[go: up one dir, main page]

WO2017119863A1 - Température et débit de pompe électrique submersible - Google Patents

Température et débit de pompe électrique submersible Download PDF

Info

Publication number
WO2017119863A1
WO2017119863A1 PCT/US2016/012019 US2016012019W WO2017119863A1 WO 2017119863 A1 WO2017119863 A1 WO 2017119863A1 US 2016012019 W US2016012019 W US 2016012019W WO 2017119863 A1 WO2017119863 A1 WO 2017119863A1
Authority
WO
WIPO (PCT)
Prior art keywords
motor
voltage
current
estimate
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2016/012019
Other languages
English (en)
Inventor
Souvik DASGUPTA
Dudi Rendusara
Sakthivel Kandasamy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schlumberger Canada Ltd
Services Petroliers Schlumberger SA
Schlumberger Technology BV
Schlumberger Technology Corp
Original Assignee
Schlumberger Canada Ltd
Services Petroliers Schlumberger SA
Schlumberger Technology BV
Schlumberger Technology Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schlumberger Canada Ltd, Services Petroliers Schlumberger SA, Schlumberger Technology BV, Schlumberger Technology Corp filed Critical Schlumberger Canada Ltd
Priority to PCT/US2016/012019 priority Critical patent/WO2017119863A1/fr
Publication of WO2017119863A1 publication Critical patent/WO2017119863A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/08—Units comprising pumps and their driving means the pump being electrically driven for submerged use
    • F04D13/10—Units comprising pumps and their driving means the pump being electrically driven for submerged use adapted for use in mining bore holes
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
    • E21B43/121—Lifting well fluids
    • E21B43/128—Adaptation of pump systems with down-hole electric drives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0066—Control, e.g. regulation, of pumps, pumping installations or systems by changing the speed, e.g. of the driving engine
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0088—Testing machines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/30—Control parameters, e.g. input parameters
    • F05D2270/303—Temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/30—Control parameters, e.g. input parameters
    • F05D2270/335—Output power or torque

