each case of multiple loops, the loops in the flow line permit an extended residence time of a flow stream through the system. A sensor disposed along the flow path is utilized to estimate a property of the flow  12 , such as for example, the percentage or “cut” of one or more components of the flow steam. The adjustable valve is positioned sufficiently downstream so that the valve can be timely adjusted based on the measurement from the sensor. For example, a sensor measuring cut can be utilized to adjust the position of a weir plate in the flow stream, thereby increasing or decreasing the amount of fluid separated from the flow stream. Although the sensors as described herein will be primarily described as measuring the cut, other types of sensors may also be utilized. Likewise, the type of cut sensors are not limited to a particular type, but may include the non-limiting examples of interface meters; optics or capacitance sensors. The extended residence time of the flow stream in the multi-loop system permits the valve to be adjusted once the cut is determined, thereby enhancing separation of fluid components once the flow stream has been restructured in accordance with the invention. The adjustable valve may be, for example, be a weir plate, foil or similar structure that can be used to draw off or separate one component of the flow stream. Other types of adjustable valves may also be utilized. 
         [0008]    In certain embodiments of a multi-loop system, the primary diameter of one or more loops or coils generally disposed along an axis may be altered along the length of the axis to control the flow rate through the system. In certain embodiments, the flow line will include a plurality of loops formed along an axis, with each successive loop having a smaller primary diameter than the preceding loop, such that the velocity of the flow stream within the flow line increases along the axis while maintaining flow regime separation. Likewise, in certain embodiments, the flow line will include a plurality of loops formed along an axis, with each successive loop having a larger primary diameter than the preceding loop, such that the velocity of the flow stream within the flow line decreases along the axis. 
         [0009]    In certain embodiments of a multi-loop system, two sets of loops or coils may be utilized along a flow path. The first set of loops will function to separate a component, such as gas, as described above. The second set of loops functions to address any gas that remains in the flow stream. In certain embodiments, prior to introduction of the flow stream into the second set of loops, the flow stream may be agitated so as to thereafter enhance flow regime reshaping as described above. 
         [0010]    Additionally, a fluid guiding surface may be placed on the inner wall of the flow shaping line at the exit port to further aid in directing the gas to flow to the conventional gas separator. 
         [0011]    Furthermore, the liquid return from the conventional gas-liquid separator may be arranged in close downstream proximity to the exit port on the inner wall of the flow shaping line. The close proximity of the liquid return and the exit port allows the use of a venturi, nozzle or other restriction located adjacent the liquid return in the flow shaping line just downstream of the exit port. The venturi, nozzle or other restriction accelerates the velocity of the liquid in flow shaping line as it flows across the exit port. This acceleration of the liquid helps to pull the liquid out of the conventional gas-liquid separator. In addition, the acceleration of the liquid within the flow shaping line helps to prevent any solids that may be present in the gas-liquid flow from entering the exit port and it helps to lower the amount of liquid that enters the exit port and thus enters the conventional separator. 
         [0012]    In certain embodiments, a heater may be disposed along a flow stream prior to flow regime reshaping in order to cause a phase change of at least a portion of the fluid within the flow stream. For example, certain liquid hydrocarbons in flow stream may be converted to gas under an applied heat in order to enhance separation of the hydrocarbon from the flow steam as described above. Such a heater may be utilized with curvilinear flow line having either single and multi-loops. 
         [0013]    Likewise, in certain embodiments, a curvilinear flow line having either single and multi-loops may be utilized in conjunction with a liquid-liquid phase separator. The liquid-liquid phase separator is preferably deployed down stream of the exit port and is disposed to separate different density liquids from one another. In certain embodiments, the liquid-liquid phase separator may be adjustable and utilized in conjunction with a sensor. The sensor is disposed along the flow path downstream of the gas exit port and is utilized to estimate the percentage or “cut” of various liquids remaining in the flow steam. The phase separator can be adjusted based on the cut. The phase separator may include, for example, an adjustable weir plate, adjustable foil, adjustable valve or similar adjustable mechanism. In one embodiment, the phase separator may include an adjustable valve in the form of rotatable ball having two flow passages therethrough. Rotation of the ball adjust the positions of the flow passages relative to the liquid-liquid flow stream, exposing more or less of a particular passage to the flow steam. Other types of adjustable valves may also be utilized. 
