# US 10,480,308 B2 · Apparatus and method for monitoring fluid flow in a wellbore using acoustic signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,308 B2 - Document ID: US10480308B2 - Status: Granted - Kind: B2 - Application number: 14/434,732 - Filed: 2013-12-18 - Published: 2015-12-10 - Granted: 2019-11-19 - Earliest claimed: 2012-12-19 - Assignees: ExxonMobil Upstream Research Company - Applicants: Timothy I. Morrow; Stuart R. Keller; Max Deffenbaugh; Mark M. Disko; David A. Stiles - Inventors: Timothy I. Morrow; Stuart R. Keller; Max Deffenbaugh; Mark M. Disko; David A. Stiles; Scott W. Clawson; H. Alan Wolf; Katie M. Walker - Web page: https://patentgrep.com/patent/US10480308B2 ## CPC - E21B 47/16: through the drill string or casing {, e.g. by torsional acoustic waves} - E21B 47/10: Locating fluid leaks, intrusions or movements - E21B 47/14: using acoustic waves - E21B 49/00: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells - E21B 49/08: Obtaining fluid samples or testing fluids, in boreholes or wells - E21B 47/01: Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An electro-acoustic system for downhole telemetry employs a series of communications nodes spaced along a string of casing within a wellbore. The nodes allow wireless communication between transceivers residing within the nodes and a receiver at the surface. The transceivers provide node-to-node communication up a wellbore at high data transmission rates for data indicative of fluid flow within the wellbore. A method of monitoring the flow of fluid within a wellbore uses a plurality of data transmission nodes situated along the casing string sending signals to a receiver at the surface. The signals are then analyzed. ## Claims ### Claim 1 An electro-acoustic telemetry system for monitoring fluid flow in a wellbore, comprising: a tubular body disposed in a wellbore; a topside communications node placed proximate a surface of the wellbore; one or more sensors along the wellbore for at least one of sensing, monitoring, and measuring a parameter indicative of fluid flow within the wellbore and generating a sensor signal representative of fluid flow data; one or more sensor communications nodes associated with and in communication with at least one of the one or more sensors, each of the one or more sensor communications nodes configured to (i) receive a sensor signal from an associated sensor and (ii) transmit an acoustic signal indicative of the sensor signal to at least one of a plurality of subsurface communications nodes; the plurality of subsurface communications nodes spaced along the wellbore and attached to a wall of the tubular body, each of the plurality of subsurface communications nodes configured to receive and transmit acoustic communications signals indicative of the sensor signal from node-to-node up the wellbore within the tubular body and to the topside communications node; and a receiver at the surface configured to receive signals from the topside communications node; wherein each of the plurality of subsurface communications nodes comprises: an electro-acoustic transducer and associated transceiver in acoustic communication with the wall of the tubular body, with the transceiver being designed to relay the acoustic communications signals from node-to-node up the wellbore using the tubular body as an acoustic transmission medium, with each of the acoustic communications signals representing a packet of information that comprises an identifier for the sensor communications node that originally transmitted the signal, and the fluid flow data; and an independent power source providing electrical power to the transceiver; wherein adjacent nodes selected from the plurality of subsurface communications nodes represent pairs of nodes; wherein a receiving node in the pair of nodes is configured to detect amplitude and/or reverberation time for each tone received in a packet from a transmitting node in the pair of nodes, and then return the packet to the transmitting node; and wherein the transmitting node is configured to adjust its transmitting energy or its frequency band so that a weakest tone in the packet as returned by the receiving node will be received at a weakest signal amplitude for which communication remains robust, reduce a waiting time between tones to a smallest time required for the reverberation to substantially subside, and instruct the receiving node that it has made any changes in the transmitting energy, the waiting time, or the frequency band. ### Claim 2 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein the surface is an earth surface or a production platform offshore. ### Claim 3 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein the tubular body is one or more strings of casing, a string of production tubing, or a string of injection tubing. ### Claim 4 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein the subsurface communications nodes are spaced apart such that each joint of pipe supports at least one subsurface communications node. ### Claim 5 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein the subsurface communications nodes are spaced at about 10 to 100 foot (3.0 to 30.5 meter) intervals. ### Claim 