WO2021054977A1

WO2021054977A1 - Acoustic production flow measurements

Info

Publication number: WO2021054977A1
Application number: PCT/US2019/052204
Authority: WO
Inventors: Freeman Lee HILL, III; Sushovon SINGHA ROY; Srinivasan Jagannathan
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2021-03-25

Abstract

A downhole flow measuring tool for determining a flow velocity within a wellbore is provided herein. The downhole flow measuring tool can include a body, at least one body support, and at least one pair of acoustic transducers mounted on the at least one body support, wherein the at least one pair of acoustic transducers communicate acoustic signals to determine a flow velocity corresponding to a volumetric flow rate within the wellbore. A first of the pair of acoustic transducers is configured to transmit an acoustic signal in a flow direction to a second of the pair of acoustic transducers, and the second of the pair of acoustic transducers is configured to transmit the acoustic signal against the flow direction to the first of the pair of acoustic transducers. A method of determining a volumetric flow rate within a wellbore and a downhole flow measuring system are also included.

Description

ACOUSTIC PRODUCTION FUOW MEASUREMENTS

TECHNICAL FIELD

[0001] This application is directed, in general, to monitoring of hydrocarbon wellbores and, more specifically, to an improved system and method for collecting production flow velocities and production volumetric flow rates.

BACKGROUND

[0002] In a highly deviated or horizontal well, fluid velocity cannot be adequately measured using a center sample tool, such as a full-bore flow meter, since the flow regime changes across the radius of the wellbore. There are different tools available in the market, which measure the fluid velocity along the radius of the borehole that conduct flow measurements using electro-mechanical spinners. These spinners often do not work properly, as they can become jammed with wellbore debris such as paraffin or ferrous material that is attracted by magnets used in such spinner. Also, these small spinners cannot measure very low flow rates or high flow rates since they have a high starting threshold and are disabled with high flow rates. Additionally, the arrangement used to measure the fluid velocity can substantially alter the flow velocity profile.

BRIEF DESCRIPTION

[ 0003 ] Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0004] FIG. 1 illustrates a downhole flow measuring system configured to perform subterranean production flow measurements; [0005] FIGs. 2A and 2B illustrate end view examples of flow measuring tool bodies positioned in a wellbore and constructed according to principles of the disclosure;

[0006] FIG. 3 illustrates a general example of an enhanced view of a flow measuring tool as positioned in a wellbore having production casing and constructed according to the principles of the disclosure;

[0007] FIG. 4 illustrates an example of a flow measuring tool as positioned in a production casing and constructed according to the principles of the disclosure;

[0008] FIG. 5 illustrates an example of sinusoidal pressure waveforms as may be associated with the flow measuring tool and casing structure of FIG. 2; and

[0009] FIG. 6 illustrates an example of a flow diagram of a method of determining a volumetric flow rate within a wellbore that is carried out according to the principles of the disclosure.

DETAILED DESCRIPTION

[0010] The disclosure addresses an alternative approach to measuring downhole fluid velocity without the use of mechanical spinners and with a deployment of sensors in a manner that does not appreciably affect the fluid velocity profile. In general, an acoustic waveform is stimulated into the wellbore fluids, where the amplitude is affected by the attenuation in the fluid, distance travelled and the flow velocity of a wellbore fluid. The velocity of an acoustic signal at which the signal travels through the borehole flow or production is affected by the material’s properties. The phase is also affected by the carrier fluid or material velocity. When a medium between the distances of two measure points is fixed (with a velocity of zero, or static), the amplitude of an acoustic signal traversing between the two points will show a decrease due to the fluid properties, and the phasing will be unaltered for the most part except in high attenuated mediums with predictable shifts.

[0011] However, as the medium starts to move ( i.e ., show velocity), both amplitude and phase will start to shift from the pre-observed static conditions. An acoustic wave traversing in the direction of flow will have a distinctive difference from one traversing in the alternate direction, against the direction of flow. These differences make a measureable, quantitative difference which has consistency and relationship to flow velocity. The same characteristics apply for acoustic pulses.

