Serica Energy has 5% working interest in the well.

Drilled to a total depth of 2,825 metres sub-sea, oil was encountered in fractured and brecciated cavernous Upper Jurassic carbonates.

About 26 degree API oil generated to surface with the drilling fluids during the course of drilling and well control operations.

Following this, a testing programme was conducted which confirmed the presence of oil. The company said that not all of the objectives of the testing program could be achieved, most probably because of the significant reservoir damage suffered during the earlier well control operations.

Therefore, further evaluation of the drilling and testing results is required before any definitive conclusions can be drawn, the company claimed.

The well will now be plugged and abandoned and the Noble Paul Romano semi-submersible rig will be released.

Serica chairman and CEO Tony Craven Walker said: "The SM-1 well has provided some valuable information regarding the future prospectivity of the Sidi Moussa Licence. The presence of good quality oil encountered by the well is encouraging for the remaining prospects on the licence and further tests on the oil samples taken will help determine the provenance of the oil which in turn will aid the identification of optimal locations for potential oil accumulations."