6 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein each of the transceivers is designed to receive acoustic waves at a first frequency, and then transmit the acoustic waves at a second different frequency up the wellbore to a next subsurface communications node. ### Claim 7 (depends on 1) The electro-acoustic system of claim 1, further comprising: one or more sensors placed along the wellbore, the sensors being any of fluid flow measurement devices, temperature sensors, fluid identification sensors, pressure sensors, amp meters or volt meters that measure an electrical current that is passed along a body of the subsurface communications node, an electrical device that measures a capacitance of fluid, a microphone, a device for measuring fluid density, and a device for measuring rheology of fluid density in proximity to a corresponding subsurface communications node; and wherein the subsurface communications nodes are configured to receive and relay acoustic signals indicative of readings taken by the sensors up to the surface. ### Claim 8 (depends on 7) The electro-acoustic system of claim 7, wherein: the one or more sensors reside within housings of selected subsurface communications nodes; and the electro-acoustic transducers within the selected subsurface communications nodes convert signals from the sensors into acoustic signals for the associated transceivers. ### Claim 9 (depends on 7) The electro-acoustic system of claim 7, wherein: the one or more sensors reside adjacent to selected subsurface communications nodes; each of the one or more sensors is in electrical or optical communication with a corresponding selected subsurface communications node; and the electro-acoustic transducers within the selected subsurface communications nodes convert signals from the sensors into acoustic signals for the associated transceivers. ### Claim 10 (depends on 7) The electro-acoustic system of claim 7, wherein a frequency band for the acoustic wave transmission by the transceivers is about 25 KHz wide. ### Claim 11 (depends on 7) The electro-acoustic system of claim 7, wherein a frequency band for the acoustic wave transmission by the transceivers operates from about 100 kHz to 125 kHz. ### Claim 12 (depends on 7) The electro-acoustic telemetry system of claim 7, wherein the acoustic waves provide data that is modulated by (i) a multiple frequency shift keying method, (ii) a frequency shift keying method, (iii) a multi-frequency signaling method, (iv) a phase shift keying method, (v) a pulse position modulation method, or (vi) an on-off keying method. ### Claim 13 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: a well head is placed above the wellbore; and the topside communications node is placed (i) on an outer surface of the well head, or (ii) on the outer surface of an uppermost joint of the tubular body. ### Claim 14 (depends on 13) The electro-acoustic telemetry system of claim 13, wherein the signal from the topside communications node to the receiver is transmitted via a Class I, Division I conduit or a wireless transmission. ### Claim 15 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein the subsurface communications nodes are attached to the outer wall of the tubular body by (i) an adhesive material, (ii) welding, or (iii) one or more mechanical fasteners. ### Claim 16 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: each of the subsurface communications nodes is attached to the tubular body by one or more clamps; and each of the one or more clamps comprises: a first arcuate section; a second arcuate section; a hinge for pivotally connecting the first and second arcuate sections; and a fastening mechanism for securing the first and second arcuate sections around an outer surface of a pipe joint. ### Claim 17 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: the receiver comprises a processor; and the processor is programmed to identify amplitude values generated by each subsurface communications node and convert those into numerical values for graphing or for review. ### Claim 18 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: the one or more sensors are fluid flow measurement devices spaced along the wellbore proximate a subsurface formation, with each fluid flow measurement device being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to fluid flow measurement readings taken by the respective fluid flow measurement devices; and the fluid flow data in the acoustic waveforms comprises fluid flow measurement data. ### Claim 19 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: the one or more sensors are temperature sensors spaced along the wellbore proximate a subsurface formation, with each temperature sensor being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to temperature readings taken by the respective temperature sensors; and the fluid flow data in the acoustic waveforms comprises temperature data. ### Claim 20 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: the one or more sensors are pressure sensors spaced along the wellbore proximate a subsurface formation, with each pressure sensor being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to pressure