         [0014]    In another embodiment of the invention particularly suited for flow streams with a high gas content, i.e., “wet gas”, a flow channel is formed along at least a portion of the inner diameter wall of a curvilinear flow line as described herein. The liquid within the wet gas will collect in the flow channel and can be drained off from the primary flow stream. 
         [0015]    In another embodiment of the invention, the gas-liquid separator includes a variable position gas control valve that maintains level control of a vessel and establishes a constant flow pressure throughout the system. 
         [0016]    The invention therefore allows a multi-phase fluid to be effectively separated with the use of a smaller conventional separator than was previously possible. The invention accomplishes this without using additional complex mechanical devices and thus will operate efficiently and reliably. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    A more complete understanding of the present disclosure and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying figures, wherein: 
           [0018]      FIGS. 1A-1E  illustrate a cross-sectional view of various flow regimes of two phase gas-liquid flow. 
           [0019]      FIG. 2  illustrates a cross-sectional view of an embodiment of separation apparatus with a flow regime modification loop/coil and a liquid-liquid phase splitter. 
           [0020]      FIG. 3  illustrates an elevation view of the embodiment of the separation apparatus with a plurality of flow regime modification loops/coils of descending cross-sectional diameter. 
           [0021]      FIG. 4  illustrates an elevation view of the embodiment of the separation apparatus with a plurality of flow regime modification loops/coils having successively decreasing diameters and a liquid-liquid phase separator. 
           [0022]      FIG. 5  illustrates an elevation view of the embodiment of the separation apparatus with a plurality of flow regime modification loops/coils having substantially the same diameters and a liquid-liquid phase separator. 
           [0023]      FIG. 6   a  illustrates an elevation view of the embodiment of the separation apparatus with two sets of flow regime modification loops/coils of  FIG. 4 . 
           [0024]      FIG. 6   b  illustrates an elevation view of the embodiment of the separation apparatus with two sets of flow regime modification loops/coils of  FIG. 5 . 
           [0025]      FIG. 7  is an elevation view of a multi-phase flow separation apparatus utilizing two sets of loops/coils of  FIG. 4 , arranged in series. 
           [0026]      FIG. 8  illustrates a cross-sectional view of a flow regime modification loop/coil for wet gas processing. 
           [0027]      FIG. 9  illustrates a cross-sectional view of another embodiment of a liquid-liquid phase splitter with an adjustable valve. 
           [0028]      FIG. 10  illustrates a cross-sectional view of a gas control valve in a gas separation tank. 
           [0029]      FIG. 11  illustrates an elevation view of another embodiment of separation apparatus deployed in oil and gas drilling operations. 
           [0030]      FIG. 12  illustrates an elevation view of another embodiment of separation apparatus deployed in fuel bunkering operations. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    In the detailed description of the invention, like numerals are employed to designate like parts throughout. Various items of equipment, such as pipes, valves, pumps, fasteners, fittings, etc., may be omitted to simplify the description. However, those skilled in the art will realize that such conventional equipment can be employed as desired. 
         [0032]      FIG. 2  illustrates a cross-sectional view of an embodiment of a separation apparatus  10 . In an exemplary embodiment, the separation apparatus  10  is in fluid communication with a main flow line  15  in which a multi-phase flow  12  is traveling. The multi-phase flow  12  could be any type of multiphase gas-liquid flow regime or flow pattern, such as, for example, bubble flow, slug or plug flow, churn flow, annular flow or wispy annular flow. Moreover, the multi-phase flow may include two components within a single phase, such as water and oil within the liquid phase. The multi-phase flow  12  within main line  15  is directed into a curvilinear flow path  16  in a flow shaping line  17 . In certain embodiments, such as is illustrated in  FIG. 2 , the curvilinear flow path  16  is substantially in the form of a loop having a circular shape, although the curvilinear flow path may have other curvilinear shapes. In any event, the curvilinear flow path  16  of flow shaping line  17  creates an increased distribution of a first phase  22 , such as gas, along the inner wall  24  of the flow shaping line  17 . The increased distribution of this first phase  22  along the inner wall  24  of the flow shaping line  17  results in part by the relatively heavier and denser second phase  18 , such as a liquid, of flow  12  being forced to the outer wall  20  of the flow shaping line  17  due to centrifugal force of curvilinear flow path  16 , while the lighter first phase  22  is driven to the inner wall  24 . The flow shaping line  17  may be disposed in any orientation, including substantially in a vertical plane or a horizontal plane. In embodiments with a vertical or partly vertical orientation of the flow shaping line  17 , gravitational effects may also aid in increasing the distribution of the first phase  22  on the inner wall  24  of the flow shaping line  17 . 
