High nitrogenous natural gas
Up to the present, in Poland 2 high nitrogenous natural gas (HNNG) fields characterized by the nitrogen content over 90% have been documented – the Cychry and Sulęcin fields, located in the Polish Lowlands. HNNG is a raw material of a quality good enough for the production of a liquid nitrogen but it is more often used to the adjustment nitrogen content in the natural gas pipelines of the domestic distribution network. However, its utility for the latter purpose is smaller than that of gas from the fields with lower nitrogen content but not smaller than 70%, which are not differentiated as a separate group of HNNG fields.
Two documented HNNG fields in Poland – Cychry and Sulęcin – occur in the Zechstein Main Dolomite. The total resources of these fields as of the end of 2021 amounted to 14,692.82 million m3. Nowadays, the exploitation is being carried out only from the Cychry field and it was equal 28.05 million m3 in 2021. The chemical composition of gas from the Sulęcin field is as follows: 97.60% of nitrogen, 1.60% of methane, 0.40% of ethane, 0.36% of heavy hydrocarbons and 0.04% of carbon dioxide; whereas gas from the Cychry field contains: 91.00% of nitrogen, 5.20% of methane, 1.30% of ethane and 0.22% of carbon dioxide. The resources of these two fields are presented in Table 1.
At present, exploitation of HNNG is limited to Cychry field only.
Prepared by: Martyna Czapigo-Czapla, Dariusz Brzeziński