Visualization and control of the oil metering system at Genaveh Oil Terminal in Iran

June 2, 2016 | Reliance SCADA

In 2015, Delta Gas Mobin Group implemented a system for the monitoring and control of the oil metering system at Genaveh Oil Terminal in Iran.

The metering system comprises ten meter runs with ultrasonic oil flow meters, including each meter run's inlet and outlet.

Meter run = a piece of pipe that is equipped with all necessary instruments
for custody transfer flow metering

Each meter run is equipped with the following elements:

Two motor-operated isolation valves
Ultrasonic oil flow meter
Absolute or gauge pressure transmitter
Temperature transmitter
Local indicators for temperatures and pressures
Prover motor-operated isolation valve
Flow control valve
Strainer

To verify the accuracy of flow measurement (automatically/manually), a bidirectional pipe prover is used.

Control system

The elements of each meter run are wired to the flow computing, monitoring, and supervisory cabinet (control cabinet), which is installed in the control room. Two server PCs and two printers are located in the operator's room. Each PC is equipped with Reliance's runtime software and is connected to the control cabinet through a redundant Ethernet link. The software has different access levels, which protect the system against unwanted access. Required field and calculated signals are transferred to the distributed control system. The system is equipped with one Siemens SIMATIC S7-400H PLC to control the operation of the motor-operated isolation valves. Flow calculations are done by using thirteen Flow-X flow computers. The Reliance SCADA system communicates with the PLC and the flow computers via a redundant Modbus Ethernet link. One of the advantages of Reliance in this project is that it has built-in drivers for both the PLC and the flow computers.

The Reliance SCADA system provides the following functionality:

Modification of operational parameters and settings, such as alarm and deviation limits, transmitter overrides
Graphical-oriented operator screens displaying important metering data–related information from the flow computers, flow meters, transmitters, and valves
Data transparency towards the operators
Operating feedback from the motor-operated isolation valves
Generating custody transfer reports and other reports
Archiving of reports, alarms/events, and trends
Secure environment by protecting the system from unauthorized access
Alarm management; alarms are derived from primary input signals as well as from calculated figures, they can be printed on the alarm printer, and are stored on the hard disk
Real-time and historical trending for all major signals in the system
Monitoring of all important signals with high and low limits; generating an alarm if any of the signals is out of the normal range
Human–machine interface with which the operator can monitor, for example, all live values, calculated values, alarm/event messages, parameters, and settings in a number of graphical displays
Full proving control, which allows the operator to select a liquid meter run for proving, visualize the proving process on the screens, and generate a prover report
Full sampling control