14 March 2022

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Stanley-4 First Gas and Oil Production

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development, and production company, announces initial gas production from the Stanley-4 well in East Texas. Mosman has a 36.5% Working Interest.

The Stanley-4 well has been connected to the recently completed gas infrastructure. The initial gross flow rate is circa 275 thousand cubic feet per day (mcfpd), which is circa 53 barrels of oil equivalent per day (boepd). In addition, 6 barrels of oil (bopd) were produced bringing the initial daily production to 59 boepd. The well will be monitored, and production rate optimized.

The other well recently connected to the gas infrastructure is the Winters-2 well. Mosman has c23% working interest. Gross production rate from 7 to 11 March averaged 657 thousand cubic feet per day (mcfpd) which is circa 127 barrels of oil equivalent per day (boepd). In addition, 10 barrels of oil per day (bopd) were produced bringing the 5 day average production to 137 boepd.

John W Barr, Chairman, said: "It is pleasing to see Stanley-4 producing oil and gas and we are encouraged by the oil production data at Winters-2. Going forward, the gas infrastructure will be useful in optimizing production, for example by enabling gas lift on other Stanley oil wells."

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 inside is now considered to be in the public domain.

Enquiries:

Updates on the Company's activities are regularly posted on its website:

www.mosmanoilandgas.com