[0012] FIG. 1 illustrates a well system, generally designated downhole flow measuring system 100, including an operating environment wherein subterranean flow measurements are obtained. The subterranean flow measurements can be obtained in a wellbore that is fully cased, partially cased, or an open hole wellbore. In FIG. 1, the downhole flow measuring system 100 is illustrated in an environment with a wellbore 101 that extends from a surface 102 and is partially cased with casing 103. In the illustrated example, the flow measurements are obtained in an uncased section of the wellbore 101. The flow measurements can also be obtained within the casing 103, and in other operating environments, such as is a production environment where subterranean production flow measurements are obtained within production casing.

[0013] The downhole flow measuring system 100 includes a downhole flow measuring tool 110 that measures flow characteristics of fluids in the wellbore 101. The downhole flow measuring tool 110 has a depth correlation unit 120 that forms part of a logging operation that can be used for accurate depth control and locating the downhole flow measuring tool 110 within the wellbore 101. The downhole flow measuring tool 110 is attached to a conveyance 133 by an interface 115, which may be a connector, a wireline cable head, or other means of mechanically, electrically and/or optically coupling the downhole flow measuring tool 110 to the conveyance 133. The conveyance 133 may be a wireline, a slickline, tubing (including a coiled tubing), a downhole tractor, or another conveyance suitable for a logging operation. In one or more embodiments, the conveyance 133 may be a retrievable electrical logging cable that is capable of conveying or conducting electrical signals between the downhole flow measuring tool 110 and a logging unit 140. The conveyance 133 may include a wellbore communications link that sends control information downlink and receives downhole flow data and information uplink. In some examples, the conveyance may or may not conduct electricity and/or telemetry. Furthermore, a load sensor attached to the conveyance 133 between interface 115 and downhole flow measuring tool 110 may be present to further aid in determination of the depth profile along the conveyance 133.

[0014] The downhole flow measuring system 100 also includes a derrick 130 that supports a traveling block 131 and the downhole flow measuring tool 110 in the form of a sonde or probe that is lowered by the conveyance 133 into the wellbore 101. The downhole flow measuring tool 110 may be lowered to regions of interest in the wellbore 101, where formation fluids are flowing, such as from a subterranean formation 125. The downhole flow measuring tool 110 is configured to measure fluid properties of wellbore or formation fluids flowing in the wellbore 101. The downhole flow measuring tool 110 can then communicate the measurements via the conveyance 133 to the logging unit ( i.e ., a surface logging facility) 140 for storage, processing or analysis. The logging unit 140 is provided with electronic equipment 144, including data storage and a processor (or processors) 146, for various types of up-hole signal processing. The processor 146 may be employed for up-hole electronic or optical processing, provide downlink control of downhole tools, and augment data processing for a downhole tool. The depth correlation unit 120 in the downhole flow measuring tool 110 provides current depth data from the wellbore 101 through the conveyance 133 for recording of current depth data in the logging unit 140.