         [0033]    As the multi-phase flow  12  continues to travel through the curvilinear flow path  16  of flow shaping line  17 , the multi-phase flow  12  forms a flow path that exhibits a high concentration of gas  22  along the inner wall  24  of the flow shaping line  17 . In the embodiment shown in  FIG. 2 , at location  26 , which is approximately 315 degrees around shaping line  17  (or 45 degrees from the vertical), the separation of gas  22  from liquid  18  has reached a degree that gas  22  primarily occupies the space adjacent the inner wall  24  of the flow shaping line  17 . As seen in  FIG. 3 , which is a cross section  3 - 3  of the flow shaping line  17  and multi-phase flow  12  at location  26 , the gas  22  occupies mainly the inner wall  24  of the circular flow path  16  of the flow shaping line  17  while the liquid  18  primarily travels along the outer wall  20 . 
         [0034]    With gas-liquid flow  12  forming a more stratified flow regime, or at least the distribution or volume of gas near the inner wall  24  of the flow shaping line  17  has increased at the point of location  26 , the gas  22  may be effectively bled off from the gas-liquid flow  12  at an outlet port  28  positioned along the inner wall  24  of the flow shaping line  17 , preferably along a curvilinear portion of flow shaping line  17 . In this regard, although outlet port  28  may be positioned anywhere along flow path  16 , it is preferably selected to be at a point where substantial separation of gas from liquid has occurred. Thus, in one preferred embodiment, the outlet port  28  is downstream of location  26 . At about a location  26 , which is approximately at an angle of approximately 45 degrees from a vertical axis  74  or otherwise, approximately 315 degrees about a circular flow path, it has been found that the concentration, separation or stratification of the gas  22  from the liquid  18  is at a point that gas  22  occupies a greater volume of space adjacent the inner wall  24  of the main line  15  than liquid  18 . In other embodiments, the outlet port  28  may be located between generally 45 degrees from the vertical and generally zero degrees with the vertical. While location  26  is illustrated at approximately 315 degrees around flow shaping line  17  and has been found to be a point where a substantial volume of gas has been driven to inner wall  24 , location  26  is used for illustrative purposes only. In this regard, in configurations with multiple loops formed by flow shaping line  17 , the outlet port  28  may be disposed along an inner wall of any one of the loops, including the first loop, the last loop or an intermediate loop. 
         [0035]    In an exemplary embodiment, a fluid guiding surface  30  is located at the outlet port  28 . In certain embodiments, a fluid guiding surface  30   a  may be located on the inside diameter  32  of the inner wall  24  of the flow shaping line  17  upstream of the outlet port  28 . The fluid guiding surface  30  includes a downstream end  36  that curves around the corner  37  located at the junction of the outlet port  28  and the flow shaping line  17 . The gas  22  follows the contour of the fluid guiding surface  30   a  and the gas  22  will follow the curve of the downstream end  36  into the outlet port  28 . In another embodiment, a fluid guiding surface  30   b  may comprise a weir plate, foil or similar separation mechanism disposed to direct gas  22  into outlet port  28 . The fluid guiding surface  30   b  functions to guide the gas  22  into the outlet port  28 . In certain embodiments, fluid guiding surface  30   b  is adjustable in order to adjust the position of fluid guiding surface  30   b , and hence, the first phase cut removed from flow stream  12 . A sensor  34  may be disposed to operate in conjunction with and control adjustable fluid guiding surface  30   b  based on a measured property of the flow stream  12 , such as cut. Although sensor  34  may be located anywhere along main line  15  or flow shaping line  17 , it has been found that sensor  34  is preferably separated a sufficient distance from outlet port  28  to permit the position of adjustable fluid guiding surface  30   b  to be adjusted once the cut of flow  12  has been determined. Likewise, in certain embodiments, sensor  34  is disposed along flow shaping line  17  at a point where substantial phase separation has taken place, such as at  26 , thereby increasing the accuracy of sensor  34 . 
