Application of the hottest SIMATIC control system

Application of SIMATIC control system in oil drilling equipment

Abstract: This paper summarizes the design method of system integration using Siemens SIMATIC 300 combined with specific examples of oil drilling equipment control system. The system uses step 7 software to program and debug, realizes the visualization of the scene through the protool software, realizes the data collection, historical archiving and report printing through the WinCC software, and realizes the redundant backup and remote maintenance functions

Keywords: data collection, historical archiving, redundant backup, remote monitoring

1 introduction

this project uses SIMATIC control system to be applied to zj30db and ZJ50DB variable frequency electric drilling rigs. Our company is a Sino foreign joint venture composed of four enterprises. Guided by science and technology, the company mainly produces oil drilling equipment and its supporting equipment, electrical control systems, engineering environmental protection projects, etc

Siemens SIMATIC 300 Series CPU is selected as the control core of variable frequency electric drilling rig, and the communication between PLC and frequency converter adopts PROFIBUS bus bus. Due to the high reliability and the complexity of maintenance caused by field operation, the system has redundant backup and remote monitoring functions

2 system introduction

the layout of the drilling equipment is divided into five areas: drill floor area, pump room area, power and electric transmission area, solid control area and oil tank area. The drill floor area is equipped with drawworks, rotary table, top drive, driller's room, driller's side room, etc. it is a dangerous operation area, and the electricity in the whole area is required to be explosion-proof. The pump room area is equipped with mud pump set, electric injection system and drilling fluid manifold; The power and electric drive area is equipped with diesel generator room, air source purification device room, auxiliary generator room and electric control room; The solid control area is equipped with mud circulating tank, mud purification equipment and packaged water tank; The oil tank farm includes oil tanks, pumps and pipelines. As the drill floor area is a dangerous explosion-proof area, the length of other areas from the wellbore shall be at least 50 meters according to relevant international and national standards. The whole set of PLC control system is arranged in the electric control room and the driller's room respectively to optimize the cost and performance. The electric control room includes two mutually redundant CPUs and a set of et200m, and the driller's room includes a set of et200m. The electric control room is equipped with PLC control cabinet, power generation cabinet, rectifier cabinet, VFD cabinet and MCC cabinet. The driller's room integrates the electromechanical, pneumatic and hydraulic control of the drilling rig. In addition to a set of et200m electric control cabinet, it also includes the main console and auxiliary console, with real-time display of drilling rig operation and drilling parameters, monitoring and display of electrical system operation, audible and visual alarm, fault indication, etc. The control system can complete the control and interlocking control of five motors above 600kW (including three mud pump motors, one winch machine and one rotary table motor); It also includes data acquisition, control, alarm and fault display of power generation cabinet, rectifier cabinet and drill floor sensor. During the drilling process, the reliability of the winch and rotary table is highly required. If the winch or rotary table fails and cannot be repaired in a short time, it may cause a major accident of shaft wall collapse. Therefore, the system has the function of redundant backup

3 composition of control system

the control station has redundant backup function and is composed of two SIMATIC CPU DP modules; Et200m is used to connect the field input and output points to the control station through PROFIBUS bus, and communicate with 5 ABB frequency converters through PROFIBUS; This is not only because the control must be based on the detected input information, the management room uses SIMATIC WinCC software to communicate with the control station through S7 protocol; Moreover, SIMATIC tc35t is externally connected to the control station through MPI port to realize remote maintenance

4 system functions

the drilling process overview of the whole rig is as follows:

winch device is mainly used for lifting and lowering derrick, substructure, hook and drill pipe; The rotary table device is used to make up and down the drill pipe and rotate the drill pipe to drive the drill bit to cut rock; The mud pump device injects high-pressure mud into the drill bit through the manifold, which not only lubricates and cools the drill bit, but also brings the mud mixed with rock debris back to the mud purification system for reuse

the functions of the whole drilling rig system mainly include:

(1) realize the communication between s CPU and ABB frequency converter through PROFIBUS bus to complete the control of corresponding motors. Determine the PPO type according to the number of transmission parameters, and write the corresponding communication program. Realize safety interlock for key drilling process. In case of failure, audible and visual alarm will be given on the panel of the operation console, and alarm or fault prompt will be given on the mp370 display panel

(2) mud pump control: the operator operates the panel of the driller's room and transmits the signal to the s CPU module of the control station through the Profibus DP of et200m to control the start, stop, speed setting and related interlock protection of the fans, spray pumps and main motors of the three mud pumps. Due to the large power of the motor, forced air cooling is required. After the mud pump fan is started, the main motor of the mud pump can be started only when the wind pressure switch is closed to establish the wind pressure

