The Horse Hill discovery well, near Gatwick airport, has flowed light oil to surface from the one of the intervals within its deeper hybrid oil zone.
An initial instantaneous flow of fluid, approximately 50% oil and 50% water, was measured at a rate of 700 barrels per day from the Lower Kimmeridge limestone interval, before a subsequent seven hour test period measured a flow rate of 463 barrels of oil per day.
The flow during the seven hour test comprised 99% oil.
Neil Ritson, chairman of Solo Oil (LON:SOLO), a 6.5% stakeholder in the project, described the result as “extremely encouraging” and highlighted that the results have exceeded expectations for natural flow from the Kimmerage limestone.
The Kimmeridge limestone intervals are part of hybrid play in the deeper part of the Horse Hill well, which has been the subject of a number of very large resources estimates in recent months.
In a separate statement, UK Oil & Gas (LON:UKOG) executive chairman Stephen Sanderson said the successful flow testing was a “very significant” event.
“Importantly, tests so far show oil has flowed to the surface under its own pressure and has not, so far, required artificial lift.
“The flow test, the first ever in the Lower Kimmeridge limestone within the Weald basin, provides proof that significant quantities of moveable oil exist within the Kimmeridge section of the well and can be brought to surface at excellent flow rates.
“In this case from a vertical well with minimal stimulation.”
Sanderson further highlighted that future plans would involve horizontal wells and conventional reservoir stimulation techniques so flow rates could be even higher in future wells.
Another test will be carried out on the Lower Kimmeridge today, starting at 7:00am, and subsequently other parts of the well will also be tested.
At the Lower Kimmeridge an 80 foot zone was tested at a depth of 900 metres. An Upper Kimmeridge zone, located at a depth of 840 metres, will be tested and the shallower Portland sandstone reservoir, at 615 metres, will be tested too.
Sanderson told UKOG investors that the Horse Hill partners now intend to start the process for regulatory permitting, as they seek to demonstrate sustainable commercial production.
UKOG has a 20.1% interest in Horse Hill.