Plans to test the Horse Hill exploratory oil well near Gatwick Airport came a step closer this week.
The Environment Agency issued a variation to the site’s mining waste permit, allowing the operator, Horse Hill Developments Ltd, to test whether oil will flow and at what rate. Fracking will not be allowed under the permit changes.
The company has also been issued with a permit to manage and dispose of naturally-occurring radioactive material. This includes conditions that require liquid and solid wastes to be disposed within three months and limit the amount of waste to be stored on site.
The Horse Hill-1 well was drilled at the end of 2014. One of the companies with an interest in it, UK Oil & Gas, said the test would assess the oil-bearing Upper Portland sandstone reservoir and the Kimmeridge limestone reservoirs beneath the Portland. It expected the tests would happen “in the coming months”.
UKOG’s executive chairman, Stephen Sanderson, said:
“The consent to flow test is a major milestone for the Company. The flow test’s outcome will help UKOG shape its future Portland oil development activities and materially advance its knowledge and growth in the Kimmeridge tight oil play within our licences and the wider Weald Basin.”
Frack Free Surrey said:
“How ironic that they got this permit on the day the UN climate summit started – and the day after many Surrey residents were marching in London in defence of the climate.”
“Frack Free Surrey is opposed to both conventional and unconventional extraction of oil and gas. Scientists say that to avoid hitting a catastrophic climate tipping point, we need to keep 80% of all known fossil fuels in the ground. Now is the time to switch investment into renewable energy, not extract the last dregs of dinosaur fuel out of the ground.”
Flow testing details
In a press release, UKOG said:
“The test will provide the necessary reservoir engineering data to enable the company to assess the commercial viability of the Portland sandstone oil discovery, which encountered significant oil shows whilst drilling, and to further advance the “proof of concept” process for the Kimmeridge tight oil play, which has previously been shown to flow oil elsewhere in the same formations of the Weald Basin, at Balcombe some 10 miles to the south.”
The tests, which still need consents from the Oil and Gas Authority and Health and Safety Executive, are described on UKOG’s website (link). It says the single Upper Portland sandstone layer and a succession of limestone layers will be perforated to allow oil to flow into the wellbore.
“Flow will pass up the well through a valve arrangement, known as a “Christmas tree”, then on into the flow testing equipment at the surface.”
“Oil and water will be transported from site via road tankers, to a trans-shipment point and to a licensed disposal site respectively. Flow testing will be of short duration, the objectives being to establish a stable flow rate, sample reservoir fluids and then shut in the well to record pressure. The number of road tanker loads will be minimised during the flow test programme.”
“The maximum amount of time to execute the entire flow testing programme is currently estimated at 30 days, with potential for reduction. This includes mobilisation, setting-up and removal of all related equipment from the well site. Heavy good vehicle movements will be arranged to minimise road traffic. During the programme it is estimated that the well would be flowed for no more than 10 days in total.”
The Environment Agency said it had considered the opinions about the permit applications raised in a four-week consultation. A spokesperson said:
“We would like to thank all those people who responded to the consultation. Since the consultation period closed, Horse Hill Developments Limited has provided additional information to clarify some of the aspects of their application for flow testing.”
“After considering all of the information available and completing our assessment we are confident that the environment and people will be protected. Environment Agency officers will now ensure compliance with these operating conditions during the next phase of works.”