Incremental said Arpaci-1 was perforated and tested over a 4m interval, which had ambiguous gas indications on well logs, but resulted in the production of water only.

However, the test did confirm seismic amplitudes indicating the presence of gas bearing reservoir sands and, according to Incremental, is a valuable tool to steer future exploration and development drilling in the area.

Otto chief executive Alex Parks said the disappointing results from Arpaci-1 does not affect the overall commerciality of the Arpaci field, which was successfully appraised with the Arpaci-2 well.

The Arpaci-1 well was first drilled in 2006, but not tested due to adverse winter weather conditions.

The partners will now focus on re-drilling Apraci-2, about 50m northeast of Arpaci-1.

Arpaci-2 was drilled earlier this year and encountered gas bearing sands at unusually high pressures. Due to safety concerns, the well was plugged and abandoned.

Arpaci-2 will be re-drilled as Arpaci-2A at 30m offset to the north of the original well and is the last well to be drilled in 2008 as part of a campaign to prove up significant volumes of gas.

Incremental has 55% in the Edirne licence, Otto Energy holds 35% and a Turkish company, Petraco, holds the remaining 10%.