         [0036]    An amount of liquid  18 ′ from the gas-liquid flow  12  will also be carried into the outlet port  28  thus forming a new gas-liquid flow  40  which includes a much lower percentage of liquid  18 ′ compared to the liquid  18  in gas-liquid flow  12 . The new gas-liquid flow  40  from outlet port  28  is then directed into a conventional gas-liquid separator  38 , as shown in  FIG. 2 , for further separation of the gas and liquid. Outlet port  28  is connected to the conventional gas-liquid separator by separator inlet line  33 . The gas-liquid separator  38  contains a gas exit  39  to permit removal of gas  22  separated from flow stream  12 . The gas-liquid separator  38  also contains a liquid exit  41 . In certain embodiments, liquid exit  41  that may be in fluid communication, via a line  44 , with flow shaping line  17  or a subsequent flow line  43  disposed at the end of the flow shaping line  17 . Those skilled in the art will appreciate that separation apparatus  10  is shown as integrated with gas liquid separator  38 , but can be a completely separate structure. 
         [0037]    In an exemplary embodiment, the liquid inlet port  42  is in close downstream proximity to outlet port  28  with a venture or similar restriction  46  formed therebetween along the flow path of liquid  18  flow. The restriction  46  accelerates the velocity of the liquid  18  as it flows across the liquid inlet port  42 . This acceleration of liquid  18  lowers the pressure of the liquid  18  flow in the primary flow path below that of the liquid  18 ′ in line  44 , thereby drawing liquid  18 ′ out of the conventional gas-liquid separator  38 . In addition, the acceleration of the liquid  18  facilitates separation of gas from liquid within flow shaping line  17 , minimizes the likelihood that any solids present in the gas-liquid flow  12  will enter outlet port  28 , and minimizes the amount of liquid  18  that enters the outlet port  28 . 
         [0038]    In certain preferred embodiments, venturi  46  is adjustable, permitting the velocity of the flow therethrough, and hence the pressure drop across the venturi  46 , to be adjusted in order to control the amount of liquid  18 ′ drawn from conventional gas-liquid separator  38 . This in turn, permits the pressure of the gas within gas-liquid separator  38 , as well as the proportional amounts of liquid and gas therein, to be controlled. This is particularly desirable when gas void fraction to liquid is a higher percentile. To eliminate bypass of gas that might pass extraction point  28 . 
         [0039]    As mentioned above, the efficient first step in the separation of the gas  22  from the liquid  18  significantly decreases the amount of liquid  18  entering the conventional gas-liquid separator  38 . This allows for the use of much smaller size conventional gas-liquid separators than would have previously been possible for a given flow rate and/or flow volume. 
         [0040]    While circular flow path  16  is shown as positioned in a vertical plane, in another embodiment the circular flow path  16  could be in a horizontal plane (see  FIG. 12 ) or in a plane with an inclination between horizontal and vertical. 
         [0041]    In certain embodiments, as further illustrated in  FIG. 2 , a phase splitter  50  is in fluid communication with flow shaping line  17  to receive the liquid  18  flow therefrom. Phase splitter  50  may be in direct fluid communication with flow shaping line  17  or may be in communication with a flow line  43  disposed between the phase splitter  50  and flow shaping line  17 . In this regard, a flow line  43  may be utilized to stratify multiple liquid components within liquid  18  by stabilizing the fluid flow. For example, flow line  43  may be horizontally disposed so that liquids  18   a  with a first density, such as oil, separate from liquids  18   b  with a second density, such as water, by virtue of gravitational effects acting thereon. Alternatively, additional loops in flow shaping line  17  may be utilized to stratify the liquid components  18   a ,  18   b.    
         [0042]    Phase splitter  50  includes a housing having a liquid inlet  52  for receipt of liquid  18 , as well as a first liquid outlet  54  and a second liquid outlet  56 . A weir plate, foil or similar separation mechanism  58  is disposed within phase splitter  50  to direct a portion of the liquid  18  into first outlet  54  and allow a portion of the liquid  18  to pass into second outlet  56 . For example, weir plate  58  may be disposed to direct a substantial portion of liquid component  18   b  into first outlet  54 , while allowing liquid component  18   a  to pass over weir plate  58  into second outlet  56 . In this way, separation apparatus  10  may be used not only to separate gas from liquid, but also to separate liquid from liquid in instances where gas and multiple liquids comprise flow stream  12 . 