Definitions

  • An artificial lift electrical submersible pump (ESP) to increase pressure within a reservoir to thereby encourage oil to the surface.
  • ESP electrical submersible pump
  • An artificial lift system often includes an electric submersible pump (ESP) driven by an induction motor. The ESP and induction motor are placed downhole and the motor is driven by an electric current produced by surface power equipment.
  • Various performance parameters associated with a downhole induction motor and electric submersible pump are determined based on surface measurements of current and voltage.
  • a method is described by which rotor temperature and/or pump flow rate is estimated. If either of these estimated parameters are determined to be outside of a normal operating condition, a corrective action may be taken (e.g., turning of the pump).
  • the parameters may be determined by measuring the voltage and current of each phase of a multi-phase distribution system to the downhole motor and, based on the measured voltage and current, estimating the voltage at the motor terminals. Positive and negative voltage and current sequences are extracted based on the motor terminal voltage estimates and measured currents.
  • Temperate can then be estimated for example by computing an estimate of rotor resistance from the extracted positive sequence voltage and current and then computing an estimate of temperature based on the estimated rotor resistance.
  • Flow rate can be estimated by estimating the direct current (DC) torque of the positive and negative voltage and current sequences, subtracting out a viscosity drag force estimate to estimate the total DC torque, computing output power of the motor based on the estimated total DC torque, and using power and motor speed as inputs to a flow rate determination operation.
  • a non-transitory storage device may include software that, when executed by a processing system, may cause the processing system to estimate temperature and/or fluid flow rate of electric submersible pump.
  • a system also is disclosed for estimating temperature and/or flow rate.
  • FIG. 1 illustrates an electric submersible pump including an induction motor and an associated control and monitoring system deployed in a wellbore environment in accordance with various embodiments of the present disclosure
  • FIG. 2 shows an example of an induction motor including multiple radial bearings in accordance with various embodiments
  • FIG. 3 shows an example of a method for estimating temperature of a rotor of an induction motor used down-hole to drive a pump in accordance with various embodiments
  • FIG. 4 shows an example of an approximately equivalent circuit model of the motor described herein in accordance with various embodiments
  • Fig. 5 illustrates an example of the estimation of rotor resistance in accordance with various embodiments
  • FIG. 6 illustrates another example of the estimation of rotor resistance in accordance with various embodiments
  • Fig. 7 depicts multiple series-connected motors for which individual rotor temperatures can be estimated in accordance with various embodiments
  • Fig. 8 shows an example of a method for estimating temperature of individual rotors in a multi-rotor motor configuration in accordance with various embodiments
  • Fig. 9 shows an example of a method for estimating flow rate of a downhole pump in accordance with various embodiments
  • Fig. 10 shows a technique for computing total DC torque from torques computed from positive and negative sequences
  • Fig. 1 1 shows a system diagram of a motor monitor processing system in accordance with various embodiments.
  • references to "based on” should be interpreted as “based at least on.” For example, if the calculation of parameter X is "based on" value Y, then the calculation of X is based at least on the value of Y; the calculation of X may be based on other values as well.
  • Coupled or “couples” is intended to mean either an indirect or direct connection.
  • the connection between the components may be through a direct engagement of the two components, or through an indirect connection that is accomplished via other intermediate components, devices and/or connections. If the connection transfers electrical power or signals, the coupling may be through wires or other modes of transmission.
  • one or more components or aspects of a component may be not displayed or may not have reference numerals identifying the features or components that are identified elsewhere in order to improve clarity and conciseness of the figure.
  • Electric submersible pumps may be deployed for any of a variety of pumping purposes. For example, where a substance does not readily flow responsive to existing natural forces, an ESP may be implemented to artificially lift the substance.
  • Commercially available ESPs such as the REDA ESPs marketed by Schlumberger Limited, Houston, Tex. may find use in applications that require, for example, pump rates in excess of 4,000 barrels per day and lift of 12,000 feet or more.
  • An ESP may include a pump that is driven by an electric induction motor.
  • a symptom of a failure or a potential future failure of a pump or motor is the temperature of the motor's rotor becoming excessive (e.g., greater than a threshold acceptable limit).
  • Another symptom of a problem or potential problem is a change in flow rate of the fluid being lifted by the ESP such that the flow rate is outside an expected range of normal values.
  • the disclosed embodiments include a processing system provided at the surface that analyzes an electric signal of the induction motor and, from that signal, estimates rotor temperature and/or fluid flow rate.
  • the current and voltage at the surface to be provided to the downhole motor are measured.
  • the terminal voltage of the downhole motor is estimated based on the surface measurement of current and voltage.
  • the estimated motor terminal voltage and the current are further processed to extract positive sequence voltage and current and, from the positive sequence values, the rotor's resistance is estimated. Temperature then can be estimated based on the rotor's estimated resistance.
  • a series connected set of multiple motors is provided downhole and the temperature of each such motor's rotor(s) is estimated.
  • motor input torque is estimated based on extracted positive and negative sequences of current and voltage.
  • Motor speed also can be estimated and, with the estimated torque, used to compute motor power.
