RNS Number : 3675K
UK Oil & Gas Investments PLC
06 July 2017


UK Oil & Gas Investments PLC

("UKOG" or the "Company")


Fractures, Live Oil Seeps, Shows in Kimmeridge Limestone KL2-KL4 Cores at Broadford Bridge-1 Exploration Well, PEDL234 Licence, Weald Basin, UK




·      Conventional coring programme successfully executed, 13 cores totalling 554 ft recovered


·      12 continuous cores totalling 493 ft taken through KL3-KL4 fractured limestone and shale reservoir section, one 61 ft core taken in KL2 reservoir target


·      Mobile light oil seeps and oil staining at top KL4. Elevated wet gas readings and oil recovered from drilling fluid throughout cored interval from 4018 ft to base KL2 at 4779 ft measured depth ("MD"), a total possible gross oil-bearing zone of 761 ft MD. KL1 not yet reached


·      Kimmeridge geological section and observed wet gas readings near identical to Horse Hill-1 KL3 and KL4 oil discovery 27 km to NE, where oil flowed at 1365 bopd from KL3 and KL4


·      Significant lost-circulation zones at top KL3 and base KL2 indicate presence of well-developed and spatially connected natural-fracture system; abundant fractures in limestone and shales observed throughout cores


·      Now drilling ahead to KL1 target expected at around 5100 ft MD. Electric logging and flow testing to follow shortly


UK Oil & Gas Investments PLC (London AIM and NEX: UKOG) is pleased to announce that it has successfully completed an extensive conventional coring programme at its 100% owned Broadford Bridge-1 ("BB-1") exploration well located in licence PEDL234. 13 cores totalling 554 ft were successfully recovered throughout the Kimmeridge Limestone 2 ("KL2"), KL3 and KL4 naturally fractured reservoir target zones. Coring operations were carried out by ALS Corpro, globally recognised experts in this specialised sector.


Twelve continuous cores, totalling 493 ft, were taken to capture the entire KL3 and KL4 reservoir target zones. The continuous cored section includes a series of interbedded limestones and shales above the KL4 reservoir zone and a complete section of highly organic-rich black calcareous shales and thin limestones lying between KL3 and KL4. A single 61 ft core was recovered over the entire KL2 reservoir target, the first core through this section in the UK.


The cored and drilled section to date indicates that the Kimmeridge geological section at BB-1 is, based on data collected from the well to date, almost an exact mirror image of the Company's Horse Hill-1 ("HH-1"), oil discovery well, 27 km to the NE (UKOG interest 31.2%).


As previously reported, mobile light oil was observed seeping from fractured KL4 calcareous shales and limestones within the upper section of the KL4. Mobile light oil was also consistently recovered from the drilling fluid or "mud" throughout the cored and drilled section from 4018 ft MD to 4779 ft MD (761 ft), the current depth just below the base of KL2. Wet gas readings were recorded throughout the cored interval, further indicating the presence of oil within the section. Wet gas readings consistently mirrored those seen in the HH-1 KL 3 and KL4 oil discovery well, 27 km to the NE, which flowed oil at a stable aggregate rate of 1365 barrels of oil per day.


The combination of direct and indirect oil indications observed is strongly indicative that the well has encountered a total possible gross oil-bearing zone of 761 ft MD. It should be noted that as the deeper KL1 reservoir target, lying around 300 ft below KL2, has not yet been reached, it is possible that the gross possible oil-bearing section could further increase.


Abundant fractures were seen in both limestones and calcareous shales throughout the core. Oil was seen seeping from several fractures in the upper cored section. Two significant lost circulation zones ("LCZs") were observed whilst coring.


The LCZs encountered demonstrate that the BB-1 Kimmeridge section contains a well-developed and spatially connected natural fracture system. Evidence of natural fracturing from HH-1, the recent Brockham X4z and Balcombe-1&2 wells (in which UKOG has no interest) support the Company's hypothesis that the Kimmeridge limestones and shales are fractured on a basin-wide scale within the Weald.


