UK Oil & Gas Investments PLC (LON:UKOG), which led the consortium that gave us the Horse Hill well, has outlined drilling plans that could help turn the southern Home Counties into a new hotspot for hydrocarbons.
Known as the Gatwick gusher because of its proximity to Britain’s second-largest airport, Horse Hill confounded the sceptics by producing crude in far greater quantities than had been expected.
Oil at a rate of 1,700 barrels a day came from three discrete layers in what’s called the Kimmeridge limestone.
That was far more than had been anticipated. The only problem was the testing lasted hours, rather than days or weeks.
UKOG won't return to Horse Hill for a whie. Instead, it plans to test an analogue - that’s an area with identical geological characteristics Horse Hill.
And it is hoping to add credence to a theory that could utterly transform the understanding of the geology of a large swathe of England.
Over the last two to three decades around 30 wells have been drilled into the Kimmeridge limestones of the Weald Basin.
The Kimmeridge rock of the Weald underlies the south and south-eastern corner of the country and was host to the Horse Hill crude.
However those 30 wells never tested for oil as the sedimentary rock was thought to lack the porosity required to host it.
What the experts suspect is the Kimmeridge at Horse Hill is naturally fractured, allowing oil to accumulate that when accessed flows easily to surface under its own steam.
If this model holds up then there would be no need for fracking to release this hydrocarbon bounty.
Sometime in the first-half of next year UKOG will move 11 miles along the road from Horse Hill to the PEDL234 licence area to drill the Broadford Bridge-1 well.
It will test the same Kimmeridge limestones discovered at Horse Hill.
Success here would start to suggest our theorising geologists are indeed correct about the make-up of the Weald Basin and, specifically, the fractured rock model.
However UKOG probably won’t be the first cab off the block as a number of rivals are planning similar exploration programmes.
In fact there are six wells slated to be drilled on or around Horse Hill with drilling at one, Brockham, having got underway just before Christmas.
Owner Angus Energy Plc (LON:ANGS) will first go into the Portland sandstone, host to a known oil play, before then pushing on into the Kimmeridge.
There is no guarantee that Brockham will enjoy identical geology to Horse Hill – but there is a suspicion it does; well more than that.
It is a hunch based on drilling carried out by BP (LON:BP), which used to own the Brockham licence.
One of Angus’ field partners, a firm called Doriemus, commissioned the consultant Nutech to make a comparative analysis of the Horse Hill-1 well and Brockham-1, sunk by BP in 1987.
It is too early to definitively assert this, but Angus believes the maturity and fracture analysis of the two have striking similarities.
The quantum of oil in the vicinity Gatwick could be mind boggling if the initial Horse Hill results are replicated with follow-up drilling.
The Kimmeridge reservoirs of PEDL234, for instance, are estimated to be host to 1.7bn barrels of the blacks stuff; Horse Hill itself may be host to up to 1bn barrels.
Those two licences alone would be internationally significant.
It has to be stressed that these are guesses based on the geology being absolutely as expected and the Kimmeridge being as prevalent as thought.
There are a whole host of other assumptions too that make this a bit of a finger-in-the-air exercise.
Anyway, success would throw up a huge conundrum. Does the UK, which is looking for energy independence, drill areas of outstanding natural beauty to unlock the oil?
The backlash could be interesting as you might see an unlikely alliance between the middle-class Nimbies of the southern stockbroker belt and the rent-a-protestors of the environmental movement.
Below is the schedule in full
There are six new wells planned for in and around Horse Hill. South East of England, which will uncover whether there really are billions of barrels of untapped oil in the region’s Weald basin.
Two wells are planned on the site itself; one is a sidetrack of the existing well, the other brand new.
One well at Holmwood, Horse Hill’s neighbour, will be drilled by Europa Oil & Gas (Holdings) PLC (LON:EOG), UKOG, Egdon Resources Plc (LON:EDR) and Union Jack Oil PLC (LON:UJO).
One well at Brockham: The Angus Energy sidetrack will test the Kimmeridge reservoirs.
UKOG will drill two new wells PEDL 234: Broadford Bridge well (first-half of next year); the timing of the second isn’t specified.