  • Flow rate can be estimated based on the estimates of motor power and speed.
  • Temperature and/or flow rate then can be compared to their normal operating ranges and corrective actions (e.g., turning off the motor and pump) can be taken upon detecting a deviation from the normal range.
  • Fig. 1 depicts one example of a completion 10 within a well bore 12.
  • the completion 10 incorporates an electric submersible pump (ESP) 24.
  • ESP electric submersible pump
  • the presently disclosed systems and methods are independent of the completion architecture used in the specific application outside of the use of an ESP. While the systems and methods disclosed herein may be focused on hydrocarbon wells, it is understood that these and other embodiments may be used for any type of liquid being pumped with an ESP.
  • Non-limiting examples include: hydrocarbons from an oil well, water from a water well, water from a geothermal well, water from a gas well, hydrocarbons from a sump, and so on.
  • an ESP 24 may be deployed in the completion 10 in order to improve production of hydrocarbons.
  • the ESP 24 includes a motor 26 and a pump 30.
  • the motor 26 may be housed within the same housing as the pump 30, or may be housed separately.
  • the motor 26 operates to drive the pump 30 in order to increase hydrocarbon production to the surface.
  • the ESP 24 further includes an intake pressure gauge 32 which measures the pressure upstream of the ESP 24.
  • the ESP 24 further includes a discharge pressure gauge 34 which measures the pressure downstream of the ESP 24.
  • the motor 26 of the ESP 24 receives electrical energization from a switch gear such as a variable speed drive (VSD) 90 typically located at the surface, outside of the well completion.
  • VSD variable speed drive
  • the VSD 90 controls the power to, and thus the speed of, the motor 26.
  • the VSD 90 may be driven by a three-phase power source and thus may be a multi-phase power drive.
  • the VSD 90 delivers energization to the ESP 24 through an electrical conduit 38.
  • a digital acquisition system 95 also is included that receives an electrical signal of the VSD 90 and digitizes the signal.
  • the signal may include measurements of voltage and current for each of multiple phases 92.
  • the digital acquisition system 95 may include one or more analog-to-digital converts (DACs) to convert analog VSD signals to digital form.
  • DACs analog-to-digital converts
  • the motor monitor processing system 100 thus receives the digitized surface current and voltage measurement and processes them to estimate the temperature of the motor's rotor as well as fluid flow rate as is explained in detail below.
  • An alert 101 may be generated by the motor monitor processing system 100 to announce the detection of a problem (e.g., temperature and/or flow rate being outside a corresponding nominal range).
  • the motor monitor processing system 100 alternatively or additionally may generate a feedback signal 103 to be provided to the VSD 90 to change the operation of the motor 26 (e.g., reduce the speed of the motor, turn the motor off, etc.).
  • the motor 26 may be implemented as an induction motor (and thus may also be referred to as induction motor 26).
  • Fig. 2 shows a schematic of one example of induction motor 26.
  • induction motor 26 includes four radial bearings 32, 34, 36, and 38 and three rotor segments 40, 42, and 44.
  • the rotor segments 40-44 are arranged sequentially along their longitudinal axes.
  • a radial bearing (34, 36) is provided between each pair of adjacent rotor segments, and a radial bearing (32, 38) is provided at each end of the longitudinally-arranged rotor segments 40-44.
  • Any number of rotor segments and radial bearings can be provided other than what is shown in the example of Fig. 2.
  • rotor segment 40 On opposing ends of each rotor segment are rotor end rings.
  • rotor segment 40 includes end rings 50 and 52.
  • Rotor segment 42 includes end rings 54 and 56.
  • Rotor segment 44 includes end rings 58 and 60.
  • a shaft 62 is provided through the center of the rotor segments 40-44. As the rotor segments are caused to turn, the shaft 62 also turns. The speed at which the shaft 62 turns is referred to as the rotor shaft speed, shaft speed, and/or motor speed. Shaft speed may be expressed in units of revolutions per unit of time (e.g., revolutions per second).
  • the rotor segments 40-44 and radial bearings 32-38 are contained within a generally cylindrical stator 30. Alternating magnetic fields in the stator 30, caused by current from the VSD 90, cause the rotor segments 40-44 to turn.
  • Fig. 3 shows an example of a method for estimating temperature of a downhole induction motor's rotor.
  • the operations can be performed in the order shown, or in a different order. Further, two more of the operations may be performed concurrently rather than sequentially.
  • the method includes measuring the voltage and current at the surface.
  • the electrical power to operate the downhole motor and pump is a 3 -phase supply and thus, at 102, the voltage and current of each of the three phases is measured.
  • the output voltage and current of the VSD 90 is measured and digitized by the digital acquisition system 95.
  • a low resistance resistor may be provided on each of the three phase conductors and the voltage across the resistor is monitored and used as a proxy for the current of that phase.
  • the digitized measurements of current and voltage may be provided to the motor monitor processing system 100 which performs some or all of the rest of the operations of Fig. 3.
  • the method includes estimating the motor's terminal voltage, that is, the voltage at the input terminals of the motor itself, which may be connected through lengthy (dozens, hundreds or thousands of feet) cables to the VSD 90.
  • the estimate of motor terminal voltage may be based on the surface measured voltage as well as the surface measured current. As the motor may be located hundreds or thousands of feet downhole, due to the impedance of the electrical cables themselves that transfer power to the motor, the voltage at the motor will generally be less than the voltage at the surface.
  • m refers to the motor
  • x refers to the phase (e.g., phase a, phase b, phase c)
  • s refers to the surface (i.e., v S:X (t) is the voltage measured at the surface for each phase with respect to time)