         [0043]    In certain embodiments, separation mechanism  58  may be adjustable in order to adjust the position of separation mechanism  58 , and hence, the cut of liquid removed from liquid  18 . Non-limiting examples of an adjustable separation mechanism  58  include an adjustable valve, adjustable weir plate or adjustable foil. A sensor  60  may be disposed to work in conjunction with and control an adjustable separation mechanism  58  based on a measured property of liquid  18 , such a cut. Although sensor  60  may be located anywhere along main line  15  or flow shaping line  17  or line  43 , it has been found that sensor  60  is preferably separated a sufficient distance from separation mechanism  58  to permit the position of separation mechanism  58  to be adjusted once the property of flow  12  has been determined. Likewise, in certain embodiments, sensor  60  is disposed along flow shaping line  17  or line  43  at a point where substantial liquid stratification has taken place, thereby increasing the accuracy of sensor  60 . In certain embodiments, sensor  34  and sensor  60  may be a single sensor utilized for multiple functions, such as to identify the cut of gas, a first liquid and a second liquid in flow  12 . 
         [0044]    Turning to  FIG. 4 , other embodiments of the invention are illustrated. In certain embodiments, the curvilinear flow path  16  is substantially in the form of a plurality of loops L 1  . . . L i , each loop characterized by a diameter D 1  . . . D i  that together comprise flow shaping line  17 . The loops L are disposed along an axis  62 . In certain embodiments, the diameter D of the loops L may remain substantially constant along the length of axis  62 , while in other embodiments, the diameter of the loops may increase or decrease, either randomly or successively. In the illustrated embodiment, the diameter D of successive loops decrease along the length of the flow shaping line  17  from the first end  64  to the second end  66  of flow shaping line  17 . 
         [0045]    The plurality of loops L may be provided to develop the increased concentration of the gas  22  on the inner wall  24  of the flow shaping line  17 . Moreover, the plurality of loops L increases the residence time of the flow  12  or liquid  18  through flow shaping line  17 . It may be desirable, for example, to increase residence time of the flow  12  or liquid  18  through the system  10  in order to measure the flow or liquid with sensors, such as the sensors  34 ,  60  described above, and make adjustments to adjustable mechanisms  30   b ,  58  based on the measurements prior to the flow  12  or liquid  18  reaching the adjustable mechanism. For example, the phase splitter  50  may be adjusted to separate liquid  18  into multiple phases, or the foil  30   b  may be adjusted to separate gas  22  from flow  12 . 
         [0046]    In this same vein, it may be desirable to alter the rate of the flow  12  or liquid  18  through system  10 . This is achieved by increasing or decreasing the diameter D of the loops L to achieve a particular flow rate for a particular deployment of system  10 . In one embodiment, for example, the diameter D of the loops L is decreased, resulting in an increase in velocity of the flow  12  from first end  64  to second end  66  which thereby results in greater centrifugal force and increased concentration of the gas  22  on the inner wall  24  of the flow shaping line  17 . 
         [0047]    Sensors  34  and  60  may be disposed anywhere along the flow path of system  10  as desired. Likewise, outlet  28  along inner wall  24  may be positioned anywhere along flow shaping line  17 , the position being selected as desired based on the components of flow  12 . Thus, outlet  28  may be positioned in the first loop L1 or a subsequent loop L, as illustrated. Likewise, liquid inlet port  42  may be in fluid communication with flow shaping line  17  or line  43  at any point in order to reintroduce liquid  18 ′ from separator  38  back into the main liquid  18  stream. 
         [0048]      FIG. 4  also illustrates an optional phase splitter  50  utilized in conjunction with the flow shaping line  17  shown.  FIG. 4  also illustrates an optional heater  68  utilized in conjunction with flow shaping line  17 . Heater  68  is particularly useful when the flow  12  includes certain liquid components which are desirably removed as a gas utilizing system  10 . For example, certain liquid hydrocarbons, such as methane or gasses that might move from liquid to gas at different flash or boiling temperatures, may be present in a flow  12  recovered from a wellbore (see  FIG. 11 ). Rather than recover the hydrocarbons as liquids, it may be desirable to heat the flow  12  using heater  68  to a temperature where the hydrocarbons convert to gas  22 , after which the hydrocarbon gas  22  can be removed through outlet port  28  and separator  38 . 
         [0049]      FIG. 5  illustrates the system  10  shown in  FIG. 4 , but with all of the loop diameters D approximately the same dimension. In the embodiment of  FIG. 5 , residence time may be maintained while the adjustable mechanism  58  in phase splitter  50  is adjusted based on one of the sensors  34 ,  60 . 
