UK Oil & Gas Investments PLC

("UKOG" or the "Company")

Operational Update

Horse Hill-1 Oil Discovery, Weald Basin, UK

Highlights:

· 150-day production flow-test and new drilling programme set to commence in late winter 2017/18

· Programme aims to confirm commerciality of Portland and Kimmeridge oil discoveries and gear-up for first permanent oil production targeted for early 2019.

· Drilling of HH-2 appraisal well as future producer to directly follow flow testing programme

· Permanent production consent application underway, submission to SCC expected in spring 2018

· Swift and successful eviction of protesters completed at Horse Hill site on 02 December

UK Oil & Gas Investments PLC (London AIM: UKOG) announces that it has been advised by Horse Hill Developments Ltd ("HHDL"), the operator of the Horse Hill-1 ("HH-1") oil discovery, in which the Company holds a 32.435% interest, that key contracts and the requisite funding commitments from all participants are in place to undertake the production flow testing and drilling campaign approved by Surrey County Council ("SCC") in October 2017. The 2018 programme is planned to commence directly upon the discharge of SCC's pre-commencement planning conditions, expected by the end of winter 2017/18. Environment Agency approval for the full programme was granted in September 2017.

Horse Hill Oil Discovery

The HH-1 Portland sandstone and Kimmeridge Limestone oil discoveries lie within onshore Weald Basin licences PEDL137 and PEDL246 covering an area of 55 square miles (143 km²) north of Gatwick Airport. As previously reported on 21 March 2016, HH-1 flow tested at a significant commercial aggregate stable dry oil rate of 1,688 barrels of oil per day ("bopd") from the Portland, Kimmeridge Limestone 3 ("KL3") and Kimmeridge Limestone 4 ("KL4") reservoir horizons.

2018 Horse Hill Flow Test Programme

Following a short period of civil works to upgrade site facilities, a 150-day production testing programme focused upon the Portland, KL3 and KL4 reservoirs will commence. As commercially viable initial flow rates were established by the 2016 flow tests, the 2018 testing programme's goal is to confirm that HH-1's reservoirs are each connected to a commercially viable oil volume, thus enabling a declaration of commerciality to be made.

The Portland, KL3 and KL4 flow tests, each planned for around 30-40 days duration, will consist of a sequence of stabilised steady state flow and shut in periods to establish the oil in place ("OIP") directly connected to the well. A short maximum flow-rate test will also be included for each reservoir. If time permits, a further short-term test of a deeper untested Kimmeridge reservoir may be undertaken.

Testing will commence with the Portland reservoir, which in the Company's opinion, given the 323 bopd stable pumped rate achieved in 2016 and the 32 million barrels most likely OIP calculated by Xodus in 2017, is a strong candidate for commercial viability. Subject to a successful test, a Portland commercial declaration is expected to be made by mid-2018. A Kimmeridge commerciality declaration would follow programme completion and analysis of reservoir engineering data.

2018 Horse Hill Drilling Programme

Subject to a successful testing outcome in the Kimmeridge and Portland, the HH-2 well is planned as a future Portland producer, with an expected spud towards the end of Summer 2018. Drilling plans include optionality to deepen HH-2 into the Kimmeridge to gather core and image log data, together with a possible northwards deviation to access the adjacent oil bearing Collendean Farm fault block's significant Portland OIP.

The HH-1z Kimmeridge sidetrack spud is now planned for 2019 following construction of a Kimmeridge reservoir model utilising HH-1 Kimmeridge production data, reservoir data from the Company's 100% owned Broadford Bridge-1 & 1z Kimmeridge discovery and any future HH-2 Kimmeridge core.

Production Planning Application

To achieve its goal of stable, long-term Horse Hill oil production by Spring 2019, HHDL now plans to submit a further production planning application to SCC in late Spring 2018. This application will seek consent to produce oil initially from HH-1 & 1z, and HH-2, together with further production wells in a second contingent drilling phase.

Horse Hill Eviction

On Saturday 2 December 2017, a 42-person team, including High Court bailiffs and the UK's pre-eminent specialist protester removal contractor, successfully removed around 20 activists who had illegally occupied part of the Horse Hill site since Thursday 30 November 2017. These activists intimidated, jostled and verbally abused HHDL's security staff and caused criminal damage during their illegal occupation.

