Operations Update

27 June 2022

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Operations Update

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development and production Company, is pleased to provide the following operations update.

Production for the three months ending 31 March 2022 was 22,409 boe (Gross), 11,756 boe (Net attributable to Mosman). Final June quarter numbers will be announced in late July and in the interim Mosman advises the preliminary numbers for the two months ending 31 May 2022 are: 15,682 boe (Gross), 6,276 boe (net attributable to Mosman).

Mosman emphasises that these numbers are still preliminary as formal receipts from the purchases are not yet available for May. Boe is barrels of oil equivalent based on calorific value as opposed to dollar value.

In the period January to May 2022, preliminary production numbers show continued solid production. It is highlighted that both oil and gas prices have risen significantly over the quarter and as Mosman continues to remain unhedged it will receive the benefit of current market prices.

Mosman also advises that:

-  In May production stopped at the Falcon well. An initial workover was attempted but was not successful. Planning is now underway to attempt to restore production.

-  A workover was completed at Stanley-5 in late May 2022. In the 20 days to 20 June 2022 a total of circa 2,300 barrels of oil were sold which represents a positive increase over previous months.

-  Further workovers at Stanley are now planned in July, subject to rig availability, with the aim to further increase production.

-  Drilling approval for the next drill has now been received from the authorities and preparation to drill Cinnabar-1 continues. Drilling is still on track and is scheduled to start in August-September 2022.

The Company is in the process of updating its corporate presentation ahead of its planned program of investor presentations in the coming weeks and will upload it to its corporate website.

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

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 seven 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.