[0015] The downhole flow measuring tool 110 includes a plurality of acoustic transducers mounted on different body supports 134, 135 coupled to a body of the flow measuring tool 110 such that the plurality of acoustic transducers are functionally aligned to determine a flow velocity corresponding to a volumetric flow rate within the wellbore 101. Functionally aligned acoustic transducers are transducers that are communicatively connected to transmit and receive acoustic data therebetween. For example, first and second acoustic transducers are functionally aligned when a transmission from a first transducer provides a sufficient reception for a second transducer and a transmission from the second transducer provides a sufficient reception for the first transducer. A single one of the plurality of acoustic transducers is noted by element number 136 in FIG. 1, as an example. A first subset of the plurality of acoustic transducers transmits acoustic signals in a flow direction within the wellbore 101 to a second subset of the plurality of acoustic transducers and the second subset alternately transmits acoustic signals against the flow direction to the first subset to obtain measurements for determining the flow velocity. The body supports 134, 135, can have different configurations and shapes. For example, the body supports 134, 135, can be a single structure having a curved- shape or be in the shape of a triangle. The different body supports 134, 135 can be an angled support having a first portion and a second portion that extend from a body of the flow measuring tool 110. A group of the plurality of acoustic transducers can be mounted on the first portions and another group of the plurality of acoustic transducers can be mounted on the second portions. Each group can include two or more acoustic transducers. A more detailed example of a flow measuring tool having a body support and two groups of acoustic transducers mounted thereon is illustrated in FIG. 3. A downhole processor 112 is coupled to the downhole flow measuring tool 110 and can be configured to determine at least a portion of the flow velocity from the plurality of acoustic transducers measurements and the volumetric flow rate from the flow velocity. The downhole processor 112 may be, for example, a programmable logic device such as a programmable array logic (PAL), a generic array logic (GAL), a field programmable gate arrays (FPGA), or another type of computer processing device (CPD). The downhole processor 112 may provide local control of downhole tool functions and communicate with the up-hole processor of the electronic equipment 144 via the conveyance 133. In some examples, the downhole processor 112 and the processor 146 cooperate to determine the flow velocity and the volumetric flow rate.

[0016] FIGs. 2A and 2B illustrate two end view examples of flow measuring tool bodies positioned in a casing, generally designated 200, 250, and constructed according to principles of the disclosure. The downhole flow measuring tool body and wellbore example 200 includes a casing 205, a tool body 210, and first, second, and third body supports 215, 220, 225. The body supports 215, 220, 225, or at least some of the body supports 215, 220, 225, can be can angled body supports. Each body support can have two or more acoustic transducers mounted thereto. For example, as depicted in Fig. 2A, the first body support 215 includes 215A,B and 215C,D acoustic transducers, the second body support 220 includes 220A,B and 220C,D acoustic transducers, and the third body support 225 includes 225A,B and 225C,D acoustic transducers. The downhole flow measuring tool body and casing example 200 also includes three flow sectors 217, 222, 227 within the casing 205, as shown. [0017] Here, the first, second and third body supports 215, 220, 225 are located at the boundaries of the three flow sectors 217, 222, 227 shown. In this example, the two pairs of acoustic transducers mounted on each of the three body supports are employed to determine flow velocities proximate their body support. The arrangement of FIG. 2A accommodates averaging of determined flow velocities across each flow sector if the flow velocities vary from flow sector to flow sector. If each flow sector were to be redefined such that a corresponding body support was located in the middle of the flow sector instead of at the boundary, the two pairs of acoustic transducers mounted on the body support now centered in the flow sector would provide an average flow velocity for the flow sector.

[0018] In similar fashion, the tool body and casing example 250 of FIG. 2B includes a casing 255, a tool body 260, and six body supports 265, 270, 275, 280, 285, 290. The body supports 265, 270, 275, 280, 285, 290, or at least some thereof, can be angled body supports. As in example 200, each body support can have two or more acoustic transducers mounted thereto, e.g., each body support can have at least a pair of acoustic transducers mounted thereto. In some instances, each of the body supports 265, 270, 275, 280, 285, 290, has two pairs of acoustic transducers. For example, as depicted in Fig. 2B, the first body support 265 includes 265A,B and 265C,D acoustic transducers, the second body support 270 includes 270A,B and 270C,D acoustic transducers, the third body support 275 includes 275A,B and 275C,D acoustic transducers, the fourth body support 280 includes 280A,B and 280C,D acoustic transducers, the fifth body support 285 includes 285A,B and 285C,D acoustic transducers, and the sixth body support 290 includes 290A,B and 290C,D acoustic transducers. The flow measuring tool body and casing example 250 also includes six flow sectors 267, 272, 277, 282, 287, 292 within the casing 255. [0019] Here again, the six body supports 265, 270, 275, 280, 285, 290 are shown located between respective flow sectors and the two pairs of acoustic transducers mounted on each of the six body supports are employed to determine flow velocities proximate their angled body support. The flow sector resolution of FIG. 2B may be seen to be twice that of the flow sector resolution of FIG. 2A. The higher resolution of the tool body and casing example 250 may be advantageously employed when flow velocities are more varied across the flow area within a wellbore, such as within casing of a wellbore. Generally, by increasing the number of body supports with their pairs of acoustic transducers and averaging resulting flow velocities, a broader spectrum of flow regimes may be accurately accommodated. For example, four angled body supports with transducers may be employed in FIG. 2A, and eight body supports with transducers may be employed in FIG. 2B.