readings taken by the respective pressure sensor; and the fluid flow data in the acoustic waveforms comprises pressure data. ### Claim 21 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein: the one or more sensors are fluid identification sensors spaced along the wellbore proximate a subsurface formation, with each fluid identification sensor being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to fluid identification readings taken by the respective fluid identification sensors; and the fluid flow data in the acoustic waveforms comprises fluid identification data. ### Claim 22 (depends on 1) The electro-acoustic telemetry system of claim 1, wherein each of the plurality of subsurface communications nodes receives and transmits acoustic communications signals indicative of the sensor signal from node-to-node up the wellbore within the tubular body and to the topside communications node at an acoustic transmission frequency within a range of from about 50 kHz to 500 kHz and acoustic data transmission rate of at least 50 bps. ### Claim 23 A method of monitoring fluid flow along a wellbore, comprising: running joints of a pipe into the wellbore, the joints being connected by threaded couplings to form a pipe string; placing a topside communications node along the wellbore; attaching a series of subsurface communications nodes to the joints of pipe according to a pre-designated spacing, wherein the subsurface communications nodes are configured to communicate by acoustic signals transmitted through the joints of pipe using an acoustic transducer in acoustic communication with at least one of the joints of pipe, and wherein each of the subsurface communications nodes comprises: an electro-acoustic transducer and associated transceiver configured to relay signals, with each signal representing a packet of information that comprises an identifier for the subsurface communications node originally transmitting the signal and fluid flow data; and an independent power source for providing power to the transceiver; sending signals from one or more sensors placed along the wellbore to selected sensor communications nodes, the signals being indicative of one or more fluid flow parameters; sending acoustic signals from the sensor communications nodes to a receiver at a surface via the series of subsurface communications nodes and the topside communications node, node-to-node; and analyzing the signals to evaluate fluid flow within the wellbore; wherein adjacent nodes of the series of subsurface communications nodes represent pairs of nodes; wherein a receiving node in the pair of nodes is configured to detect amplitude and/or reverberation time for each tone received in a packet from a transmitting node in the pair of nodes, and then return the packet to the transmitting node; and wherein the transmitting node is configured to adjust its transmitting energy or its frequency band so that a weakest tone in the packet as returned by the receiving node will be received at a weakest signal amplitude for which communication remains robust, reduce a waiting time between tones to a smallest time required for the reverberation to substantially subside, and instruct the receiving node that it has made any changes in the transmitting energy, the waiting time, or the frequency band. ### Claim 24 (depends on 23) The method of claim 23, wherein the surface is an earth surface or production platform offshore. ### Claim 25 (depends on 23) The method of claim 23, wherein the subsurface communications nodes are spaced apart such that each joint of pipe supports at least one subsurface communications node. ### Claim 26 (depends on 23) The method of claim 23, wherein the subsurface communications nodes are spaced at about 10 to 100 foot (3.0 to 30.5 meter) intervals. ### Claim 27 (depends on 23) The method of claim 23, wherein: the tubular body comprises one or more strings of casing, a string of production tubing, or a string of injection tubing; and each of the subsurface communications nodes includes a housing that is fabricated from a steel material, with the steel material of the housing having a resonance frequency within a width of the resonance frequency of the acoustic waves transmitted through the joints of pipe. ### Claim 28 (depends on 23) The method of claim 23, further comprising: placing the one or more sensors along the wellbore, the sensors the sensors being any of fluid flow measurement devices, temperature sensors, fluid identification sensors, and pressure sensors; and wherein the subsurface communications nodes are configured to receive and relay acoustic signals indicative of readings taken by the sensors up to the surface. ### Claim 29 (depends on 28) The method of claim 28, wherein: the one or more sensors reside within housings of sensor subsurface communications nodes; and the electro-acoustic transducers within the sensor communications nodes convert signals from the sensors into acoustic signals for the associated transceivers. ### Claim 30 (depends on 28) The method of claim 28, wherein: the one or more sensors reside adjacent to housings of sensor communications nodes; each of the one or more sensors is in electrical or optical