         [0050]      FIG. 6   a  illustrates the multi-loop system  10  shown in  FIG. 4 , but with two sets of loops. In this case, a first flow shaping line  17   a  and a second flow shaping line  17   b  are illustrated. Flow shaping lines  17   a ,  17   b  each have multiple loops L, which loops L may have substantially the same diameter D or successively increasing or decreasing diameters D. The flow can be divided and processed in parallel so that portions of the flow stream are simultaneously processed as described above, after which, the liquid from each set of loops can be recombined and directed towards outlet  72 . Multiple sets of loops arranged in parallel are particularly useful in cases of large flow volume 
         [0051]    The system  10  of  FIG. 6   b  is the same as that of  FIG. 6   a , but the loops L have substantially the same diameter D. The system of  FIG. 6   b  may also be used in conjunction with a heater  68 , cut sensors and adjustable cut mechanism  30   b  as described herein. 
         [0052]    With reference to  FIG. 7 , system  10  includes two sets of loops arranged in series. In this case, a first flow shaping line  17   c  and a second flow shaping line  17   d  are illustrated. Flow shaping lines  17   c ,  17   d  each have multiple loops L, which loops L may have substantially the same diameter D or successively increasing or decreasing diameters D. In the illustrated embodiment, in each set of loops, the loops L have a gradually decreasing diameter along the curvilinear flow path  16 . A heater  68  may be disposed to convert part of the flow  12  to a gaseous phase. Outlet port  28  to line  33  leading to separator  38  is positioned along the flow shaping line  17   c  at a point where it is expected a substantial amount of phase separation to have occurred after passing through at least a portion of the curvilinear flow path  176 . A sensor  34  is positioned in order to measure a property of the flow  12 . Sensor  34  is spaced apart along flow shaping line  17   c  a sufficient distance to allow the flow  12  to have a residence time in the loops prior to reaching outlet port  28  positioned on inner wall  24 , thereby permitting an adjustable separation mechanism, such as  30   b  shown in  FIG. 2 , to be adjusted accordingly. First flow shaping line  17   c  is intended to remove a large portion of the gas  22  that comprises fluid flow  12 . Thereafter, the liquid  18  passes through line  43  and into the second flow shaping line  17   d  to remove remaining gas that may be within the flow exiting the first flow shaping line  17   c . Again, a sensor  34  may be utilized in conjunction with an adjustable separation mechanism adjacent outlet port  28  of second flow shaping line  17   d.    
         [0053]    In one configuration of the system  10  shown in  FIG. 7 , flow shaping lines  17   d  operates as describe in  FIG. 2 , passing a liquid comprised of substantially first and second liquid components  18   a ,  18   b  into phase splitter  50 . A sensor  60  may be disposed along flow shaping line  17   d  to control an adjustment mechanism  58  disposed within phase splitter  50 . 
         [0054]    Multiple sets of loops are particularly useful in cases of large flow volume. The flow can be divided and processed in parallel so that portions of the flow stream are simultaneously processed as described above, after which, the liquid from each set of loops can be recombined and directed towards outlet  72 . 
         [0055]    Turning to  FIG. 8 , another embodiment of a flow shaping line  17  is illustrated. In this embodiment, flow shaping line  17  is shown in cross section and includes a channel  74  formed along the inner wall  24  of at least a portion of the curvilinear flow path  16 . Channel  74  may be utilized in any configuration of a flow shaping line  17  having a curvilinear portion, including flow shaping line formed in both single loop and multiple loop arrangements. It has been found that such systems  10  having a channel  74  are particularly effective in multi-phase flow regimes with a high gas to liquid content. In other words, flow  12  is comprised primarily of gas  22 , with a relative low amount of liquid  18  suspended therein. As flow  12  follows the curvilinear shape of flow shaping line  17 , the liquid  18  will become trapped within channel  74  and can be drained off through an outlet port  28  disposed along channel  74 . Thereafter, the separated liquid may be introduced into a second curvilinear flow shaping line  17  without a channel xx to permit separation of gas from liquid as depicted and discussed in the foregoing embodiments and illustrations. 
