12 April 2022

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Winters-2 Increase in Production by 31%

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development, and production company, announces increased production from the Winters-2 well in East Texas. Mosman has a c.23% working interest in Winters-2.

The Winters-2 well has been connected to the recently completed gas infrastructure. Initial production was reported on 14 March 2022 and the choke was subsequently increased from 9/64" to 11/64" and the gross production flow rate in the period from 6 to 10 April averaged 902 thousand cubic feet per day (mcfpd) which is circa 1,012 mmbtu or 170 barrels of oil equivalent per day (boepd). In addition, 10 barrels of oil per day (bopd) were produced bringing the fiveday average gross production to 180 boepd. This represents an increase of c. 31% on the gross production rate as reported on 14 March 2022.

John W Barr, Chairman, said: "It is pleasing to this increase oil and gas production at Winters-2, especially with the Henry Hub gas price currently at USD 6.80 per mmbtu. Mosman's sales are based on the Henry Hub price less pipeline costs and taxes."

Market Abuse Regulation (MAR) Disclosure

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 ('MAR') which has been incorporated into UK law by the European Union (Withdrawal) Act 2018. Upon the publication of this announcement via Regulatory Information Service ('RIS'), this information is now considered to be in the public domain.

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www.mosmanoilandgas.com