Conclusions to Date


The initial observed presence of mobile oil in fractured Kimmeridge limestone and shale at BB-1, possibly over a 761 ft plus vertical section, lying within a geological feature without any observed conventional structural or stratigraphic trapping configuration, is in the Company's opinion supportive that the well provides "proof of concept" that the Weald contains a significant continuous oil deposit.


The observation that the Kimmeridge geology and hydrocarbon shows at BB-1 are near identical to the HH-1 oil discovery, 27 km to the NE, provides further supporting evidence that both wells may penetrate the same oil accumulation.


The significant vertical gross oil-bearing section within both fractured limestones and shales at BB-1 also likely supports the HH-1 flow test conclusions that oil production was derived from a much larger reservoir "tank" than the two individual KL3 and KL4 limestone units tested.


Forward Operations


The well is now drilling ahead towards the remaining KL1 objective and then to its planned total measured depth of around 5740 ft. Following completion of the drilling an extensive electric logging and formation imaging programme will commence. The logging programme will be carried out by Schlumberger, a global leader in the field. Logging and well completion, expected to be completed over the next few weeks, will be followed by an extensive flow testing programme.


Stephen Sanderson, UKOG's Executive Chairman commented:


"The highly successful coring programme continues to provide supporting evidence that BB-1 has possibly encountered an extensive oil-filled natural fracture network, sitting within both the Kimmeridge Limestones and oil generative Kimmeridge shales.

The observed light mobile oil, together with the indications of a possible thick gross oil zone within a geological feature without any conventional oil trapping configuration, provides further "proof of concept" that the Kimmeridge of the central Weald may contain an extensive, thick, continuous oil deposit. This is an important milestone for the Company.

I look forward to the following electric logging and flow test programmes, which will hopefully provide both further "proof of concept" and demonstrate the commerciality of BB-1."

About BB-1


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 ("KOGL"). 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. 


Qualified Person's Statement


Stephen Sanderson, UKOG's Executive Chairman, who has over 35 years of relevant experience in the oil industry, has approved the information contained in this announcement. Mr Sanderson is a Fellow of the Geological Society of London and is an active member of the American Association of Petroleum Geologists.


For further information, please contact:


UK Oil & Gas Investments PLC

Stephen Sanderson / Kiran Morzaria                                     Tel: 01483 243450 


WH Ireland (Nominated Adviser and Broker)

James Joyce / James Bavister                                                   Tel: 020 7220 1666


Cenkos Securities PLC (Joint Broker)

Nick Tulloch / Neil McDonald                                                   Tel: 0131 220 6939


Square 1 Consulting (Public Relations)

Brian Alexander / David Bick                                                    Tel: 01483 243450 / 020 7929 5599




heavy gauge steel tubing designed to line the wall of a well. The casing provides a safe controlled space in which the drill pipe and bit can operate in isolation from conditions in overlying rock units. The steel tubing is bonded to the surrounding rock by impermeable concrete, known as "cement"

core or coring

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 bit. Core is normally cut in 30 feet lengths, or multiples of 30 feet, and normally with a diameter of 3.5 or 4 inches. Core is taken in petroleum reservoir rocks for detailed laboratory analyses of petrophysical and geomechanical parameters

continuous oil deposit or resource deposit

a petroleum accumulation that is pervasive throughout a large area, which is not significantly affected by hydrodynamic influences (i.e. the buoyancy of oil in water) and is not trapped by structural or stratigraphic geological conditions. The deposit, in contrast to conventional accumulations, has therefore not accumulated by the migration of petroleum over medium to long distances. The petroleum in such deposits is found within, or immediately adjacent or close to, the  pore spaces where the petroleum is generated, i.e. those pore spaces lying within petroleum source rocks containing organic rich compounds (kerogen) that, when heated over geological time, transform into petroleum. These accumulations are generally associated with organic-rich shales such as the Kimmeridge Clay Formation. Such accumulations do not generally contain significant volumes of free, mobile formation water and therefore have no observable hydrocarbon-water contacts. The extent of the accumulation is generally defined by the limit of where burial depths have been sufficient to transform organic matter within the petroleum source rock unit into petroleum.