         [0056]      FIG. 9  illustrates one embodiment of an adjustable separation mechanism  58  for use in phase splitter  50 . Adjustable separation mechanism  58  is a ball valve  76  having a ball  78  rotatably mounted in a ball seat  80  carried within a phase splitter housing  82 . Ball  78  includes a first passageway  84  having an inlet  86  and an outlet  88 , as well as a second passageway  90  having an inlet  92  and an outlet  94 . Passageways  84  and  90  are formed in ball  78  so that inlets  86 ,  92  are adjacent one another, while outlets  88 ,  94  are spaced apart from one another. In one embodiment, passageways  84 ,  90  converge at inlets  86 ,  92  so that a portion of ball  78  defining passageways  84 ,  90  forms an edge  96 . As previously described, phase splitter  50  includes a liquid inlet  52 , a first outlet  54  and a second outlet  56 . Ball valve  76  is disposed in seat  80  so that the inlets  86 ,  92  are adjacent fluid inlet  52 , first ball outlet  88  is in fluid communication with first outlet  54  and second ball outlet  94  is in fluid communication with outlet  56 . In a preferred embodiment, edge  96  is positioned adjacent inlet  52 . Rotation of ball  78  thereby adjusts the position of edge  96  in liquid stream  18  as liquid stream  18  flows across edge  96 . In this way, valve  76  can be adjusted to alter the cut from liquid steam  18  such that a portion of the liquid  18   a  flows through first passageway  84  and a portion of the liquid  18   b  flows through the second passageway  90 . Persons of ordinary skill in the art will understand that passageways  84 ,  90 , and their respective inlets  86 ,  92  may be sized so that valve  76  may also be adjusted to divert all of liquid  18  flowing though inlet  52  into either first or second passageway  84 ,  90 , as desired. 
         [0057]    With reference to  FIG. 10 , a variable position gas control valve  98  is placed on the gas outlet  39  side of the two-phase separation vessel  38 . The liquid outlet  41  is unregulated and allowed to drain. As gas is allowed to escape the level increases in the vessel and when gas is not allowed to escape the level decreases. The incoming flow  40  is controlled and maintained at a specific level in separator  38  in order to stabilize the pressure therein so that liquid full flow bypass can be maintained without peeks or fluctuations in flow rate. 
         [0058]    As described above, one application for the invention is to protect against “kicks,” such as in subsea applications, by circulating out hydrocarbon gas at the seabed floor before the gas is able to rise up to a drilling rig. Referring to  FIG. 11 , in an exemplary embodiment, illustrated is a conventional sub-sea blow out preventer  150  located on the seafloor  152 . A marine riser  154  extends from the blow out preventer  150  and within the riser is a drillpipe  156 . One embodiment of the separation apparatus  110  is positioned along drillpipe  156 , preferably adjacent the blow out preventer  150 . In normal drilling operations, drilling fluid  158  is pumped down the drillpipe  156  from the drilling rig  157  and returns to the drilling rig  157  via annulus  160  formed between the drillpipe  156  and the riser  154 . If a “kick” is detected, such as by cut or similar sensors described herein, inlet annulus valve  162  is activated, diverting returning drilling fluid  158  from annulus  160  into the flow shaping line  117 . Flow shaping line may have one or multiple sets of coils. In the case of a single set of coils, flow shaping line is preferably arranged so that successive loops L along the line  117  having a decreasing diameter. In the case of multiple sets of coils, the flow shaping lines  117  may be arranged in parallel. Natural gas entrained in drilling fluid  158  from the “kick” is then separated from the drilling fluid  158  by the separation apparatus  110  as described above. Specifically, gas will exit flow shaping line  117  into a separator  138 . The natural gas then exits the gas-liquid separator  138  at the gas exit  139  and may flow up riser  166  to the drilling rig where it may be safely handled, for example, sent to a flare boom of the drilling rig  157 , or compressed and re-distributed (also not shown). 
         [0059]    Following separation of natural gas from the recovered drilling fluid  158  by separation apparatus  110 , the drilling fluid  158  is re-introduced into the annulus  160  at an exit annulus valve  168 . In comparison with the usual procedure of handling a kick, the use of an embodiment of this invention allows for full flow or circulation of the drilling fluid without having to choke down the flow or operate the blow out preventer valves. 
         [0060]    In another embodiment, the inlet annulus valves  162  or exit annulus valves  168  can be eliminated, bypassed or operated so that the upward flowing drilling fluid  158  continually flows through the separation apparatus  110 . Compared to the usual procedure on a drilling rig when there is a kick of choking the flow of the drilling fluid and being able to only send a portion of the flow to the mud-gas separator located on the drilling rig, an embodiment of the present invention allows the full flow of the drilling fluid to be handled by the separation apparatus  110  and the separation safely takes place near the seafloor. 