[0020] FIG. 3 illustrates an example of an enhanced view of a flow measuring tool as positioned in a casing of a wellbore, generally designated 300, constructed according to the principles of the disclosure. The wellbore 300 can be part of a production well wherein the casing is production casing. The positioned downhole flow measuring tool 310 includes an enhanced view of an angled body support 305 having a first portion 305A and a second portion 305B located between a downhole flow measuring tool body 310 and a wall of casing ( i.e casing wall) 315, as shown. The angled body support 305 includes four acoustic transducers 320A, 320B, 320C, 320D mounted to the angled body support 305, as shown. The four acoustic transducers 320A-320D may be employed to measure at least one fluid velocity between the flow measuring tool body 310 and the casing wall 315. Alternatively, the four acoustic transducers 320A-320D may be employed to measure a plurality of fluid velocities between the flow measuring tool body 310 and the casing wall 315. [0021] As indicated in FIG. 3, there are four pairings of the acoustic transducers that may be employed to determine flow velocities. The four pairings are represented by the dashed lines in FIG. 3 and indicate that the acoustic transducers are functionally aligned. These four pairings include transmissions between acoustic transducers 320A and 320B, transmissions between acoustic transducers 320A and 320D, transmissions between acoustic transducers 320B and 320C, and transmissions between acoustic transducers 320C and 320D. Here, transmissions between acoustic transducers 320A and 320B and acoustic transducers 320C and 320D are axially aligned in an alignment that is parallel with respect to the flow measuring tool body 310. Correspondingly, transmissions between acoustic transducers 320A and 320D, and transmissions between acoustic transducers 320B and 320C are axially aligned in an alignment that is inclined ( i.e non-parallel) with respect to the flow measuring tool body 310, such as non-parallel with respect to a centerline of the flow measuring tool body 310.

[0022] These transmissions are pairs of pressure transmissions that occur both with the direction of fluid flow and against the direction of fluid flow, as indicated. For example, a forward pressure signal P_AB is a pressure signal created between the acoustic transducers 320A and 320B in the flow direction, and a reverse pressure signal P_BA is a pressure signal created between the acoustic transducers 320B and 430A against the direction of fluid flow. The two pressure signals PAB, PISA- provide for determination of a flow velocity VAB between the acoustic transducers 320A and 320B. A similar determination and analysis may be employed for the three remaining acoustic transducer pairing to obtain flow velocities VAD, VCB, and VCD for the structure of FIG. 3. These flow velocities may be employed separately, averaged together or otherwise combined to describe a variety of flow patterns flowing through the casing structure of

FIG. 3. [0023] As noted above in the illustrated example, the acoustic pressure recorded by transducer B (320B) due to transmission by transducer A (320A) is denoted by P_AB· For a continuous pressure wave of frequency f, this can be denoted by Equation 1:

where /is frequency, DAB is the known distance between the transducers, vo is the fluid velocity ( i.e ., speed of flow of the fluid) and c is the fluid’s sound velocity ( ._<?., the speed of sound in the fluid). Similarly, the acoustic pressure recorded by transducer A (320A) due to transmission by transducer B (320B) may be denoted by Equation 2.

By extracting the phase of these two signals and finding the difference between them, the flow velocity between the two transducers A and B may be obtained. The flow velocities between the other transducer pairs indicated in FIG. 4 can be similarly determined.

