UK Oil & Gas plc has announced it has successfully shut-off the source of formation water that entered an oil well at its Horse Hill site in Surrey.
The company said in a statement it had plugged a section of the horizontal HH-2z well, in what it described as a zone of open natural fractures. The statement said the work was carried out at the deepest part of the wellbore.
The statement also said since plugging, initial tests had “demonstrated a continuous flow of dry oil to surface”.
This confirmed the plug had “eliminated underlying formation water ingress into HH-2z, the company said.
According to the statement, half hourly flow rates had ranged from 10-778 barrels of oil per day (bopd).
UKOG’s chief executive, Stephen Sanderson, said:
“Such water shut-off operations are routinely undertaken in production wells.
“However, success, particularly in horizontal wellbores and where water ingress is via open natural fractures, is by no means guaranteed. Consequently, this is an excellent result for the Company as it has enabled HH-2z to flow dry oil to surface at encouraging initial rates.”
UKOG revealed the water problem just before Christmas 2019. It said on 19 February 2020 that work had begun to tackle the problem.
Today’s statement said the company expected the full clean-up of spent drilling and completion fluids in the wellbore would take “a number of weeks”.
It added: “further interventions are planned to help fine-tune and optimise flow from the well”.
Shares in UKOG fell at the start of trading but have since recovered. At the time of writing (10.48am), they were down 1.75% at 0.56 pence.
9/3 Share price corrected to pence in final paragraph