Patent Description:
Ultrasonic flow meters transfer acoustic signals across fluids for flow measurements. Based on the acoustic signals, the ultrasonic flow meters determine average velocities of the fluids. An operator or other entity may calculate cross-sectional areas of the ultrasonic flow meters using known dimensions. Based on the average velocities and the cross-sectional areas, the ultrasonic flow meters determine volumes of the fluids flowing through the pipelines. An example of a prior art flow meter system is shown in <CIT>.

According to an embodiment, the flow meter system comprises a flow meter configured to enable a first flow of a first fluid through the flow meter, and transmitter electronics coupled to the flow meter and configured to calculate a first profile factor of the first fluid during the first flow, calculate a first meter factor corresponding to the first profile factor based on a single correlation between a plurality of profile factors and a plurality of meter factors for multiple fluids of different viscosities, and calculate a first volume of the first fluid using the first meter factor.

According to an embodiment, the method comprises enabling a first flow of a first fluid through a flow meter, calculating a first profile factor (PF) of the first fluid during the first flow, calculating a first meter factor (MF) corresponding to the first profile factor based on a single correlation between a plurality of profile factors and a plurality of meter factors for multiple fluids of different viscosities, and calculating a first volume of the first fluid using the first meter factor.

Any of the above embodiments may be combined with any of the other above embodiments to create a new embodiment.

The following abbreviations and initialisms apply:.

Disclosed herein are embodiments for multi-fluid measurement correction. The embodiments provide a correlation between PFs and MFs so that a flow meter system may calculate a different MF for each PF. By calculating and applying different MFs, the flow meter system makes more accurate measurements such as volume measurements within an error of about <NUM>% or less. In addition, the flow meter system makes measurements for multiple fluids. This is because fluids of different viscosities or Reynolds numbers may not have overlapping PF ranges. Thus, PF ranges of multiple fluids may be combined into a single correlation between PFs and MFs. Other approaches based on velocity or flow rate may not make measurements for multiple fluids using a single correction curve because different hydrocarbon fluids have different curves that cannot be combined.

<FIG> is a schematic diagram of a flow meter system <NUM>. The flow meter system <NUM> comprises pipes <NUM>, <NUM>, <NUM>; upstream flanges <NUM>, <NUM>, <NUM>; downstream flanges <NUM>, <NUM>, <NUM>; a flow conditioner <NUM>; transmitter electronics <NUM>; and a flow meter <NUM>. A similar system is described in <CIT> ("'<NUM> Patent"). A downstream direction is a direction from left to right in which fluids flow through the flow meter system <NUM>, and an upstream direction is a direction from right to left and opposite the downstream direction. The terms "downstream" and "upstream" are relative terms so that the downstream flange <NUM> is downstream from the upstream flange <NUM>, but upstream from the upstream flange <NUM>.

The pipes <NUM>, <NUM>, <NUM> comprise materials such as high-carbon steel or stainless steel and allow fluids to freely flow. The fluids may be hydrocarbon liquids such as crude oil or refined liquids. The pipe <NUM> may have a length of at least two times its diameter, the pipe <NUM> may have a length of eight times its diameter, and the pipe <NUM> may have a length at least five times its diameter. The upstream flanges <NUM>, <NUM>, <NUM> and the downstream flanges <NUM>, <NUM>, <NUM> comprise materials such as high-carbon steel or stainless steel. The upstream flange <NUM> and the downstream flange <NUM> facilitate coupling of the pipe <NUM> to the pipe <NUM>, the upstream flange <NUM> and the downstream flange <NUM> facilitate coupling of the pipe <NUM> to the flow meter <NUM>, and the upstream flange <NUM> and the downstream flange <NUM> facilitate coupling of the flow meter <NUM> to the pipe <NUM>.

The flow conditioner <NUM> conditions fluids flowing through it by eliminating swirls, reducing large-scale turbulence fluctuations, and improving mean velocity profiles of those fluids. The flow conditioner <NUM> does so in order to provide more accurate measurements at the flow meter <NUM>. The flow conditioner <NUM> may be a tube bundle that directs the fluids through a series of tubes or may be a perforated plate that directs the fluids through small apertures.

