Smart Metering for LACT Units

With the focus in the oil & gas industry shifting from exploration to optimizing current operations, Lease Automatic Custody Transfer (LACT) units come forward in increasing efficiency of the oil transfer and providing more accurate accounting, collected at the SCADA level.

The system is an improved-accuracy fiscal metering system for LACT units, able to measure, compute, and store data on oil:

  • Volume
  • Quality (density, viscosity, humidity)
  • Flow
  • Pressure and pressure drops
  • Temperature

The system is made of a PLC (B600, B500, or combination of B400 HMI with B200 modules), high-accuracy analog input modules (AI08041 or AI02041) with just a 0.025% margin of error, and a specialized I/O module with integrated algorithm for LACT units (DA03011 / DA01011). The use of the latter modules ensures calibration unit control and the reception of the signals from flow meters in a timely and accurate manner.

To the system could be connected external devices, like a printer, for example, via USB ports, monitors via VGA (B600) or DVI (B500) interfaces on the CPU modules.

The entire visualization process for the system is implemented in one project together with the preset functions. All the information from the REDUL BX00 controllers is communicated to the redundant servers and to the LACT unit workstation. The system could be connected to most major SCADA systems available on the market.

When using B200 I/O modules, additional protective seals could be added, to protect against unauthorized module replacement.


Since this is a single-channel measurement system (meaning a replication of the system can be performed without an additional controller backup), controllers from the older series (B600, B500) can be used, as well as a combination of CPU B400 and B200 modules. The system is based on the REDUL B600 and REDUL B500 series and employs the CU00071 central processor unit, which has USB ports and VGA (B600 series) and DVI (B500) outputs to connect a touchscreen display. In the B400 + B200 combination, the data display and input are executed directly from the REDUL B400.

The entire visualization process for the system is implemented in one project together with the preset functions.

All the information from the REDUL BX00 controllers is fed to the redundant servers and the LACT unit workstation.

The use of DA03011 (DA01011), with its customized built-in software, ensures calibration unit control and the reception of signals from flow meters.

The design of the B200 I/O module provides a protective seal against unauthorized replacement.

For unification purposes, the system’s automation and safety control cabinets can also be based on the REDUL BX00 controller.

Main System Functions

  • Computation of oil volume and mass for each measurement line for the entire system
  • Automatic measurement of process parameters
  • Automatic measurement of oil quality parameters
  • Display, indication, logging, and archiving of measurement results
  • On-site use of calibration devices to control and check flow meter metrological parameters without interfering with the technological processes
  • Providing personnel with a user-friendly interface for equipment access and operation

Main Workstation Functions

  • Access control, authentication, and authorization of clients logging into the system
  • Visualization of the technological process and the overall equipment status via flowcharts and light and sound event alarms
  • Fast-tracking of emergency and pre-emergency events (audio and video data)
  • Review of event logs
  • Manual input of current oil parameter values based on sample-taking
  • Creation of reporting documentation (operational, daily, hourly, and shift reports, measurement logs, oil acceptance acts, and oil quality passports)
  • Report archiving
  • Logging into the system with the ability to modify the maximum permissible values, as indicated in the system design
  • Generation of control commands and indication of calibration process status
  • Gathering of diagnostic data on the system hardware status and basic and application software status

Technical Specifications (Depending on the System’s Built-in Software

SpecificationsConfiguration optionsMeasurement lines12
Electrical supplyCurrent typeDC
Operating environmentAmbient temperaturesfrom +10°C to +40°C
Relative humidity35–70 %
Atmospheric pressure range84–106.7 kPa
Basic metrological specificationsRelative error of input signal measurement
DC <0.025%
In the frequency mode<0.01%
In the pulse count mode<1 pulse
Absolute error of density calculation<0.01 kg/m3
Relative error of software and data-processing algorithms
Oil mass calculation<0.002%
Oil volume calculation<0.0004%
Working flow transducer ratio<0.025%
Relative error of measurement of
Oil gross weight<0.05%
Oil net weight<0.05%
Oil volume<0.025%