[0024] FIG. 4 illustrates a diagram of an example of a portion of a production wellbore, generally designated 400, having a flow measuring tool 401 with a tool body 405 and a body support 415 positioned in a production casing 410. The positioned flow measuring tool may be employed for determining a flow velocity in a cased and producing hydrocarbon well wherein the flow velocity may be additionally employed in determining a volumetric flow rate for the producing well. As illustrated in FIG. 4, the body support 415 is an angled body support that has a first portion 416 and a second portion 417. In FIG. 4, the tool body 405 has an outer diameter of “a” and connections of the first portion 416 and the second portion 417 to the flow measuring tool 405 are separated by a distance “b”. Additionally, the body support 415 positions the tool body 405 a distance “c” from the inner diameter “d” of the casing 410. [0025] Each of the first and second portions 416, 417 can have two acoustic transducers mounted thereto (415 A, 415C mounted on the first portion 416 and 415B, 415D mounted on the second portion 417). Acoustic transducers 415A, 415C, can be considered a first group of acoustic transducers that transmit with the flow and acoustic transducers 415B, 415D, can be considered a second group of acoustic transducers that transmit against the flow. In this example, each group includes two acoustic transducers, wherein acoustic transducers from the first group are functionally aligned with acoustic transducers of the second group. In other examples, the first and second portions of an angled body support can have a group with more than two acoustic transducers mounted thereon.

[0026] As may be seen in FIG. 4, the tool body 405 can reduce the internal cross sectional area of the casing 410, thereby increasing the flow velocity due to the presence of the tool body 405 within the casing 410. The percentage of the flow velocity increase is a constant when the inner diameter of the casing 410 and dimensions of the tool body 405 are known, thereby providing a straight forward flow velocity correction. The percentage is a constant for a particular casing and tool body dimensions, thereby providing a straight forward flow velocity correction. This flow velocity correction approach may be applied to other tool body and casing configurations in addition to the configuration of FIG. 4. Additionally, FIG. 4 provides an example of acoustic sensor deployment along a single angled body support for a casing of a particular size. Similar ratios can be used for scaling the deployment of acoustic sensors along additional angled body supports and in casings of other sizes.

[0027] Using example values to demonstrate, the tool body 405 can have an outer diameter “a” of 1.69 inches, the connection points of the first portion 416 and the second portion 417 to the tool body 405 can separated by a distance “b” of 4.7 inches, the body support 415 can position the tool body 405 a distance “c” of 2.35 inches ( i.e “b” is two times “c”), and the casing 410 can be 7 inch casing having an inner diameter “d” of 6.4 inches. Using these values as an example, the tool body 405 can reduce the internal cross sectional area of the casing 410 by 6.97 percent thereby increasing the flow velocity by 7.5 percent due to presence of the tool body 405 within the casing 410.

[0028] FIG. 5 illustrates an example of sinusoidal pressure waveforms, generally designated 500, as may be associated with the flow measuring tools disclosed herein, such as within the wellbore casing structure of FIG. 3. Here, a first sinusoidal pressure waveform 505 is shown resulting from traversing in one direction from a first transducer to a second transducer, such as from transducer 320A to transducer 320B. Correspondingly, a second sinusoidal pressure wave 510 is shown resulting from traversing in an opposite direction from the second transducer to the first transducer, such as from transducer 320B to transducer 320A. Here, a resulting phase and amplitude shift may be employed to determine a fluid flow velocity. As noted before, equations 1 and 2 may be used to calculate fluid velocity (v₀) if the acoustic pressure PAB or P_BA is measured. In addition, the fluid’s sound velocity (c) for different fluids or mixture is a known parameter through other measurements and knowledge. Similarly, D is distance and/is frequency.