communication with a corresponding sensor communications node; and the electro-acoustic transducers within the sensor communications nodes convert signals from the sensors into acoustic signals for the associated transceivers. ### Claim 31 (depends on 28) The method of claim 28, wherein a frequency band for the acoustic wave transmission by the transceivers is about 25 KHz wide. ### Claim 32 (depends on 28) The method of claim 28, wherein a frequency band for the acoustic wave transmission by the transceivers operates from about 100 kHz to 125 kHz. ### Claim 33 (depends on 28) The method of claim 28, wherein the acoustic waves provide data that is modulated by (i) a multiple frequency shift keying method, (ii) a frequency shift keying method, (iii) a multi-frequency signaling method, (iv) a phase shift keying method, (v) a pulse position modulation method, or (vi) an on-off keying method. ### Claim 34 (depends on 23) The method of claim 23, wherein: a well head is placed above the wellbore; and the topside communications node is placed (i) on an outer surface of the well head, or (ii) on the outer surface of an uppermost joint of the pipe string. ### Claim 35 (depends on 34) The method of claim 34, wherein the topside communications node is in electrical communication with the receiver by means of a Class I, Division I conduit or a wireless transmission. ### Claim 36 (depends on 23) The method of claim 23, wherein each of the subsurface communications nodes is attached to an outer wall of a joint of pipe by (i) an adhesive material, (ii) welding, or (iii) one or more mechanical fasteners. ### Claim 37 (depends on 23) The method of claim 23, wherein: each of the subsurface communications nodes is attached to a joint of pipe by one or more clamps; and the step of attaching the communications nodes to the joints of pipe comprises clamping the communications nodes to an outer surface of the joints of pipe. ### Claim 38 (depends on 37) The method of claim 37, wherein: each of the subsurface communications nodes includes a housing that comprises a first end and a second opposite end; and each of the one or more clamps comprises a first clamp secured at the first end of the housing, and a second clamp secured at the second end of the housing. ### Claim 39 (depends on 23) The method of claim 23, wherein: the one or more sensors are fluid flow measurement devices spaced along the wellbore proximate a subsurface formation, with each fluid flow measurement device being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to fluid flow measurement readings taken by the respective fluid flow measurement devices; and the fluid flow data in the acoustic waveforms comprises fluid flow measurement data. ### Claim 40 (depends on 23) The method of claim 23, wherein: the one or more sensors are temperature sensors spaced along the wellbore proximate a subsurface formation, with each temperature sensor being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to temperature readings taken by the respective temperature sensors; and the fluid flow data in the acoustic waveforms comprises temperature data. ### Claim 41 (depends on 23) The method of claim 23, wherein: the one or more sensors are pressure sensors spaced along the wellbore proximate a subsurface formation, with each pressure sensor being in electrical communication with a selected subsurface communications node; the selected subsurface communications node being designed to generate acoustic signals that correspond to pressure readings taken by the respective pressure sensor; and the fluid flow data in the acoustic waveforms comprises pressure data. ### Claim 42 (depends on 23) The method of claim 23, wherein: the one or more sensors are fluid identification sensors spaced along the wellbore proximate a subsurface formation, with each fluid identification sensor being in electrical communication with a sensor communications node; the sensor communications node being designed to generate acoustic signals that correspond to fluid identification readings taken by the respective fluid identification sensors; and the fluid flow data in the acoustic waveforms comprises fluid identification data. ### Claim 43 (depends on 23) The method of claim 23, further comprising: identifying a sensor communications node sending signals indicative of a need for remedial action; and actuating an inflow control device proximate the sensor communications node to adjust fluid flow into or out of the wellbore. ### Claim 44 (depends on 43) The method of claim 43, wherein the need for remedial action is prompted by water breakthrough, gas break through, or a loss of pressure. ### Claim 45 (depends on 43) The method of claim 43, wherein the step of actuating an inflow control device comprises sending an acoustic signal down the subsurface communications nodes and to the sensor communications nodes, where an electrical signal is then sent to the inflow control device. ### Claim 46 (depends on 23) The method of claim 23, wherein the subsurface communications nodes communicate by acoustic signals transmitted through the joints of pipe within a range of from about 50 kHz to 500 kHz and acoustic data transmission rate of at least 50 bps.