11 October 2021

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Spud of Winters-2 Well

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development, and production company, announces the spud of the Winters-2 well in Polk County, Texas.

The Winter-2 well is now drilled to 1,445 feet with surface casing cemented. The intention is to drill to target depth in the next week. Casing has been purchased in preparation to complete the well. Any production flow rates will be announced when they are available.

Nadsoilco LLC, ("Nadsoilco") holds a c29% interest and is the Operator of the Winters lease. Nadsoilco is a 100% owned subsidiary of Mosman.

Nadsoilco is Operator of this well and has an effective c.23% working interest in this well.

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