UK Oil & Gas Investments PLC has announced that mobile light oil has been observed seeping from open natural fractures in Kimmeridge Limestone 4 core samples at its 100%-owned Broadford Bridge-1 exploration well, PEDL234 Licence, Weald Basin, UK.
The KL4 samples, at a measured depth of around 4080 ft, exhibit a strong oil odour plus the rock matrix is oil saturated and heavily oil stained. Wet gas readings also increased significantly at the top of the KL4. Both the KL4 and overlying shales exhibit a high degree of natural fracturing. Coring operations continue through KL4.
The well remains on schedule and under budget.
The 160 ft of core taken to date in the Upper Kimmeridge Shales and Limestones will be transported to Aberdeen today for initial rock sampling at the weekend, before extensive geological, petrophysical and geo-mechanical analyses will be carried out by COREX and Premier Oilfield Laboratories in the UK and USA.
Stephen Sanderson, UKOG's Executive Chairman commented:
"I am privileged and excited to have seen, smelt and touched the oil in the KL4 samples today, alongside UKOG's management and operations team. This is a significant and positive result at such an early stage in the well.
Whilst this is still early days, the presence of mobile oil within a Kimmeridge geological feature that has no structural oil trapping configuration, demonstrates that both BB-1 and Horse Hill-1 could be part of the same Kimmeridge continuous oil deposit. This oil deposit may therefore extend over 30 km from north to south across the Weald Basin.
We will now continue our coring and drilling programme and then move to an extended flow testing operation upon the grant of the remaining necessary regulatory permissions."
Coring is a drilling technique that involves using a doughnut-shaped drilling bit to capture or 'cut' a continuous cylinder-shaped core of undamaged in-situ rock. The core is captured in a steel pipe or 'core barrel' above the core bit. Core is normally cut in 30 ft lengths, or multiples of 30 ft, and in the case of BB-1 with a diameter of 4 in. Core is taken in petroleum reservoir rocks for detailed laboratory analyses of petrophysical and geomechanical parameters and of any hydrocarbons contained within the rock.
BB-1 is located near Billingshurst, West Sussex, within the 300 km² PEDL234 licence, in which the Company has a 100% interest via its ownership of the licence's operator, Kimmeridge Oil & Gas Limited. The well, an exploration step-out, is designed to penetrate four naturally fractured Kimmeridge Limestone units (KL1-KL4), the uppermost two units of which flowed at record rates in the Horse Hill-1 discovery near Gatwick Airport.
Importantly, to prove that the Kimmeridge Limestones lie within an extensive continuous oil deposit the BB-1 well was deliberately designed to test a feature with no structural closure at the KL1-KL4 horizons.
The forward plan is to continue to core the KL4 and KL3 target zones and then continue to drill 8 ½ in. diameter hole at a constant inclination of 54° to vertical. Further core may be taken in KL2. The planned overall horizontal deviation of the well is approximately 1 km. The Kimmeridge Limestones are expected to be encountered at a drilled depth of approximately 1250 - 1700 m, which equates to around 950 - 1200 m vertically below surface.
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/27062017/oil-seeps-from-kimmeridge-limestone-core-samples-at-broadford-bridge-1-kimmeridge-exploration-well/