WO2016049716A1

WO2016049716A1 - System for communication of data via an electrical network to a three-phase induction motor used in the artificial lifting method of submerged centrifugal pumping type

Info

Publication number: WO2016049716A1
Application number: PCT/BR2014/000360
Authority: WO
Inventors: Siqueira Karbage Elias; Pereira de Araújo Júnior Antônio; Ortiz Salazar Andres; Laurindo Maitelli André; de Assis de Oliveira Fontes Francisco; de Oliveira Quintaes Filipe
Original assignee: Petróleo Brasileiro S.A. - Petrobras; Universidade Federal Do Rio Grande Do Norte - Ufrn
Priority date: 2014-10-02
Filing date: 2014-10-02
Publication date: 2016-04-07

Abstract

The system of the present invention comprises two modules: the subsurface module - the signal transmitter - and the surface module - the signal acquisition module. The subsurface module is composed of a PLC transmitter circuit and an electrical coupling circuit. The purpose of this module is to obtain information from analogue sensors of the electric motor, carrying out analogue/digital conversion and transmitting the encoded data via the defined protocol. The surface module is composed of a PLC receiver circuit, an electrical coupling circuit and an electrical power supply source. The main purpose of this module is to decode the data present in the electrical network in the form of a pulse train. [002]. The system is responsible for the acquisition of the following data: pressure and temperature at the pump intake, internal motor temperature, discharge pressure, vibration signal and insulating oil contamination signal, with a view to preventing the burning-out of the three-phase induction motor used in the artificial lifting method of the submerged centrifugal pumping type.

Description

ELECTRICAL DATA COMMUNICATION SYSTEM FOR A THREE-PHASE INDUCTION MOTOR USED IN THE CENTRIFUGE PUMP ARTIFICIAL LIFTING METHOD

SUBMERGED

FIELD OF INVENTION

[001] The present patent for technological innovation refers to the development of a data communication system via the electric power of a three-phase induction motor, used in the BCS type artificial elevation method, consisting of two modules: the module subsurface - for signal transmission - and the surface module - for signal acquisition. The system will be responsible for the acquisition of pump pressure and inlet temperature, engine internal temperature, discharge pressure, vibration signal and insulating oil contamination signal data. The acquisition of this information has as its main objective to enable a broader and more reliable predictive analysis of the BCS suite for maintenance and operation decision making. This objective will be achieved by expanding data transmission capacity; increasing the frequency of data acquisition; increasing the reliability of real-time communication and data integration with the existing corporate well oversight system.

BACKGROUND OF THE INVENTION

[002] The BCS artificial lifting method is characterized by the use of a multistage centrifugal pump, driven by an electric motor, to lift fluids to the surface. In this method, electrical power is transmitted to the engine at the end of the production column via an electrical cable attached along the production column. This electrical energy is transformed into mechanical energy via a three-phase induction motor and transmitted to the pump. centrifuge, which by means of pressure differential will be responsible for raising the fluid to the surface.

[003] These motors are designed to operate submerged in production fluids under severe pressure and temperature conditions. They internally use an insulating mineral oil to maintain bearing lubrication, electrical insulation and engine cooling, as well as to prevent corrosion of components by contamination with the production fluid. The proper functioning, performance and integrity of BCS artificial lifting systems are conditioned to the effective monitoring of the variables provided by the proposed communication system.

[004] Power Line Communication (PLC) comprises a technology that uses the power grid as a physical means of data transmission. The principle of this technology was conceived in the 1930s, and applied in remote transmission to telegraph system. However, it has never been considered a reliable means of transmission due to its low speed, low functionality and high development cost. More recently, with the advancement of technology, there is a great growth in the use of PLC technologies for data transmission, due to the emergence of more effective techniques that ensure greater robustness and reliability to the transmission. PLC technology transforms an electrical distribution network into a communication network by superimposing a low power information signal on the high power alternating electrical signal.

[005] The technical aspects of PLC systems involve the coupling circuit, the transmission medium (the physical line itself), the modulation scheme to be used, the communication protocol and its corresponding implementation. PLC technology has a major advantage over other technologies for PLC transmission. data: the existence and use of basic infrastructure for communication.