  • Rcabie,x and L ca bie,x refer to the resistance and inductance of a cable of each phase from the surface to the motor
  • ⁇ - is the derivative of current of each phase with respect to time.
  • the estimated voltage at the motor's terminal as well as the currents may be unbalanced due to electrical asymmetry in the system such as cable asymmetry, motor lead extension (MLE) asymmetry, etc.
  • the illustrative embodiment of Fig. 3 for estimating rotor temperature may be performed by extracting the positive sequence voltage and positive sequence current (operation 106 in Fig. 3).
  • symmetrical components positive sequence, negative sequence, and zero sequence
  • permit analysis of power system operations during unbalanced conditions such as those caused by faults between phases and/or ground, open phases, unbalanced impedances, and so on.
  • the positive sequence set includes the balanced three-phase currents and line-to-neutral voltages provided by the VSD 90.
  • the positive sequence set is equal in magnitude and phase displaced by 120 degrees rotating at the system frequency with a phase sequence of normally a, b, c.
  • the negative sequence set is also balanced with three equal magnitude quantities at 120 degrees apart but with the phase rotation or sequence reversed, or a, c, b.
  • the members of the zero-sequence set of rotating phasors are equal in magnitude and are in phase.
  • the positive sequence component can be extracted as follows.
  • the estimated/calculated three phase motor terminal voltages and currents can be processed by a narrow bandpass filter to recover the content at the fundamental frequency.
  • the narrow bandpass filter may be tuned to the fundamental frequency detected in the estimated motor terminal voltage and current.
  • the narrow bandpass filter may be tuned to the fundamental frequency through a feedback signal generated by the combination of a zero crossing detector and adaptive tuner.
  • a phase-lock loop PLL may be used to provide an estimate of the fundamental frequency.
  • the motor monitor processing system 100 then extracts the positive sequence components from the filtered motor terminal voltages and currents.
  • the motor monitor processing system 100 also may extract the negative and/or zero sequence components. Any of a variety of techniques can be employed to extract the sequence components. For example, the sequence components of voltages and currents can be estimated using Fortescue's method. Per that method,
  • Xao (t) [Xa (t) + Xb (t) + Xc (t)] (5)
  • S is a phase shifter operator (e.g., S(120°)x(t) refers to shifting the phase of x(t) by 120 degrees in a positive direction and S(-120°)x(t) refers to shifting the phase of x(t) by 120 degrees in a negative direction).
  • the variable "x” in the above three equations refers to motor voltage or current.
  • xap(t) refers to the positive sequence component for current/voltage for phase a.
  • xaN(t) refers to the negative sequence component for current/voltage for phase a
  • xao(t) refers to the zero sequence component for current/voltage for phase a.
  • phase shifting operators can be implemented using the following equations:
  • the implementation can be performed using the following digital equations: Once the phase "a" positive sequence component for voltage and current is computed, the corresponding positive sequence voltages and currents can be calculated by shifting the phase "a" sequence components +/- 120°.
  • the method includes estimating the resistance of the rotor based on the extracted positive sequence voltage and current.
  • Various techniques can be employed by the motor monitor processing system 100 to estimate rotor resistance (designated as r r ). At least some of these techniques may be based on the approximate steady state equivalent circuit of the motor 26 as shown in the example of Fig. 4.
  • the resistance RM represents the coreloss resistance.
  • the resistance r s represents the stator resistance and is in series with the mutual inductance lh multiplied by a stator stray factor o s , as well as lh multiplied by a rotor stray factor Or and the rotor resistance r r divided by the rotor slip, S.
  • the mutual inductance is also provided as shown. These values can be computed through known techniques such as through use of an analytical, semi-empirical motor model, which uses as inputs motor winding code information, stator temperature information, and operating condition information (e.g., root mean square voltage and approximate horsepower.
  • the model outputs the various inductances, resistances, and factors.
  • Two other inductance values not shown in Fig. 4 are used below— stator inductance and rotor inductance.
  • the stator inductance l s and rotor inductance l r may be computed based on the mutual inductance and the stator and rotor stray factors o s and ⁇ ⁇ as:
  • Fig. 5 shows an example of a technique for estimating (108) rotor resistance based on extracted positive sequence voltage and current.
  • the blocks in Fig. 5 represent operations that may be performed by the motor monitor processing system 100.
  • the positive sequence motor voltages estimated for each phase a, b, and c i.e., v ma p, v m p, v mc p
  • an abc-to-alpha beta transformation operation 120 are provided as inputs to an abc-to-alpha beta transformation operation 120.
  • the positive sequence current values i a ip, IMP, icip
  • the result of the transformations 120 and 122 are a voltage space vector 3 ⁇ 4 5 and a current space vector if, respectively. These space vectors are computed with respect to the stator reference frame and both are provided as inputs to operation 124 at which the stator flux calculated.
  • stator resistance r s is estimated based on stator temperature, which may be obtained from a temperature sensor (e.g., a thermocouple) placed on the stator itself.
  • the stator temperature measurement may be transmitted to the motor monitor processing system 100 through known data transfer techniques.
  • the stator resistance may be computed from stator temperature through use, for example, of the equation (15) below:
  • T is the stator' s temperature
  • a is the thermal coefficient of resistance of the stator (a known value)
  • r s0 and T 0 is a predetermined stator resistance at a known temperature, respectively.
  • a resetting DC term also is provided as an input to operation 124 to subtract out any DC value present when computing the integral of Eq. (14).
