An operation to improve the flow of oil at the Horse Hill site in Surrey failed to return production volumes quickly to initial peaks.
Production figures for November 2020, published today, showed oil production reached 483m3, or 409 tonnes or 101 barrels a day (bpd).
This was less than half the volume in April 2020, the first full month of official production, when Horse Hill produced 1160 m3 (or 981 tonnes or 243 bpd).
Production in November was more than double that of October (233m3 or 47 bpd). That was when official production fell to its lowest level so far during a workover of the Horse Hill-1 well.
That operation reperforated the Portland section, inserted a simplified production tubing string and set the downhole pump deeper to “increase pumping efficiency”.
At the start of that work, UKOG’s chief executive, Stephen Sanderson, said the company looked forward to “the resumption of stable oil production at Horse Hill as soon as possible”.
The company announced the completion of work on 5 November 2020. A series of production optimisation trials, expected to last several months, followed the intervention, UKOG said.
Waste water and gas
In November, the production of formation or waste water resumed at Horse Hill after a month’s break in October. The volume, 188m3, was just above September (179.6m3) but below levels in June-August, when the average each month was 215m3.
Horse Hill intends to convert the HH-2z well into a water reinjector to avoid the need to remove formation water by tanker for processing.
The figures show that waste or associated gas produced in November (10.21 tonnes) was up on October (4.28 tonnes) but lower than the period March-September, when the average monthly was 20.76 tonnes.
The volume of gas burned in a flare at Horse Hill also rose in November (9.54 ksm3) but remained below the March-September average (19.4 ksm3).
An application to vary the environmental permit for Horse Hill shows the site intends to continue to incinerate waste gas up to 10 tonnes a day. (More details on DrillOrDrop soon.) UKOG previously said that waste gas from its Weald sites would be used as fuel for sites, with the surplus used to generate electrical power exported to the National Grid.