         [0061]    In one embodiment, flow shaping line  117  may comprise multiple loops of decreasing diameter as described above and illustrated in  FIG. 11 . In other embodiments, flow shaping line  117  may comprise a single loop or multiple loops of substantially the same diameter, but utilized in conjunction with a heater  68  to convert certain hydrocarbons to gas and/or a sensor  34  utilized in conjunction with an adjustable cut mechanism  30   b  (see  FIG. 2 ), such as a foil, weir plate or valve. 
         [0062]    In another embodiment illustrated in  FIG. 11 , a separation apparatus  210  having a flow shaping line  211  is utilized in conjunction with drilling and a hydrocarbon recovery system near the ground or water surface  212 . A fluid flow (such as fluid flow  12  in  FIG. 2 ) from a wellbore  216  is directed into flow shaping line  211  positioned adjacent a drilling rig  157 . In normal drilling operations, drilling fluid  158  is pumped down a drillpipe  156  from the drilling rig  157  and returns to the drilling rig  157  via annulus  160  formed between the drillpipe  156  and a pipe  154 , such as a riser in the case of marine drilling operations or a well casing in the case of land drilling operations. The recovered drilling fluid  158  from annulus  160  is directed into the flow shaping line  211 . Preferably, drilling mud and cuttings are first removed from the flow  214  using various systems  215  known in the industry before introduction into flow shaping line  211 . Natural gas entrained in drilling fluid  158  is then separated from the drilling fluid  158  by the separation apparatus  210  as described above. Specifically, gas will exit flow shaping line  211  into a separator  238 . The natural gas  164  exits the gas-liquid separator  238  at the gas exit  239 . 
         [0063]    In one embodiment, flow shaping line  211  may comprise multiple loops of decreasing diameter as described above and illustrated in  FIG. 4 . In other embodiments, flow shaping line  211  may comprise a single loop or multiple loops of substantially the same diameter, but utilized in conjunction with a heater  68  to convert certain hydrocarbons to gas and/or a sensor  34  utilized in conjunction with an adjustable cut mechanism, such as a foil, weir plate or valve. Moreover, separation apparatus  210  may include a phase splitter  220  in fluid communication with line  211  and disposed to separate liquid components as described above. 
         [0064]    In another embodiment illustrated in  FIG. 12 , a multi-phase flow separation apparatus  310  can be utilized in bunkering operations to supply ships with fuel. Bunker fuel generally refers to any type of fuel oil used aboard ships. Bunker fuels are delivered to commercial ships via bunker barges, which often hold the bunker fuel in large tanks  312 . The practice of delivering bunker fuels is commonly referred to as “bunkering”, as such bunker barges can also be known as bunkering barges. The bunker fuel is typically pumped from the barge&#39;s tanks  312  to the tanks  314  on commercial ships. At times, bunker fuels may be transferred between bunker barges. In any event, the pumping of fuel in bunkering operations, especially as the vessels containing the fuel are emptied, larger amounts of air tend to be drawn in and pumped with the fuel, rendering pumping difficult and resulting in inaccurate measurements of fuel. Thus, in certain embodiments, a system  310  is disposed in line between a first fuel storage vessel  312  and the vessel to which the fuel is being pumped, namely a second fuel storage vessel  314 . While system  310  may be of many different configurations as described herein, in certain preferred embodiments, system  310  includes, as shown in  FIG. 12 , a curvilinear flow path  316  in a flow shaping line  317 . Flow shaping line  317  includes a plurality of successive loops L of substantially the same diameter, each loop L being substantially horizontally disposed, thereby forming a “stack” of loops L. It has been found that in the case of loops L disposed substantially in the horizontal, the diameters of the loops, i.e., the coil sizes, do not need to be successively descending from the first end  364  of flow shaping line  317  to the second end  366  as is desirable in vertical orientation of the loops. Thus, fuel is removed from the first vessel  312 , passed through system  310  and then directed to the second vessel  314 . The fuel entering the first end  364  of flow shaping line  317  may have a large proportion of air included with the liquid fuel. The liquid fuel exiting the second end  366  of flow shaping line  317  has been substantially scrubbed of the entrained air. 
         [0065]    Although illustrative embodiments of the invention have been shown and described, a wide range of modification, changes and substitution is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Technology Category: b