[0029] FIG. 6 illustrates an example of a flow diagram of a method of determining a volumetric flow rate within a wellbore, generally designated 600, carried out according to the principles of the disclosure. Acoustic transducers or groups of acoustic transducers as illustrated in FIGS. 1 to 4 can be used for the method 600. The method 600 starts in a step 605. Then, in a step 610, a first acoustic signal is transmitted in a flow direction within the wellbore from a first group of acoustic transducers to a second group of acoustic transducers. A second acoustic signal is transmitted against the flow direction within the wellbore from the second group of acoustic transistors to the first group of acoustic transducers, in a step 615. In a step 620, a flow velocity is determined corresponding to a volumetric flow rate within the wellbore using the first acoustic signal received by the second group of acoustic transducers and the second acoustic signal received by the first group of acoustic transducers. The first and second group of acoustic transducers are functionally aligned and can be mounted on at least one support extending from a body of a downhole flow measuring tool within the wellbore. The step 620 can be performed by a processor.

[0030] In one example, the processor determines the volumetric flow rate from the flow velocity. In another example, at least one of the first and second group of acoustic transducers is a piezoelectric transducer. In another example, the first and second group of acoustic transducers are mounted on a plurality of angled supports positioned at multiple locations around the circumference of the downhole flow measuring tool body within the casing. Correspondingly, the multiple locations around the circumference of the downhole flow measuring tool body include three or more locations. In yet another example, the first and the second acoustic signals can be continuous signals, including periodic signals such as a sinusoidal signal or a pulsed signal. The method 600 ends in a step 625.

[0031] While the method disclosed herein has been described and shown with reference to particular steps performed in a particular order, it will be understood that these steps may be combined, subdivided, or reordered to form an equivalent method without departing from the teachings of the disclosure. Accordingly, unless specifically indicated herein, the order or the grouping of the steps is not a limitation of the disclosure. [0032] The description and drawings included herein serve to illustrate the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the disclosure and concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles and aspects of the disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof. Additionally, the term, "or," as used herein, refers to a non-exclusive OR, unless otherwise indicated. Furthermore, directional terms, such as "above", "below", "upper", "lower", etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the different embodiments of the disclosure may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the disclosure.

[0033] A portion of the above-described apparatus, systems or methods may be embodied in or performed by various analog or digital data processors, wherein the processors are programmed or store executable programs of sequences of software instructions to perform one or more of the steps of the methods. The software instructions of such programs may represent algorithms and be encoded in machine-executable form on non-transitory digital data storage media, e.g., magnetic or optical disks, random-access memory (RAM), magnetic hard disks, flash memories, and/or read-only memory (ROM), to enable various types of digital data processors or computers to perform one, multiple or all of the steps of one or more of the above- described methods, or functions, systems or apparatuses described herein.

[0034] Portions of disclosed examples or embodiments may relate to computer storage products with a non-transitory computer-readable medium that have program code thereon for performing various computer-implemented operations that embody a part of an apparatus, device or carry out the steps of a method set forth herein. Non-transitory used herein refers to all computer-readable media except for transitory, propagating signals. Examples of non-transitory computer-readable media include, but are not limited to: magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM disks; magneto-optical media such as floppy disks; and hardware devices that are specially configured to store and execute program code, such as ROM and RAM devices. Examples of program code include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter.

[0035] Various aspects of the disclosure can be claimed including the apparatuses, systems and methods as disclosed herein include:

[0036] A. A downhole flow measuring tool for determining a flow velocity within a wellbore including (1) a body; (2) at least one body support coupled to the body, and (3) at least one pair of acoustic transducers mounted on the at least one body support, wherein the at least one pair of acoustic transducers communicate acoustic signals to determine the flow velocity corresponding to a volumetric flow rate within the wellbore, wherein a first transducer of the pair of acoustic transducers is configured to transmit an acoustic signal in a flow direction to a second transducer of the pair of acoustic transducers, and wherein the second transducer of the pair of acoustic transducers is configured to transmit the acoustic signal against the flow direction to the first transducer of the pair of acoustic transducers.

[0037] B. A method of determining a volumetric flow rate within a wellbore, including: (1) transmitting a first acoustic signal in a flow direction within the wellbore from a first transducer of a pair of acoustic transducers to a second transducer of the pair of acoustic transducers, (2) transmitting a second acoustic signal against the flow direction within the wellbore from the second transducer to the first transducer; and (3) determining a flow velocity, employing a processor, corresponding to the volumetric flow rate within the wellbore using the first acoustic signal received by the second transducer and the second acoustic signal received by the first transducer.