Compared to the ultrasonic flow metering system in the '<NUM> Patent, the flow meter system <NUM> does not comprise an expander, a reducer, or a pipe section connecting an expander or a reducer. Those components condition average velocity profiles of fluids and improve repeatability to enable measurements at Reynolds numbers below <NUM>,<NUM>. However, such flow velocity reduction may not be necessary in the flow meter system <NUM> because the flow meter system <NUM> is designed to perform measurements at Reynolds numbers between <NUM>,<NUM> and <NUM>,<NUM>.

<FIG> is a cross-sectional overhead view of the flow meter <NUM> in <FIG>. <FIG> shows that the flow meter <NUM> comprises a spool piece <NUM> and transducers <NUM>, <NUM>, <NUM>, <NUM>. The spool piece <NUM> defines a central bore <NUM> with a diameter D. The central bore <NUM> allows fluids to freely flow through it. The transducers <NUM>, <NUM>, <NUM>, <NUM> are acoustic transceivers that generate and transmit acoustic signals on one hand and receive acoustic signals on the other hand. The acoustic signals may be ultrasonic signals above about <NUM>.

For the transducers <NUM>, <NUM>, <NUM>, <NUM> to generate and transmit acoustic signals, the transmitter electronics <NUM> shown in <FIG> transmit analog electrical signals to the transducers <NUM>, <NUM>, <NUM>, <NUM>. Piezoelectric elements in the transducers <NUM>, <NUM>, <NUM>, <NUM> receive the analog electrical signals and vibrate in response, and the vibrations generate ultrasonic signals. The transducers <NUM>, <NUM> transmit the ultrasonic signals through fluids flowing through the central bore <NUM> and to opposing transducers <NUM>, <NUM>.

For the transducers <NUM>, <NUM>, <NUM>, <NUM> to receive acoustic signals, piezoelectric elements in the transducers <NUM>, <NUM>, <NUM>, <NUM> receive the acoustic signals and vibrate in response, and the vibrations generate analog electrical signals. The transducers <NUM>, <NUM>, <NUM>, <NUM> transmit the analog electrical signals to the transmitter electronics <NUM>. The transmitter electronics <NUM> detect the analog electrical signals, digitize the analog electrical signals to create digital electrical signals, and analyze the digital electrical signals.

A chord <NUM> exists between the transducer <NUM> and the transducer <NUM> at an angle θ with respect to a centerline <NUM> of the flow meter <NUM>. The chord <NUM> is a path for ultrasonic signals to travel from a point <NUM> in the transducer <NUM> to a point <NUM> in the transducer <NUM>, or for ultrasonic signals to travel from the point <NUM> in the transducer <NUM> to the point <NUM> in the transducer <NUM>. A chordal flow velocity υ of an acoustic signal traveling across the chord <NUM> is given by: <MAT> L is a length defining a linear distance of the chord <NUM> between the point <NUM> and the point <NUM>, X is a length defining an axial distance between the point <NUM> and the point <NUM>, Tup is a time it takes for an acoustic signal to travel from the point <NUM> to the point <NUM> or a time of flight in an upstream direction, and Tdown is a time it takes for an acoustic signal to travel from the point <NUM> to the point <NUM> or a time of flight in a downstream direction. υ is in units of m/s, L is in units of m, X is in units of m, Tup is in units of s, and Tdown is in units of s. Tdown is typically smaller than Tup because Tdown is the time of flight for ultrasonic signals traveling in approximately a same direction as fluid direction while Tup is the time of flight for ultrasonic signals traveling in approximately an opposite direction as the fluid direction. Though the chord <NUM> is described, another chord exists between the transducer <NUM> and the transducer <NUM> at the angle θ with respect to the centerline <NUM>. Similarly, a typical four-path ultrasonic flow meter has four chords.

