San Leon's shares rose after announcing the completion of its first vertical fracture stage in the Rogity-1 well on the Braniewo S Concession in Poland's northern Baltic Basin.The first stage was performed in the oil-bearing, tight Cambrian quartzite sandstones at the bottom of the well as part of a three stage vertical hydraulic Fracture Stimulation Programme.Temporary production tubing is being run to facilitate a short-term flow test and build-up test over the next four weeks to test the Cambrian.The company said the objective of the first fracture was to understand the frackability and production potential of the tight Cambrian sandstones. It is anticipated that any future development would be with multi-staged fracked long offset horizontals. San Leon has mapped a large Cambrian structure at the Rogity-1 well, which the company is analysing as a sweet spot for oil production via natural fractures.It is the first frack of a three stage programme in the Rogity-1 well as part of the recently signed farm-out agreement (FOA) with Wisent Oil & Gas. Wisent will fully fund the costs of thep and any subsequent testing in the well. "We are excited to have executed the FOA with Wisent and look forward to working with them on the proving the liquids potential of the lower Silurian in Braniewo S concession," said Executive Chairman, Oisin Fanning. "The primary target for this vertical fracture stimulation programme is the lower Silurian shale oil potential which has huge upside reserve potential across the eastern Baltic Basin." Shares were up 0.70% to 5.79 at 09:24 on Monday.RD