Prospects of Lithuanian Silurian shale gas, Baltic sedimentary basin

The Baltic sedimentary basin contains numerous hydrocarbon fields in Lithuania. The Lower Silurian shales are considered as potential for shale gas exploration. The thickness of shale units within the oil window ranges from 115 to 180 m in west Lithuania. The average total organic carbon (TOC) content of the Lower Silurian shales is about 1.0–1.2%, with an elevated content averaging 6.7% in the Aeronian black shales. The organic matter (OM) is Type II kerogen. Pyrolysis analysis shows moderate thermal maturity parameters; Tmaxis from 428 °C in central Lithuania to 455 °C in the west of the country, implying the oil generation stage. It is concluded that the burial conditions were favorable for oil generation, while the gas potential of Silurian shales is rather limited