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 – 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 Zechstein main dolomite. The total resources of these 2 fields as of the end of 2019 amounted to 14,753.87 million m3. Nowadays, the exploitation is being carried out only from Cychry field and it was equal 21.58 million m3 in 2019. The chemical composition of gas from 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 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: Dariusz Brzeziński, Martyna Czapigo-Czapla