[006] In some online electric motor monitoring applications, physical wiring is required between sensors installed at the motor end. However, additional cabling costs installed in an industrial environment are high. In addition, some applications do not allow additional cabling or wireless communication techniques, as they are located in harsh environments and with operating restrictions, for example, electric motors used for artificial lifting of oil by BCS.

[007] To date, there is no powerline data communication system for a three-phase induction motor used in the BCS artificial lift method capable of transmitting data collected from downhole contamination sensors. Contamination sensors are designed to detect and report the presence of electrolyte contaminants in the engine's insulating oil.

TECHNICAL STATE PROBLEMS

[008] In 2010, a magnetic insulating oil contamination sensor for the engines used in the BCS method was invented, with patent application no. PI 0903604-0 entitled: "Monitoring system for the detection of contamination of the insulating oil of the BCS electric motor ". However, this invention was limited to the exclusive development of the contamination sensor and transmitter modules.

[009] Modules currently available on the market do not have a contamination sensor installed on the subsurface. Thus, the problem with the prior art lies in the fact that there is no form of communication or alarm system electrolytic contamination condition of the insulating oil monitored through the patented contamination sensor.

[0010] With the advent of the present invention, it will be possible to perform predictive maintenance by analyzing the insulating oil contamination variable on motors used in wells equipped with the BCS type artificial lifting method. This will be of great importance to the oil industry as operating and maintenance costs tend to be significantly reduced by applying predictive rather than preventive or corrective maintenance.

SUMMARY OF THE INVENTION

[0011] In view of the problems presented, the present invention has been developed for the purpose of providing a powerline communication system, applied to oil insulated induction motors, for the purpose of transmitting the oil contamination signal to the surface, monitored by the contamination sensor. Therefore, this invention together with the patent application already required contamination will allow the prediction of the time before the engine contamination, allowing the programming of the well intervention probe.

[0012] Communication will be simplex (one way). The transmitter will be located at the base of the electric motor and will communicate over the mains with the receiver, which is also connected to the mains. The receiver, in turn, will be on the surface, accessible for viewing information from subsurface sensors. The communication protocol used injects low frequency current pulses (2 Hz) into the network.

[0013] The invented communication system has two modules: the subsurface module - signal transmitter - and the surface module - signal acquisition. [0014] The first module called the "subsurface module" is composed of an electrical coupling circuit and a PLC Transmitter circuit. This module aims to obtain information from analog sensors, performing analog-digital conversion and transmitting the coded bits through the protocol used. The Transmitter circuit is composed of a microcontroller capable of gathering sensor data, grouping it in protocol format and executing the bit-by-bit transmission process by injecting the pulse train into the power supply network. In this way, data from the sensors are transmitted to the surface.

[0015] The second module, called the "surface module", consists of: an electrical coupling circuit, an electrical power supply and a PLC receiver circuit. The main purpose of this module is to decode the bits present in the electrical grid as a low frequency signal.

[0016] The coupling circuit, common to both modules, aims to superimpose the data to the sine wave of the power grid. The coupling must allow the signal to be transmitted to the power grid and, at the same time, prevent the signal from the grid from entering the circuit, as this may affect the designed modules. Such a circuit also enables increased operational safety of the system.

[0017] The power supply, present in the surface module, is intended to supply electrical power to the subsurface module through the electrical network that feeds the motor.

[0018] The location of the modules is of fundamental importance to the present invention since no installation procedures of the BCS assembly will be changed in the field. The subsurface module will be mounted on the flanged connection of the motor base. The surface module will be installed in a panel on the surface allowing a supervision of the measured quantities.

BRIEF DESCRIPTION OF DRAWINGS

[0019] The features and advantages of the present invention may be better understood by the following detailed description based on the attached figures in which:

[0020] Figure 1 shows a schematic representation of the present invention.

[0021] Figure 2 shows a schematic view of the main components used in the BCS artificial lifting method, where the constituent elements of the present invention will be configured and installed, the original configuration being shown in figure 2 (left side) and the proposed configuration in figure 2 ( right side).

[0022] Figure 3 shows the scheme for understanding the operation of the PLC Transmitter circuit.

[0023] Figure 4 shows the scheme for understanding the PLC Receiver circuit.

