10 April 2025

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Vecta Helium Project Drilling Update

Mosman Oil and Gas Limited (AIM:MSMN) the helium, hydrogen and hydrocarbon exploration, development and production company, announces a drilling schedule update on the Vecta Project, Colorado, USA (20% WI).

Mosman previously announced that Vecta Oil and Gas Limited ("Vecta"), as the Operator, had signed a drilling rig contract with Desert Eagle Drilling LLC ("DED"), and several matters needed to be resolved before drilling would start.

Mosman's technical team met with Vecta in Denver on 7 April and discussed the geology and operational considerations of the planned five well drilling programme.

Vecta has now advised it is targeting mid-May to commence drilling the five exploration wells.

Andy Carroll, Chief Executive Officer of Mosman, said: "We look forward to Vecta drilling the five wells commencing in mid-May. Each of the prospects has been identified by Vecta based on years of experience and a thorough review of existing data, and each has its own individual characteristics. Mosman considers the key factors to be the helium concentration and the reservoir pressure that indicates the well production potential.

"One of the prospects is near the Model Dome field that was produced in the 1920s and had helium concentrations of 7-11%, and I am encouraged to see positive results at the Blue Star Helium/Helium One projects in the same area as the Vecta Project."

Mosman management and in-house technical team are attending the 2025 North American Helium & Hydrogen Conference in Denver this week and will take this opportunity to meet with other industry participants, have technical discussions with its partners and technical advisers, and conduct site visits.

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 a helium, hydrogen and hydrocarbon 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. The Company has several projects in the US, in addition to exploration projects in the Amadeus Basin in Central Australia.