It is one of two horizontal wells which will establish valuable production from the conventional Portland oil pool, UKOG highlighted.
These wells, as horizontals, will be exposed to more of the reservoir and as such are expected to flow at significantly higher production rates than the 362 barrels of oil per day measured whilst testing the vertical Portland section in the current Horse Hill well.
UKOG, the largest stakeholder in Horse Hill with 85.635%, said it expects that HH-2 will be put into long term production by the end of 2019.
Stephen Sanderson, UKOG chief executive, described the well spudding as “another landmark milestone’ for the project.
“We are confident that the meticulously planned HH-2/2z operation, the first of two planned horizontal wells in the Portland oil pool, leaves little to chance.
“We look forward to a safe and successful drilling campaign and to the realistic prospect of HH-2/2z delivering a significant increase in UKOG's net oil production and associated revenues before the end of 2019."
The drill plan in more detail
UKOG detailed that the programme will start with a vertical pilot hole, referred to as HH-2, down to a depth of around 3,000 feet.
The horizontal well, referred to as HH-2z, will then be drilled out horizontally to include around 3,200 feet through what‘s believed to be the most oil-productive part of the Portland reservoir.
It all, some 5,800 feet of drilling is expected to take place to deliver the well.