<FIG> is a cross-sectional side elevation view of a portion <NUM> of the flow meter <NUM> in <FIG>. The portion <NUM> comprises the transmitter electronics <NUM> and the spool piece <NUM>. Like the cross-sectional overhead view in <FIG>, the cross-sectional side elevation view in <FIG> shows that the flow meter <NUM> comprises the transducers <NUM>, <NUM>, <NUM>, <NUM>. However, unlike the cross-sectional overhead view in <FIG>, the cross-sectional side elevation view in <FIG> also shows that the flow meter <NUM> comprises transducers <NUM>, <NUM>, <NUM>, <NUM> and thus four chords.

Chord A exists between the transducer <NUM> and the transducer <NUM>, chord B exists between the transducer <NUM> and the transducer <NUM>, chord C exists between the transducer <NUM> and the transducer <NUM>, and chord D exists between the transducer <NUM> and the transducer <NUM>. Chord C may be the same as the chord <NUM> in <FIG>. Using equation (<NUM>), the transmitter electronics <NUM> calculate υA for chord A, υB for chord B, υC for chord C, and υD for chord D. The transmitter electronics <NUM> also calculate PFs as follows: <MAT> PF is a dimensionless parameter. As can be seen, PF is a ratio of inner chordal flow velocities to outer chordal flow velocities, where chord B and chord C are inner chords and chord A and chord D are outer chords, and thus υB and υC are inner chordal flow velocities and υA and υD are outer chordal flow velocities.

<FIG> is a schematic diagram of a calibration system <NUM>. The calibration system <NUM> performs direct proving and may be referred to as a ball prover flow meter calibration system. The calibration system <NUM> comprises the flow meter system <NUM> in <FIG>, a connecting pipe <NUM>, and a ball prover <NUM>. The ball prover <NUM> is a piece of standard equipment that provides precision measurements when calibrated. The ball prover <NUM> is either straight or curved and comprises a ball <NUM>. The connecting pipe <NUM> connects the flow meter system <NUM> to the ball prover <NUM> so that the flow meter system <NUM> and the ball prover <NUM> are in series with each other. Thus, fluids enter the flow meter system <NUM> at point A, exit the flow meter system <NUM> at point B, move from point B to point C within the connecting pipe <NUM>, enter the ball prover <NUM> at point C, push the ball <NUM> from point C to point D within the ball prover <NUM>, and exit the ball prover <NUM> at point D. This system is called direct proving.

<FIG> is a schematic diagram of another calibration system <NUM>. The calibration system <NUM> is similar to the calibration system <NUM> in <FIG>. Specifically, the calibration system <NUM> comprises the flow meter system <NUM> in <FIG> and a ball prover <NUM>, and the ball prover <NUM> comprises a ball <NUM>. However, instead of the connecting pipe <NUM> like in the calibration system <NUM>, the calibration system <NUM> comprises a master meter <NUM>. An operator or other entity pre-calibrates the master meter <NUM> against the ball prover <NUM>.

<FIG> is a flowchart illustrating a method <NUM> of multi-fluid calibration according to an embodiment of the disclosure. At step <NUM>, MFs are calculated. An operator uses either the calibration system <NUM> or the calibration system <NUM> to calculate the MFs. Specifically, the operator calculates a volume Qref of the ball prover <NUM> or <NUM> as follows: <MAT> CSref is a known cross-sectional area of the ball prover <NUM> or <NUM>, and LC-D is a length of the ball prover <NUM> or <NUM> from point C to point D. Qref is in units of m<NUM>, CSref is in units of m<NUM>, and LC-D is in units of m. The operator obtains and determines a volume of a fluid. The operator causes the volume of the fluid to flow through the flow meter system <NUM> from point A to B. The flow meter system <NUM> calculates an average velocity of the fluid υavg given by: <MAT> υi is a chordal flow velocity for i = A-D, and wi is a chordal weighting factor for each chordal flow velocity υi. υavg is in units of m/s, υi is in units of m/s, and wi is a dimensionless parameter. The operator then causes the volume of the fluid to pass the ball <NUM> or <NUM> from point C to point D in the ball prover <NUM> or <NUM>, and the operator determines a time t it takes to do so. The operator calculates a volume QFMS of the flow meter system <NUM> as follows: <MAT> υavg is the average velocity of the fluid, CSFMS is a known cross-sectional area of the flow meter system <NUM>, and t is the time it takes the volume of the fluid to pass the ball <NUM> or <NUM> from point C to point D in the ball prover <NUM> or <NUM>. QFMS is in units of m<NUM>, CSFMS is in units of m<NUM>, and t is in units of s. The operator then calculates an MF of the flow meter system <NUM> as follows: <MAT> MF may be a constant around <NUM>, for instance <NUM>. As can be seen from equation (<NUM>), a ratio of a volume of the ball prover <NUM> or <NUM> to a volume of the flow meter system <NUM> yields MF.