[0038] C. A downhole flow measuring system, including (1) a downhole flow measuring tool having a tool body with one or more body supports and having a plurality of acoustic transducers that are functionally aligned to provide flow velocity measurements corresponding to the volumetric flow rate within a wellbore, and (2) a processor coupled to the downhole flow measuring tool that determines a flow velocity within the wellbore from the flow velocity measurements and the volumetric flow rate from the flow velocity.

[0039] Each of aspects A, B and C can have one or more of the following additional elements in combination.

[0040] Element 1 further comprising a processor that determines the flow velocity and the volumetric flow rate from the flow velocity. Element 2 wherein one of the at least one pair of acoustic transducers is a piezoelectric transducer. Element 3 wherein the first transducer and the second transducer are axially aligned in parallel with respect to the body. Element 4 wherein the first transducer and the second transducer are axially aligned along an axis that is non- parallel with respect to the body. Element 5 wherein the at least one body support includes a first portion and a second portion that extends from the body. Element 6 wherein the first transducer is mounted on the first portion and the second transducer is mounted on the second portion of the at least one body support. Element 7 including multiple body supports that are each positioned at three or more locations around a circumference of the downhole flow measuring tool. Element 8 wherein the acoustic signal is a periodic signal that includes a sinusoidal signal or a pulse signal. Element 9 wherein the first and second transducers are mounted on at least one support extending from a body of a downhole flow measuring tool within the wellbore. Element 10 wherein at least one of the first and second transducers is a piezoelectric transducer. Element 11 wherein the processor determines the volumetric flow rate from the flow velocity. Element 12 further comprising transmitting acoustic signals between multiple pairs of acoustic transducers, wherein the multiple pairs of acoustic transducers are mounted on a plurality of angled supports positioned at multiple locations around a circumference of the downhole flow measuring tool body. Element 13 wherein the multiple locations around the circumference of the downhole flow measuring tool body include three or more locations. Element 14 wherein the first and the second acoustic signals are a continuous signal that includes a sinusoidal signal or a pulsed signal. Element 15 wherein the one or more body supports includes a first portion and a second portion that extends from the body. Element 16 including multiple body supports, wherein each of the body supports are positioned at two or more locations around a circumference of the downhole flow measuring tool. Element 17 wherein first and second acoustic transducers of the plurality of acoustic transducers are axially aligned in parallel with respect to a centerline of the tool body. Element 18 wherein the plurality of acoustic transducers include first and second acoustic transducers that are axially aligned along an axis that is non-parallel with respect to a centerline of the tool body. Element 19 wherein the processor is configured to control a downhole operation of the downhole flow measuring tool. Element 20 wherein the at least one of the plurality of acoustic transducers is a piezoelectric transducer. Element 21 wherein the plurality of acoustic transducers communicate acoustic transducer signals that are sinusoidal signals or pulse signals. Element 22 further comprising a wellbore communications link that sends control information downlink and receives downhole flow data and information uplink.

Claims

WHAT IS CLAIMED IS:

1. A downhole flow measuring tool for determining a flow velocity within a wellbore, comprising: a body; at least one body support coupled to the body; and at least one pair of acoustic transducers mounted on the at least one body support, wherein the at least one pair of acoustic transducers communicate acoustic signals to determine the flow velocity corresponding to a volumetric flow rate within the wellbore, wherein a first transducer of the pair of acoustic transducers is configured to transmit an acoustic signal in a flow direction to a second transducer of the pair of acoustic transducers, and wherein the second transducer of the pair of acoustic transducers is configured to transmit the acoustic signal against the flow direction to the first transducer of the pair of acoustic transducers.

2. The tool as recited in Claim 1, further comprising a processor that determines the flow velocity and the volumetric flow rate from the flow velocity.