(3) winch control: use pulse encoder to calculate the hook height through fm350 module, and limit the highest and lowest positions to prevent "hitting up and hitting down"; It has "automatic control" function, which can determine whether it is in the automatic area (0 ~ 20%, 80 ~ 100% of the full stroke of the handle) according to the position of the speed given handle. In the automatic area, it can automatically control the running speed and stop position of the hook; Three speed selection ranges of high speed, low speed and ultra-low speed can be selected to adapt to different working conditions; When lifting and lowering the derrick and substructure, due to the large load weight, the "ultra-low speed" speed selection mode (0 ~ 60rpm) is used, and when lifting and lowering, the system has the function of energy consumption braking, making the operation stable and reliable

(4) turntable control: PROFIBUS DP protocol communication is used to control the speed setting value and torque limit value of the turntable frequency converter, and give the over-current and over-voltage alarm of the frequency converter

(5) software redundancy: in case of CPU failure caused by power supply unit, backplane bus, master station, hardware or software, redundant backup bus cable, redundant slave station interface with a large test force of 50kN or redundant slave station interface failure, a faulty master CPU can be taken over by the redundant CPU through SIMATIC software redundancy software - simple software mechanism, which has low requirements on the switching time of the master and standby system The redundant backup system or other special high reliability system is not absolutely necessary (considering the cost performance) system is more suitable. Using this software redundancy backup method can effectively improve the reliability of the system

(6) remote monitoring: remote monitoring can be achieved through GSM wireless communication network. Due to the particularity of the application site of oil drilling equipment (high reliability requirements, remote production site and poor environment), the on-site service cannot be fast and fast, and the maintenance cost is correspondingly large. Through SIMATIC teleservice software at the remote terminal, the cause of the fault can be analyzed in real time and the remote software upgrade can be realized. In this way, we can use resources more effectively, provide fast services, greatly reduce maintenance costs and maintenance time, and enhance the economy of the equipment

(7) human machine interface: two human machine interface display panels are set in the electric control room and the driller's room respectively. Through the configuration of the protool software, the operation status of the equipment and the operation logic status of each motor are displayed, and the operation of the field equipment is monitored. A fault page display is set to facilitate fault location and maintenance

(8) historical archiving and report printing: completed by the PC set in the manager's office. Prepared with SIMATIC WinCC software and using Microsoft's SQL server as a database management tool, Visual C realizes the query of historical archived data and the configuration of dynamic pictures, and can realize the functions of report, trend and alarm printing, so as to provide help for managers to analyze data

5 conclusion

the whole system realizes the distributed centralized control of drilling equipment. The s CPU set in the electric control room collects the equipment status and controls the operation of the field equipment through the field distributed i/o module. It has the functions of complex program control and conventional interlocking protection, and realizes the visualization of the operation status of the field equipment through two display panels. The system also has the functions of historical archiving and report printing, so that the whole system has strong technical advantages and competitiveness

since the plan is to use the PLC control system of Siemens for the first time, the communication of the whole system adopts the Profibus electrical network. The driller's room in the system is far from the electric control room (60m), and the initial communication rate of the system is 1.5mbps. However, during the field commissioning, it is found that the communication interruption often occurs in the distributed i/o slave station set in the driller's room, According to the design requirements, the relay at the bus terminal and the terminal resistance of the bus connector are all placed in the "on" position. This makes on-site debugging, fault finding and troubleshooting take a long time. However, according to the manual, the communication rate should reach 12mbps. The communication rate set in the system is 1.5mbps. The communication should be reliable, but reduce the baud rate to 500kbps. The system operates safely and reliably for a long time, and there is no communication failure. This means that six sets of fixtures of the equipment can stop seven different experiments in good condition, indicating that there are problems in the communication quality of the system. After analysis, the communication line from the electric control room to the driller's room is greatly disturbed by the power line

how to determine the communication rate of the reliable and safe operation of the system and how to optimize it according to the topology structure of the network and the hardware connection of the bus are facing us. At present, Siemens has launched special instruments for detecting the communication quality of PROFIBUS system, which can improve the extension structure and hardware wiring according to the monitoring results, so as to facilitate equipment installation, commissioning, fault location and maintenance; In addition, in terms of cost performance, optical fiber communication is also a feasible scheme. From the commissioning and operation of field equipment, the reliability and flexibility of SIMATIC PLC control system are obvious to all. We believe that we will have more equipment to use SIMATIC control system. (end)