  • the stator flux is then used to at 126 to calculate the rotor flux f with respect to the stator reference frame.
  • the rotor flux may be calculated with the following equation:
  • the rotor flux angle 6> r is extracted from rotor flux f .
  • the rotor flux angle is then provided to another transformation at 130.
  • This transformation may be an alpha beta-to-dq transformation which transforms the current space vector i s s to non-rotating current values i sq and i sd using the rotor flux angle 6 r .
  • These latter current values along with an estimate of the fundamental frequency ff un d (determined at 132 and discussed above) and an estimate of the rotor speed f r (determined at 134 using, for example, motor current signature analysis ("MCSA")) are provided as inputs to operation 136 at which the rotor resistance r r is computed.
  • the computation of rotor resistance may be computed as the slip frequency ⁇ 5 ⁇ (difference between fundamental frequency and rotor speed in units of radians per unit time) times the ratio of i sd to i sq . That is,
  • Fig. 6 illustrates another example of a technique for estimating rotor resistance
  • TV- Operations 120 and 122 are the same as described above to transform the voltage and currents to space vectors with respect to the stator reference plane.
  • the current space vector i s s is provided as input to operation 140 during which the magnitude l sd and angle 0 rl of that vector is computed.
  • Angle 0 rl is provided as an input to an alpha beta-to-dq transformation operation 142 along with the voltage space vector 3 ⁇ 4 5 .
  • the result of the transformation 142 are stationary voltages v sd and v sq which are inputs to operation 144 along with the fundamental frequency and rotor speed estimates.
  • Operation 144 calculates an estimate of rotor resistance and may be performed using the following equation:
  • the method includes estimating rotor temperature based on the estimated rotor resistance.
  • An example of an equation to estimate rotor temperature is:
  • T is the estimate of rotor temperature
  • a is the thermal coefficient of resistance of the rotor (a known value)
  • r r0 and T 0 is a predetermined rotor resistance at a known temperature
  • the motor monitor processing system 100 may compare the rotor temperature estimate T to a threshold value. If the rotor temperature is greater than the threshold (e.g., indicative of a problem), the motor monitor processing system 100 may take or at least initiate a corrective action at 114. Examples of corrective actions may include providing a feedback signal 103 to the VSD 90 to cause the VSD 90 to shut power off to motor 26 or reduce the voltage provided to the motor. Different or other corrective actions may be performed as well such as generating an alert 101 (e.g., text message, audible alarm, visual alarm, email, etc.).
  • an alert 101 e.g., text message, audible alarm, visual alarm, email, etc.
  • the downhole motor 26 includes multiple motors connected in series.
  • Fig. 7 shows an example of three sub-motors connected in series and comprising an upper tandem (UT) motor 152, a center tandem (CT) motor 154, and a lower tandem (LT) motor 156.
  • the above discussed technique for estimating rotor temperature can be extended to estimating the temperature of the rotors of the individual motors 152-156. Assuming that the motor has 'n' rotors, the voltage across each sub-motor is V lm p, V?mp, . . . , Vnmp, where 1 , 2, . . . , n identifies the sub-motor, "m” refers to the voltage estimated at the motor itself (as opposed to the surface measurement of voltage) and "P" refers to positive sequence voltages.
  • Fig. 8 shows an example of an embodiment of a method for estimating the temperature of individual rotors in a multi-rotor motor configuration.
  • the operations shown in Fig. 8 can be performed in the order shown or in a different order, and two or more of the operations may be performed concurrently.
  • the motor monitor processing system 100 may perform some or all of the operations shown.
  • the method includes measuring the surface voltages and currents of the various phases as explained above.
  • the method includes estimating the voltage and current at the downhole motor, again as explained above.
  • Operation 206 includes obtaining the temperatures of the individual stators across the various sub-motors.
  • a temperature sensor may be provided on or near each stator or for a corresponding rotor (i.e., each stator may be instrumented with a separate temperature sensor) and the stator temperature readings can be transmitted to the surface and received by the motor monitor processing system 100.
  • the motor monitor processing system 100 calculates the mean stator temperature (Tmean), for example, by dividing the sum of the individual stator temperatures by the number of stators.
  • Tmean mean stator temperature
  • the motor monitor processing system 100 extracts the positive sequence currents and voltages of the phases as explained above. These positive sequence currents and voltages are the voltages and currents of the collective series of connected sub-motors, not the voltages of the individual sub-motors.
  • the motor monitor processing system 100 calculates the mean positive sequence voltage of the sub-motors as the total positive sequence voltage for all sub-motors combined divided by the number of sub-motors. The resulting mean is designated as Vmean.
  • the method includes calculating the positive sequence voltage of each individual sub-motor (sub-motors 152, 154, and 156 in the example of Fig. 7).
  • the difference between the positive sequence voltage of a given sub-motor (V xm p) and the voltage mean for a given phase is given by:
  • V xmP — V mean (T sx — T mean ) X Ip (20) where the subscript x identifies the individual sub-motor, a is the thermal coefficient of resistance of the motor' s corresponding rotor, T sx is the temperature of the stator of that sub- motor, and Ip is the positive sequence current of the corresponding phase. Solving for the individual sub-motor voltage, V xm p, provides:
  • VxmP a (T sx — T mean ) X Ip + V mean (21)
  • Equation (21) thus is solved by the monitor processing system 100 to compute the positive sequence voltage for each rotor and for each phase.
  • the resistance of the rotor can be determined (216) in much the same way as described with respect to, for example, Figs. 5 and 6. Equation (19) then can be used to estimate the temperature of the corresponding rotor (218).