3. The tool as recited in Claim 2, wherein one of the at least one pair of acoustic transducers is a piezoelectric transducer.

4. The tool as recited in any one of Claims 1 to 3, wherein the first transducer and the second transducer are axially aligned in parallel with respect to the body.

5. The tool as recited in any one of Claims 1 to 3, wherein the first transducer and the second transducer are axially aligned along an axis that is non-parallel with respect to the body.

6. The tool as recited in any one of Claims 1 to 3, wherein the at least one body support includes a first portion and a second portion that extends from the body.

7. The tool as recited in Claim 6, wherein the first transducer is mounted on the first portion and the second transducer is mounted on the second portion of the at least one body support.

8. The tool as recited in any one of Claims 1 to 3, including multiple body supports that are each positioned at three or more locations around a circumference of the downhole flow measuring tool.

9. The tool as recited in any one of Claims 1 to 3, wherein the acoustic signal is a periodic signal that includes a sinusoidal signal or a pulse signal.

10. A method of determining a volumetric flow rate within a wellbore, comprising: transmitting a first acoustic signal in a flow direction within the wellbore from a first transducer of a pair of acoustic transducers to a second transducer of the pair of acoustic transducers; transmitting a second acoustic signal against the flow direction within the wellbore from the second transducer to the first transducer; and determining a flow velocity, employing a processor, corresponding to the volumetric flow rate within the wellbore using the first acoustic signal received by the second transducer and the second acoustic signal received by the first transducer.

11. The method as recited in Claim 10, wherein the first and second transducers are mounted on at least one support extending from a body of a downhole flow measuring tool within the wellbore.

12. The method as recited in Claim 10 or 11, wherein at least one of the first and second transducers is a piezoelectric transducer.

13. The method as recited in any one of Claims 10 to 11, wherein the processor determines the volumetric flow rate from the flow velocity.

14. The method as recited in Claim 11, further comprising transmitting acoustic signals between multiple pairs of acoustic transducers, wherein the multiple pairs of acoustic transducers are mounted on a plurality of angled supports positioned at multiple locations around a circumference of the downhole flow measuring tool body.

15. The method as recited in Claim 14, wherein the multiple locations around the circumference of the downhole flow measuring tool body include three or more locations.

16. The method as recited in any one of Claims 10 to 11, wherein the first and the second acoustic signals are a continuous signal that includes a sinusoidal signal or a pulsed signal.

17. A downhole flow measuring system, comprising: a downhole flow measuring tool, including: a tool body with one or more body supports having a plurality of acoustic transducers that are functionally aligned to provide flow velocity measurements corresponding to a volumetric flow rate within a wellbore; and a processor coupled to the downhole flow measuring tool that determines a flow velocity within the wellbore from the flow velocity measurements and the volumetric flow rate from the flow velocity.

18. The system as recited in Claim 17, wherein the one or more body supports includes a first portion and a second portion that extends from the tool body.

19. The system as recited in Claim 17, including multiple body supports, wherein each of the body supports are positioned at two or more locations around a circumference of the downhole flow measuring tool.

20. The system as recited in any one of Claims 17 to 19, wherein first and second acoustic transducers of the plurality of acoustic transducers are axially aligned in parallel with respect to a centerline of the tool body.

21. The system as recited in any one of Claims 17 to 19, wherein the plurality of acoustic transducers include first and second acoustic transducers that are axially aligned along an axis that is non-parallel with respect to a centerline of the tool body.

22. The system as recited in any one of Claims 17 to 19, wherein the processor is configured to control a downhole operation of the downhole flow measuring tool.

23. The system as recited in any one of Claims 17 to 19, wherein the at least one of the plurality of acoustic transducers is a piezoelectric transducer.

24. The system as recited in any one of Claims 17 to 19, wherein the plurality of acoustic transducers communicate acoustic transducer signals that are sinusoidal signals or pulse signals.

25. The system as recited in any one of Claims 17 to 19, further comprising a wellbore communications link that sends control information downlink and receives downhole flow data and information uplink.