UK Oil & Gas PLC said Monday that Horse Hill Development Ltd completed the final Portland flow test at the Horse Hill oil discovery in Surrey, England.

UK Oil & Gas owns a 46.7% stake in Horse Hill, the operator of the HH-1 Kimmeridge and Portland oil discovery. Earlier in August, it raised its interest to 71.9% after buying out Gunsynd PLC and Primorus Investments PLC and Solo Oil PLC, however the transactions are not yet completed.

The company said that all Portland objectives have now been reached. A re-perforation programme targeted 114 feet of oil pay, added 14 feet of new pay. Following re-perforation, well productivity increased by up to 65%, the company said.

Independent oil consultants Xodus Group carried out an analysis of flow and pressure data which found that HH-1 could achieve a forecast sustainable initial pumped rate of around 362 barrels of oil per day.

"Following a final long duration pressure build up test, preparations for the primary Kimmeridge EWT are now underway," UK Oil & Gas said.

Chief Executive Officer Stephen Sanderson said: "We are delighted that the HH-1 re-perforation and optimisation programme has resulted in the forecast sustainable Portland production rate of 362 barrels of oil per day, which significantly exceeds our initial test programme expectations.

"This high rate, together with our economic modelling, strongly indicates that the HH-1 Portland vertical well is commercially viable and robustly economic at the lowest observed sustainable test rates and the predicted future sustainable production rates."

All the other partners in the Horse Hill development, Solo Oil, Gunsynd, Primorus Investments and Alba Mineral Resources PLC also noted the announcement. Alba currently owns an 11.8% stake in Horse Hill, the only partner who has not sold its interest to UK Oil & Gas.