  • a thermal profile of the various rotors in the motor 26 can be determined.
  • a thermal event assessment can be determined for each individual rotor by comparing its temperature to a threshold as explained previously.
  • a corrective action can be initiated, for example, by the monitor processing system 100 if a given rotor temperature exceeds a threshold.
  • FIG. 9 shows an example of an embodiment of a method for estimating the flow rate of the downhole pump.
  • the operations shown in Fig. 9 can be performed in the order shown or in a different order, and two or more of the operations may be performed concurrently.
  • the motor monitor processing system 100 may perform some or all of the operations shown.
  • the method includes measuring the surface voltages and currents of the various phases as explained above.
  • the method includes estimating the voltage and current at the downhole motor for each phase, again as explained above.
  • Positive and negative voltage and current sequences are computed at 256.
  • the method includes computing (258) the electromagnetic DC torque for the positive voltage and current sequence and separately (260) for the negative voltage and current sequence.
  • Fig. 10 illustrates an example of this computation.
  • a motor stator induced electromotive force (emf) vector E sP is calculated at 280 based on the positive voltage and current sequence (at the fundamental frequency), as well as the motor per phase core-loss resistance (RM) and the motor per phase stator resistance (r s ).
  • the emf vector E sP may be computed as:
  • the interim current vector 11 may be computed as:
  • the dot vector operation is computed by multiplying corresponding elements of the E sP and the 11 vectors and summing the products together to generate an electromagnetic DC torque value for the positive sequence current and voltage. Similar calculations are performed for the negative current and voltage sequences at 290 and 292 to generate an electromagnetic DC torque value for the negative sequence current and voltage. The two electromagnetic DC torques (for the positive and negative voltage and current sequences) are then added together at 262 in Fig. 9 (as also illustrated at 295 in Fig. 10) to compute the total electromagnetic DC torque.
  • the method may comprise subtracting a viscosity drag force from the total electromagnetic DC torque to compute the DC torque generated by the motor.
  • a viscosity drag force Any of a variety of techniques can be employed to determine a viscosity drag force.
  • an oil drag force /viscosity model may be generated apriori for the particular motor being used, such as through empirical analysis. This model may also factor in a friction load value from the bearings. Inputs to such a model may include motor speed as determined by, for example, MCSA, oil temperature, and oil pressure.
  • the motor speed is estimated (and may have been estimated and used in operation 264 to compute a viscosity drag force) and used at 268 to compute the output power from the motor.
  • the motor's output power may be computed as the total electromagnetic DC torque computed at 264 multiplied by the motor speed.
  • the method includes determining the flow rate produced by the pump.
  • the motor's output power (which also represents the input power to the pump 30) and the motor speed (which also represents the pump's speed) are used, at least in part, to determine flow rate.
  • empirical studies can be performed on the pump (with a known number of pump stages) to measure flow rates for a known liquid (i.e., a liquid (e.g., water) with a known specific gravity), at a fixed reference speed, but at varying power levels for the pump. From such data, coefficients of a polynomial can be generated, and will be application specific based on the particular pump being tested.
  • the variable in the polynomial may itself be a function of pump input power, pump speed, and the specific gravity of whatever fluid is being pumped.
  • the variable (X) to be input into the polynomial can be calculated as:
  • the motor monitor processing system 100 determines whether the estimated flow rate is less than a particular threshold (which may be indicative of the lower range of a normal flow rate). If the flow rate is determined to be below the threshold, then a correct action may be initiated at 274 by the motor monitor processing system 100 as explained above. Otherwise, the process repeats.
  • a particular threshold which may be indicative of the lower range of a normal flow rate
  • Fig. 11 provides a system schematic of the motor monitor processing system 100 in accordance with an embodiment.
  • the system 100 includes a processing resource 302 coupled to a non-transitory storage device 304.
  • the processing resource 302 may be a single processor, a multicore processor, a single computer (desktop computer, notebook computer, tablet computer, etc.) multiple computing devices coupled together in a network, or any other type of computing device.
  • the non-transitory storage device 304 includes volatile storage such as random access memory (RAM), non-volatile storage such as a magnetic storage (e.g., hard disk drive), an optical storage device (e.g., compact disc), or solid state storage (e.g., flash storage).
  • the non- transitory storage device 304 may be a single device or collection of multiple devices, and be either stand-alone storage devices or storage devices contained within the processing resource 302.
  • the non-transitory storage device 304 contains motor assessment software 306 that, when executed by the processing resource 302, cause the processing resource to perform some or all of the functionality described herein.
  • the processing resource 302 can estimate, for example, rotor temperature and pump flow rate based on various inputs such as surface measured voltages and currents, stator temperatures, and other values as described herein. Alerts also can be generated or caused to be generated by the processing resource 302 as described above.
  • the techniques described herein permit the computation of the variables at each sampling instant without storing a long length value of current and voltage as well as statistical data. Use of statistical data is negligible. As such, the computation of temperature and flowrate can be computed quickly and efficiently.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Control Of Ac Motors In General (AREA)
  • Control Of Non-Positive-Displacement Pumps (AREA)