DETAILED DESCRIPTION OF THE INVENTION

[0024] Figure 1 shows an electrical configuration characterizing the present invention. The signals from the sensors (1.1) are processed through a microcontroller present in the PLC Transmitter circuit (1.2). The microcontroller performs the analog-digital conversion of each measured variable and transmits the encoded bits through a pulse train, following the specifications of the protocol to be applied. The motor (1.3) installed in the well is fed through the power supply network (1.4). The subsurface module signal (1.8) is transferred via the same motor supply system (1.5). The couplings (1.6) are installed on the two modules, surface module (1.7) and subsurface module (1.8), interconnected through the power supply (1.4), which enables the transmitted signal to be passed to the motor supply system (1.5). This prevents the network signal from entering the PLC Receiver circuit (1.9). The data reception process consists of the signal passing through the electrical coupling circuit to demodulate the current pulses present in the network. After demodulation, sensor signals are provided via an operator interface (1.10), containing a surface mounted display or routed to a supervisory system (1.11).

[0025] Figure 2 presents some essential subsurface elements of the BCS artificial lifting method. The protective seal (2.1) represents the current and only means of protection against possible contamination of the motor insulating oil (2.2). The invented bottom sensor (2.3) is installed on the engine base flange, ie at the bottom of the shaft, when it is desired to measure or record pressure, temperature, vibration and contamination values. The invented background sensor (2.3) outputs signals to the surface using the same motor power cable. The subsurface module (1.8) is coupled to the motor base flange (2.2).

[0028] Figure 2 shows on the left side the original BCS assembly and on the right side the modification implemented on the BCS assembly by inserting the contamination sensor (2.4) between the protective seal (2.1) and the motor (2.2). The contamination sensor (2.4) will accompany the engine as an integral part of the engine and it is not necessary to change the installation and assembly procedures of the BCS assembly.

[0027] Figure 3 shows the scheme for understanding the PLC Transmitter circuit (1.2). This circuit is composed of a microcontroller capable of capturing the sensor data, grouping it in the defined protocol format and starting the bit-by-bit transmission process. [0028] The communication protocol used is programmed in the microcontroller firmware present in the transmitter and receiver, which checks for a transmission in progress. If not, it performs analog-digital conversion of the sensors and stores the data in its own memory. In the next send cycles, the microcontroller sends the bits referring to the protocol fields used and the data obtained in its memory.

[0029] Figure 4 shows the scheme for understanding the PLC Receiver circuit. Data reception consists of the signal passing through the electrical coupling circuit and its demodulation. At the end of the transmission, the microcontroller processes the data and sends the information to a display or supervisory system.

Claims

1. Powerline data communication system for a three-phase induction motor used in the artificial submerged centrifugal pump type lifting method, comprising:

- a subsurface module (1.8) coupled to the motor base flange (2.2), comprising: a PLC Transmitter circuit (1.2) and an electrical coupling circuit (1.6);

- a surface module (1.7) containing: a PLC receiver circuit (1.9) and an electrical coupling circuit (1.6);

where signals from sensors (1.1) are processed through a microcontroller present in the PLC Transmitter circuit (1.2) and the microcontroller performs analog-digital conversion of each measured variable and transmits the encoded bits through pulse train signals, following the specifications of a communication protocol which, after passing through the coupler circuit (1.8), couples the signals to the power supply network (1.4) resulting in pulse trains transferred through the same motor power system (1.5) as received coupling circuit (1.6) of the surface module by filtering the low frequency signals from the network and delivering the desired signals to the PLC Receiver circuit (1.9) by amplifying the signals in the amplification circuit (4.1) and demodulating the signals from the high frequency sensors by PLL filter (4.2) which are finally provided via an operator interface (1.10) containing a y surface mounted or routed to a supervisory system (1.11).

Data communication system according to claim 1, characterized in that the PLC Transmitter circuit (1.2) comprises a microcontroller, an analog digital converter and memory, and is responsible for the acquisition of sensor signals, analog / digital conversion and signal transmission through the power supply network.

Data communication system according to Claim 1, characterized in that the PLC Receiver circuit (1.9) comprises a microcontroller and a power supply and is responsible for decoding the bits present in the overlay signal of the mains, in the form of pulse train and electrically power the subsurface module (1.8).

Data communication system according to claim 1, characterized in that the electrical coupling circuit device (3.1) is responsible for providing the electrical network, for communicating data and increasing the operational safety of the PLC system.