At step <NUM>, PFs are calculated. Using equation (<NUM>), the transmitter electronics <NUM> calculate a PF while the fluid passes from point A to point B in the flow meter system <NUM>. PF in equation (<NUM>) may be a constant between about <NUM> and <NUM>. Steps <NUM> and <NUM> are repeated in order to obtain a plurality of MFs and plurality of corresponding PFs for the fluid. Steps <NUM> and <NUM> may be repeated to obtain a plurality of MFs and a plurality of corresponding PFs for additional fluids as well.

At step <NUM>, a correlation between the MFs and the PFs is established. For instance, the operator provides the MFs and the PFs to an algorithm. The operator may do so for multiple fluids. The algorithm generates an MF-PF curve based on the MFs and PFs. Such an algorithm is known in the art and may be a software program run on a separate computing device. The curve may be based on the following eighth-order polynomial equation:<MAT> The algorithm determines a<NUM>-a<NUM>. Alternatively, the operator provides the MFs and the PFs to the algorithm separately for each fluid, and the algorithm generates MF-PF curves for each fluid.

<FIG> is a graph <NUM> of MF-PF curves according to an embodiment of the disclosure. The x-axis represents a dimensionless PF, and the y-axis represents a dimensionless MF. A first curve <NUM>, which is represented by downward-facing triangles and which corresponds to a low-viscosity fluid at about <NUM> cSt, provides a first correlation between PFs and MFs. A second curve <NUM>, which is represented by diamonds and which corresponds to a high-viscosity fluid at about <NUM> cSt, provides a second correlation between PFs and MFs. The algorithm generates the first curve <NUM> and the second curve <NUM> using equation (<NUM>). The low-viscosity fluid has a PF range of about <NUM> to about <NUM>, the high-viscosity fluid has a PF range of about <NUM> to about <NUM>, and the low-viscosity fluid and the high-viscosity fluid overlap at a PF of about <NUM> in the graph <NUM>, so the correlation represents both low-viscosity fluids and high-viscosity fluids across a broad range of PFs from about <NUM> to about <NUM>. The algorithm may do so by separately generating the first curve <NUM> and the second curve <NUM>, or the algorithm may do so by generating a single curve that incorporates both the first curve <NUM> and the second curve <NUM>.

<FIG> is a graph <NUM> demonstrating a correlation between PF and Reynolds number. The x-axis represents a dimensionless Reynolds number, and the y-axis represents a dimensionless PF. A Reynolds number is a dimensionless parameter that describes whether a fluid is in laminar flow or turbulent flow. Typically, fluid flows with Reynolds numbers at or below <NUM>,<NUM> are laminar flows, fluid flows with Reynolds numbers between <NUM>,<NUM> and <NUM>,<NUM> are transitional fluid flows in which the state of the fluid flow may rapidly change between laminar flow and turbulent flow, and fluid flows with Reynolds numbers at or above <NUM>,<NUM> are typically turbulent flows. A first curve <NUM>, which is represented by downward-facing triangles and which corresponds to a low-viscosity fluid at about <NUM> cSt, provides a first correlation between Reynolds number and PF. A second curve <NUM>, which is represented by diamonds and which corresponds to a high-viscosity fluid at about <NUM> cSt, provides a second correlation between Reynolds number and PF. As shown, a single value for Reynolds number does not correlate to more than one value for PF. Thus, the correlation also represents both low-viscosity fluids and high-viscosity fluids across a broad range of Reynolds numbers. The graph <NUM> shows that the range of Reynolds number extends from about <NUM>,<NUM> to about <NUM>,<NUM>, but the correlation may represent fluids with a range of Reynolds number from about <NUM>,<NUM> to about <NUM>,<NUM> or any range therein.