a discovery is a petroleum accumulation for which one or several exploratory wells have established through testing, sampling and/or logging the existence of a significant quantity of potentially moveable hydrocarbons


a sedimentary rock predominantly composed of calcite (a crystalline mineral form of calcium carbonate) of organic, chemical or detrital origin. Minor amounts of dolomite, chert and clay are common in limestones. Chalk is a form of fine-grained limestone

lost circulation zone (LCZ)

a zone of highly porous and permeable rock or voids directly intersecting the wellbore into which drilling fluid can escape. Commonly LCZs occur in extensive open fracture networks, voids or vugs within limestones and  highly porous and permeable sandstones.

naturally fractured reservoir

a fractured reservoir contains open and usually connected cracks or fissures within the rock matrix; fractures can enhance permeability of rocks greatly by connecting pore-spaces together; naturally fractured reservoirs have been created over geological time by nature, not man-made via hydraulic fracturing


a fissile rock that is formed by the consolidation of clay, mud, or silt particles, and that has a finely stratified or laminated structure. Certain shales, such as those of the Kimmeridge Clay, often contain a significant proportion of organic material, which when subject to increasing temperature and pressure over geological time transform into petroleum (known as petroleum "source rocks")

step-out well

a well specifically designed to determine the lateral extent of a discovered hydrocarbon accumulation or play

wet gas

natural gas, predominantly consisting of methane (C1), ethane (C2) and propane (C3) but also containing the longer molecular chain natural gases butane and iso-butane (C4), pentane and iso-pentane (C5). The C4 and C5 gases are created during oil-generation within a petroleum source rock unit when oil is thermally cracked. At Horse Hill these natural gases lie in solution with the oil in the KL3 and KL4 Kimmeridge Limestone reservoirs (i.e. solution or associated gas and not as a separate free-gas phase).


UKOG Licence Interests


The Company has interests in the following ten UK licences:



UKOG's Interest

Licence Holder


Area (km2)


Avington 1



UKOG (GB) Limited

IGas Energy Plc


Field in stable production

Baxters Copse 2



UKOG Weald Limited

IGas Energy Plc


Appraisal/development well planned; licence extended to 2018

Broadford Bridge 3



Kimmeridge Oil & Gas Limited 4

Kimmeridge Oil & Gas Limited 4


BB-1 drilling underway

Holmwood 3




Europa Oil & Gas (Holdings) plc


Holmwood-1 exploration well planned in 2017

Horndean 1



UKOG (GB) Limited

IGas Energy Plc


Field in stable production

Horse Hill 5



Horse Hill Developments Ltd 

Horse Hill Developments Ltd 


Submitted planning application for long term production tests and drilling of two wells

Horse Hill 5



Horse Hill Developments Ltd

Horse Hill Developments Ltd 


As above

Isle of Wight (Offshore) 3



UKOG Solent Limited

UKOG Solent Limited


Preparing drilling planning submission

Isle of Wight (Onshore) 2, 3






Preparing drilling planning submission

Markwells Wood 2



UKOG (GB) Limited

UKOG (GB) Limited


Submitted planning application for appraisal and field development



1. Oil field currently in production.

2. Oil discovery pending development and/or appraisal drilling.

3. Exploration asset with drillable prospects and leads. Contains the extension of the Godley Bridge Portland gas discovery and the site of the forthcoming Broadford Bridge-1 well.

4. UKOG has a 100% interest in Kimmeridge Oil & Gas Limited, which has a 100% interest in PEDL234.

5. Oil discovery with recently completed flow testing.

6. UKOG has a direct 48% interest in HHDL, which has a 65% interest in PEDL137 and PEDL246.

The information contained within this announcement is deemed by the Company to constitute inside information under the Market Abuse Regulation (EU) No. 596/2014.


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