Measurement System
The scope of operation of EuRoPol GAZ s.a., as both the owner and operator of the Polish part of the System of Transit Gas Pipelines is reduced to rendering gas transport services. For settlement of these services it is necessary to determine precisely the quantities of transported gas and its other parameters at the entry point to the Polish stretch and at all exit points to commercial and process consumption points; fuel gas for in-house purposes is drawn from the latter.
The Metering Station that determines both the quantity and parameters of gas at the entry to the Polish part of SGT is located within the area of the Kondratki Compressor Station, close to the Polish-Belorussian border. Continuous automated gas flow measurement was provided by use of two separate measuring systems for each of the transit pipeline lines. Each of these systems is equipped with insulation assemblies on the input and output side, sets of filters and six DN600 measuring strings. Each measuring string is equipped with the UHF gas meter (basic measurement) and a constriction flowmeter (control measurement). Flow measurements are adjusted as a function of pressure, temperature, chemical composition and density of natural gas. Moreover the metering station conducts chromatographic analysis of gas measurement of hydrogen sulphide contents in gas, dew point temperature, specific heat, calorific value and Wobbe index.
Measuring systems of the same standard have been designed for the points of gas input to the national gas system located in Włocławek and Długa Goślina and also in Lwówek (owned by PGNiG S.A.). The operating Systemic Pressure Reduction and Measurement Station in the area of the Włocławek Gas Compressor Station is currently equipped with the first line’s measurement system that consists of three DN300 lines and other process infrastructure, as in the Kondratki Measurement Station. The last measurement station (owned by WINGAS company) that confirms the quality of the transport service delivered (transit gas transmission to Germany) is situated within the area of the Mallnow gas compressor station, on the German side, some 12 km behind the Polish-German border.
Current information on parameters and quantities of the flowing gas, after processing, is conveyed to adequate levels of the System’s management and archivised in a way that has been agreed upon.
The standard of equipment in the measuring stations, systemic requirements for quality and accuracy of measurements as well as transfer of measurement data have been agreed at the level of international groups of scientific and technical cooperation and approved by authorised representatives of the parties of transmission contracts.
Similar settlement principles apply to the fuel gas (for the turbines) and for own needs of the compressor stations. This gas charges the costs of the systemic transport and thus is subject to a very precise quantitative settlement, conducted in the pressure reduction and measurement stations for gas for in-house needs, located on each compressor station’s process pipelines. Requirements for measuring equipment and software of these stations are equivalent to those for the transmission settlement metering stations.
Control System
The Polish stretch of the Yamal–Europe transit gas pipeline is controlled and managed by means of the SCADA [Supervisory Control and Data Acquisition] system – Viewstar 750. The system has been built and implemented in phases, together with construction of successive compressor and metering stations and installing the operational software. Ultimately it will supervise and control the following facilities:
- 5 gas compressor stations with connection assemblies (ZPT);
- 10 shut-off and relief valve systems (OZZU) at the compressor stations;
- 24 shut-off and relief valve systems (ZZU) along the pipeline;
- Kondratki Metering Station;
- Włocławek Metering Station;
- Lwówek Metering Station;
- Długa Goślina Metering Station (2nd Line).