Returning to <FIG>, at step <NUM>, the correlation is stored in the transmitter electronics <NUM>. For instance, the operator obtains the first curve <NUM> and the second curve <NUM> from the algorithm, combines the first curve <NUM> and the second curve <NUM> to form the correlation, and stores the correlation in the transmitter electronics <NUM>. The transmitter electronics <NUM> may store the correlation as user input values in firmware. The correlation provides a correction to measurements such as volume measurements that the transmitter electronics <NUM> make. By storing and applying the correlation in the transmitter electronics <NUM>, the flow meter system <NUM> may be referred to as a corrected or calibrated flow meter system or a MF-corrected or MF-calibrated flow meter system.

At step <NUM>, the flow meter system <NUM> is tested using the correlation. Step <NUM> may be referred to as verification. The operator uses the calibration system <NUM> to verify the flow meter system <NUM> in a manner similar to step <NUM>. Specifically, the operator causes a fluid to first pass through the flow meter system <NUM> and second pass through the ball prover <NUM>, and the operator calculates the MF of the flow meter system <NUM> according to equation (<NUM>). However, unlike at step <NUM>, the transmitter electronics <NUM> calculate a corrected volume QFMS' of the flow meter system <NUM> as follows: <MAT> As shown, the corrected volume QFMS' corrects the volume QFMS by multiplying the average velocity of the fluid υavg by MF. As mentioned above, υavg is an average velocity of the fluid, MF is an MF corresponding to a PF based on the correlation, CSFMS is the known cross-sectional area of the flow meter system <NUM>, and t is the time it takes for the volume of the fluid to pass the ball <NUM> from point C to point D in the ball prover <NUM>. QFMS' is in units of m<NUM>, υavg is in units of m/s, MF is dimensionless, CSFMS is in units of m<NUM>, and t is in units of s. The operator then calculates MF', a corrected MF of the flow meter system <NUM> as follows: <MAT> MF' should approach <NUM> because Qref and QFMS' should be about the same. Thus, if MF' is not <NUM> or within an error margin of <NUM>, then the operator repeats the method <NUM> until MF' is within the error margin. Once MF' is within the error margin, the method proceeds to step <NUM>. The error margin is <NUM>% or another error margin suitable for industry standards or other criteria.

Finally, at step <NUM>, measurements are performed using the correlation. For instance, the transmitter electronics <NUM> first calculate the PF according to equation (<NUM>), second calculate a corresponding MF according to the correlation, and third calculate a volume Q of fluid passing through the flow meter system <NUM> as follows: <MAT> As mentioned above, υavg is an average velocity of the fluid, MF is an MF corresponding to a PF based on the correlation, and CSFMS is the known cross-sectional area of the flow meter system <NUM>. However, in this case, t is the time it takes for the volume of the fluid to pass from point A to point B in the flow meter system <NUM>. Point A and point B can be as far away from each other as possible. Q is in units of m<NUM>, vavg is in units of m/s, MF is dimensionless, CSFMS is in units of m<NUM>, and t is in units of s. Though the PF, the corresponding MF, and the volume Q are described, other measurements such as individual chordal flow velocities, asymmetry in the velocity profile, and swirl angle may also be performed. By using MF in equation (<NUM>), the transmitter electronics <NUM> calibrate the flow meter system <NUM> by correcting a calculation or measurement of Q. The transmitter electronics <NUM> may do so for multiple fluids.