An increased security presence will now remain on the site until completion of the 2018 programme.

The Company is rigorously pursuing all available legal means to seek recourse for this and any future events that prevent or obstruct its right to conduct its lawful business.

Stephen Sanderson, UKOG's Executive Chairman, commented:

"The 2018 Horse Hill programme is a key step towards delivering UKOG's goal of commercial production and significant cash flow by early 2019. The programme, geared to provide data to support a declaration of commerciality, will benefit greatly from the many significant Kimmeridge and operational learnings gained at our Broadford Bridge discovery.

Horse Hill remains a fundamental part of the Company's core portfolio and we therefore look forward to returning to the birthplace of the Kimmeridge Limestone oil play. "

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 Sinclair-Ford Tel: 020 7220 1666

Cenkos Securities PLC (Joint Broker)

Joe Nally / Leif Powis Tel: 0207 397 8919

Public Relations

Brian Alexander / David Bick Tel: 01483 900583/ 01483 243450

Glossary

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
discovery	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
extended flow test or production test	a flow test, or extended well test, designed to test the longer term production performance of a discovery with a view to declaring commercial viability and the establishment of permanent production.
flow test	a test period where hydrocarbons are flowed to surface through a test separator. Key measured parameters are oil and gas flow rates, downhole pressure and surface pressure. The overall objective is to identify the well's capacity to produce oil at a commercial flow rate and to recover oil in commercial quantities or volumes
limestone	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, being made of the remains of calcareous planktonic algae called coccoliths. The Kimmeridge Limestones are comprised of fine grained coccoliths, fine grained calcium carbonate mud, clay minerals, together with dark grey organic matter
oil in place (OIP)	the quantity of oil or petroleum that is estimated to exist originally in naturally occurring accumulations before any extraction or production
play	a set of known or postulated oil and or gas accumulations sharing similar geologic, geographic, and temporal properties, such as source rock, migration pathways, timing, trapping mechanism, and hydrocarbon type
sandstone	a clastic sedimentary rock whose grains are predominantly sand-sized. The term is commonly used to describe a consolidated and cemented rock made predominantly of quartz grains
sidetrack	re-entry of a well from the well's surface location with drilling equipment for deviating from the existing well bore to achieve production or well data from an alternative zone or bottom hole location

UKOG Licence Interests

The Company has interests in the following ten UK licences:

Asset	Licence	UKOG's Interest	Licence Holder	Operator	Area (km²)	Status
Avington ¹	PEDL070	5%	UKOG (GB) Limited	IGas Energy Plc	18.3	Field in stable production
Baxters Copse ²	PEDL233	50%	UKOG Weald Limited	IGas Energy Plc	89.6	Appraisal/development well planned; licence extended to 2018
Broadford Bridge ³	PEDL234	100%	Kimmeridge Oil & Gas Limited ⁴	Kimmeridge Oil & Gas Limited ⁴	300.0	BB-1 & 1z drilling completed, testing of multiple zones underway
Holmwood ³	PEDL143	40%	UKOG	Europa Oil & Gas (Holdings) plc	91.8	Holmwood-1 exploration well planned in 2018
Horndean ¹	PL211	10%	UKOG (GB) Limited	IGas Energy Plc	27.3	Field in stable production
Horse Hill ⁵	PEDL137	32.435%	Horse Hill Developments Ltd ^⁶	Horse Hill Developments Ltd ^⁶	99.3	Planning Permission & EA permit granted for production tests and two wells
Horse Hill ⁵	PEDL246	32.435%	Horse Hill Developments Ltd^⁶	Horse Hill Developments Ltd ^⁶	43.6	As above
Isle of Wight (Offshore) ³	P1916	100%	UKOG Solent Limited	UKOG Solent Limited	46.7	Reviewing M prospect viability and well plan
Isle of Wight (Onshore) ^{2, 3}	PEDL331	65%	UKOG	UKOG	200.0	Preparing Arreton-3 planning submission
Markwells Wood ²	PEDL126	100%	UKOG (GB) Limited	UKOG (GB) Limited	11.2	Submitted planning application for appraisal and field development

Notes:

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 Broadford Bridge-1 and 1z discovery well and the extension of the Godley Bridge Portland gas discovery.

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 49.9% 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.