The Perth-based junior said this morning that the drilling crew has been evacuated, with work expected to resume next week, subject to better weather.

Since the company’s last update, the well has been plugged back to a depth of 1224m and perforated between 1216m and 1222m in preparation for acidisation and testing of this zone.

“Pre-acidising swabbing from the zone recovered water as expected but before acidising could take place, weather conditions deteriorated further and the well was suspended for safety reasons,” Eureka said.

“When weather conditions allow, pumping of water from the zone will resume, followed by acidising and pump testing.”

Last week, Eureka reported that re-interpretation of wireline logs indicated this 5.5m zone in the Garzan Formation had relatively high porosity and may be capable of producing oil.

Koyunlu-1 is about 17km south of the West Raman oil field (original oil in-place 1.5 billion barrels) in southeast Turkey’s major oil-producing region.

It was located to test the eastern portion of a structure with similarities to the West Raman and Raman field structures. The target reservoirs are in the formation that hosts oil in the nearby Raman fields and numerous other oil fields in the region.

The oil recovered from the Garzan Formation in the Raman fields is relatively heavy (13-18 degree API gravity) and the oil at Koyunlu-1 is likely to be similar. This oil is readily saleable at a small discount to standard Middle Eastern crude prices.

The structure could hold recoverable reserves of between 2 million barrels (MMbbl) and 204MMbbl (31MMbbl P50). The wide range in reserve potential reflects the relatively poor seismic control of the host structure.

Eureka has acquired farm-in rights to earn a 20% interest, together with an option to increase its interest to 45%, in two adjoining exploration licences covering about 500 square kilometres in southeast Turkey.

The Koyunlu-1 well is the first of two farm-in wells to be drilled in the licences, which are owned by Turkish exploration and production company Arar Oil and Gas.