Abstract

L'invention concerne des procédés et systèmes pour estimer la température et/ou le débit de fluide d'une pompe électrique submersible (ESP). Des séquences de tension et courant positives et négatives sont générées sur la base des estimations de tension de borne du moteur et des courants de surface mesurés. La température peut alors être estimée, par exemple, en calculant une estimation de résistance de rotor à partir de la tension et du courant de la séquence positive extraite, puis en calculant une estimation de température sur la base de la résistance de rotor estimée. Le débit peut être estimé par estimation du couple à courant continu (CC) des séquences de tension et courant positives et négatives, soustraction d'une estimation de force de résistance de viscosité pour estimer le couple CC total, calcul de la puissance de sortie du moteur sur la base du couple CC total estimé, et utilisation de la puissance et de la vitesse du moteur en tant qu'entrées vers une opération de détermination de débit. Le fonctionnement de la pompe électrique submersible est réglable sur la base de la température et/ou du débit de fluide estimés.
PCT/US2016/012019 2016-01-04 2016-01-04 Température et débit de pompe électrique submersible Ceased WO2017119863A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2016/012019 WO2017119863A1 (fr) 2016-01-04 2016-01-04 Température et débit de pompe électrique submersible

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2016/012019 WO2017119863A1 (fr) 2016-01-04 2016-01-04 Température et débit de pompe électrique submersible

Publications (1)

Publication Number Publication Date
WO2017119863A1 true WO2017119863A1 (fr) 2017-07-13

