New information from the Sillaro-1 would be used to revisit the geological model, chief executive Michael Masterman said.

“We were expecting to replicate the results of the nearby ENI drilled Budrio-2 well which tested commercial flows in the Pliocene [but] our initial Sillaro-1 test has not replicated this result,” he said.

“However, Sillaro remains a prospective gas development prospect for Po Valley and we will suspend current drilling operations to take the time to more clearly understand how the Sillaro-1 results fit with the more promising results of ENI’s earlier discovery.

“Deviations of our Sillaro-1 well towards the previously successful Budrio-2 and Budrio-3 wells will be carefully evaluated over the coming weeks.”

Sillaro-1 perforated the target Pliocene zone (PL 2B) on two levels - 2,191.5 metres to 2,202 and 2,212m to 2,224m.

Well pressure was significantly higher than in Budrio-2, Po Valley said.

But the production test showed initial gas production at a rate too small to measure, and subsequently sand and water production. It appeared that there was water in levels of the thin beds and this water incursion had cut off gas production, the company said.

A separate test was being considered to assess if it was possible to isolate the water and produce dry gas.

The lower Miocene zone that logs had indicated was possibly gas-bearing was perforated from 2,490m to 2,520m and also tested negative due to tight sands, Po Valley said.

Sillaro-1 was not an optimal location for drilling the Miocene and potential for productive Miocene gas producing levels remains towards the location of the Budrio-6 well drilled by ENI in 1982, the company said.