3 October 2022

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Spud of Cinnabar Well

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development, and production

company, announces that the Cinnabar-1 well in Tyler County, Texas commenced drilling (spudded) on 30 September 2022.

The Cinnabar well is planned for a vertical depth of 9,900 feet. The primary targets are the

Wilcox sands, which produce oil and gas in nearby wells. The drilling is expected to take about

two weeks.

Mosman owns a c.75% working interest in the well. Mosman Operating LLC, a 100% owned

subsidiary of Mosman, is the Operator of the lease.

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.

Enquiries:

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

www.mosmanoilandgas.com

Notes to editors

Mosman (AIM:MSMN) is an oil exploration, development, and production company with projects in the US and Australia. Mosman's strategic objectives remain consistent: to identify opportunities which will provide operating cash flow and have development upside, in conjunction with progressing exploration of existing exploration permits. The Company has several projects in the US: Stanley, Greater Stanley, Livingston, Winters, Challenger and Champion in East Texas and Arkoma in Oklahoma in addition to exploration projects in the Amadeus Basin in Central Australia.