Family

ID=59273795

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2016/012019 Ceased WO2017119863A1 (fr) 2016-01-04 2016-01-04 Température et débit de pompe électrique submersible

Country Status (1)

Country Link
WO (1) WO2017119863A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023056019A1 (fr) * 2021-10-01 2023-04-06 Schlumberger Technology Corporation Générateur d'esp

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070145835A1 (en) * 2005-12-28 2007-06-28 Jtekt Corporation Motor control apparatus and motor control method
US20090284204A1 (en) * 2008-05-16 2009-11-19 Square D Company Method and apparatus for estimating induction motor rotor temperature
US20110084638A1 (en) * 2009-10-12 2011-04-14 Gm Global Technology Operations, Inc. Methods, systems and apparatus for dynamically controlling an electric motor that drives an oil pump
US20120270325A1 (en) * 2011-04-19 2012-10-25 Ronald Kent Sperry System and method for evaluating the performance of a pump
US20150308244A1 (en) * 2012-11-26 2015-10-29 Moog Inc. Methods and system for controlling a linear motor for a deep well oil pump

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070145835A1 (en) * 2005-12-28 2007-06-28 Jtekt Corporation Motor control apparatus and motor control method
US20090284204A1 (en) * 2008-05-16 2009-11-19 Square D Company Method and apparatus for estimating induction motor rotor temperature
US20110084638A1 (en) * 2009-10-12 2011-04-14 Gm Global Technology Operations, Inc. Methods, systems and apparatus for dynamically controlling an electric motor that drives an oil pump
US20120270325A1 (en) * 2011-04-19 2012-10-25 Ronald Kent Sperry System and method for evaluating the performance of a pump
US20150308244A1 (en) * 2012-11-26 2015-10-29 Moog Inc. Methods and system for controlling a linear motor for a deep well oil pump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023056019A1 (fr) * 2021-10-01 2023-04-06 Schlumberger Technology Corporation Générateur d'esp
US20240380278A1 (en) * 2021-10-01 2024-11-14 Schlumberger Technology Corporation Esp generator
EP4409108A4 (fr) * 2021-10-01 2025-08-20 Services Petroliers Schlumberger Générateur d'esp

Similar Documents

Publication Publication Date Title
WO2016205100A1 (fr) Contrôle de pompe submersible électrique
US10753361B2 (en) ESP pump flow rate estimation and control
US8334666B2 (en) Device, computer program product and computer-implemented method for backspin detection in an electrical submersible pump assembly
WO2013055566A1 (fr) Procédé de vibration pour détecter un début de bouchon de gaz
CN103827683B (zh) 确定用于机电系统诊断的平稳信号的方法
CA2947986C (fr) Procedes et systemes de controle de dispositif de levage de fluide
US10113549B2 (en) Monitoring an electric submersible pump for failures
US20160084254A1 (en) Gas Lock Resolution During Operation Of An Electric Submersible Pump
WO2015073626A1 (fr) Test et surveillance de puits
US11959978B2 (en) Method of detecting a rotor bar fault and a method of estimating an additional operating expenditure due to one or more mechanical anomalies in an electrical machine
Liang Temperature estimation and vibration monitoring for induction motors and the potential application in electrical submersible motors
US12180825B2 (en) Advanced diagnostics and control system for artificial lift systems
WO2016115324A1 (fr) Systèmes et procédés pour le calcul de l'énergie électrique consommée par un moteur à induction
WO2017119863A1 (fr) Température et débit de pompe électrique submersible
EP3709500B1 (fr) Estimation de l'amplitude d'un composant périodique dans un signal mesuré par l'intermédiaire d'un modulateur delta-sigma
US10612363B2 (en) Electric submersible pump efficiency to estimate downhole parameters
WO2016204784A1 (fr) Surveillance d'un moteur de pompe submersible électrique à l'aide d'aimants
US20170051590A1 (en) Systems and Methods for Determining Forces on a Linear Permanent Magnet Motor Using Instantaneous Current Vectors
CA3188168A1 (fr) Systeme et methode pour le diagnostic d'evenements de pannes electriques dans les pompes submersibles electriques
Hussain et al. Position sensorless control of a permanent magnet linear motor connected through a long cable
Hussain Linear Permanent Magnet Machines for Oil Pumping Systems

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16884081

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16884081

Country of ref document: EP

Kind code of ref document: A1