5 June 2023

Mosman Oil and Gas Limited

("Mosman" or the "Company")

EP 145 Government Grant for Hydrogen and Helium Soil Sampling

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development, and production company, is pleased to announce that its application to the Northern Territory Government Geophysics and Drilling Collaborations (GDC) program has been successful. Mosman's subsidiary, Trident Energy Pty Ltd ("Trident"), has been awarded a grant of 50% of costs capped at AU$50,000 for the innovative targeting of hydrogen and helium using soil sampling to advance exploration activity.

The announcement was made by the Minister for Mining and Industry through the Northern Territory Government Newsroom. (https://resourcingtheterritory.nt.gov.au/gdc/current-round-successful-projects) The program is administered by the Northern Territory Geological Survey (NTGS).

The application is based on work proposed by Mosman's consultant geologist, Dr Julie Daws. The objective is to determine if hydrogen and/or helium can be detected at surface and how that relates to geological features such as faults or outcrops of porous formations. The work is expected to take place later in 2023. The results may assist in understanding the movement of helium and hydrogen and facilitate the optimal location of future drilling.

Mosman's Chairman, Mr. John W Barr, said: "I am extremely pleased with the technical endorsement and financial support of the Northern Territory Government for our continued exploration."

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

www.mosmanoilandgas.com