<FIG> is a flowchart illustrating a method <NUM> of fluid flow measurement according to an embodiment of the disclosure. The flow meter system <NUM> implements the method <NUM>. At step <NUM>, a first flow of a first fluid is enabled. For instance, the flow meter system <NUM> enables a first fluid to flow through the flow meter <NUM>. At step <NUM>, a first PF of the first fluid is calculated. For instance, the transmitter electronics <NUM> calculate the first PF using equation (<NUM>). At step <NUM>, a first MF corresponding to the first PF is calculated based on a correlation between PFs and MFs. For instance, the transmitter electronics <NUM> calculate the first MF based on the correlation described above with respect to step <NUM> in <FIG>. Finally, at step <NUM>, a first volume of the first fluid is calculated using the first MF. For instance, the transmitter electronics <NUM> calculate the first volume using MF as shown in equation (<NUM>).

<FIG> is a model <NUM> of multi-fluid calibration according to an embodiment of the disclosure. The transmitter electronics <NUM> implement the model <NUM>. Using υA-D as inputs, a PF and velocity computer <NUM> calculates PF using equation (<NUM>) and calculates υavg using equation (<NUM>). Using PF from the PF and velocity computer <NUM>, an MF-PF correlator <NUM> provides MF using the correlation described in step <NUM> in <FIG> above. In addition, using υavg from the PF and velocity computer <NUM>, a volume/flow rate calculator <NUM> calculates QFMS using equation (<NUM>). Finally, using MF from the MF-PF correlator <NUM> and using QFMS from the volume/flow rate calculator <NUM>, a corrector <NUM> calculates Q using equation (<NUM>).

<FIG> is a schematic diagram of an apparatus <NUM> according to an embodiment of the disclosure. The apparatus <NUM> implements the disclosed embodiments. The apparatus <NUM> may represent the transmitter electronics <NUM>, implement a portion of the transmitter electronics <NUM>, or implement a separate apparatus. The apparatus <NUM> comprises ingress ports <NUM> and an RX <NUM> to receive data; a processor, logic unit, baseband unit, or CPU <NUM> to process the data; a TX <NUM> and egress ports <NUM> to transmit the data; and a memory <NUM> to store the data. The apparatus <NUM> may also comprise OE components, EO components, or RF components coupled to the ingress ports <NUM>, the RX <NUM>, the TX <NUM>, and the egress ports <NUM> for ingress or egress of electrical, optical, or RF signals.

The processor <NUM> is any suitable combination of hardware, middleware, firmware, or software. The processor <NUM> comprises any combination of one or more CPU chips, cores, FPGAs, ASICs, or DSPs. The processor <NUM> communicates with the ingress ports <NUM>, RX <NUM>, TX <NUM>, egress ports <NUM>, and memory <NUM>. The processor <NUM> comprises a fluid measurer <NUM>, which implements the disclosed embodiments. The inclusion of the fluid measurer <NUM> therefore provides a substantial improvement to the functionality of the apparatus <NUM> and effects a transformation of the apparatus <NUM> to a different state. Alternatively, the memory <NUM> stores the fluid measurer <NUM> as instructions, and the processor <NUM> executes those instructions. Alternatively, any suitable combination of components implements the disclosed embodiments.

The memory <NUM> comprises one or more disks, tape drives, or solid-state drives. The apparatus <NUM> may use the memory <NUM> as an over-flow data storage device to store programs when the apparatus <NUM> selects those programs for execution and to store instructions and data that the apparatus <NUM> reads during execution of those programs. The memory <NUM> may be volatile or non-volatile and may be any combination of ROM, RAM, TCAM, or SRAM.

Claim 1:
A flow meter system (<NUM>) comprising:
a flow meter (<NUM>) configured to enable a first flow of a first fluid through the flow meter; and
transmitter electronics (<NUM>) coupled to the flow meter (<NUM>) and configured to:
calculate a first profile factor (PF) of the first fluid during the first flow,
calculate a first meter factor (MF) corresponding to the first profile factor (PF) based on a single correlation between a plurality of profile factors and a plurality of meter factors for multiple fluids of different viscosities, and
calculate a first volume of the first fluid using the first meter factor (MF).