Amadeus Basin

Mosman owns one granted Permit and one application in the Amadeus Basin in Central Australia.

The Amadeus Basin is considered one of the most prospective onshore areas in the Northern Territory of Australia for both conventional and unconventional oil and gas, and hosts the producing Mereenie, Palm Valley and Surprise fields.


The permit contains a significant anticline (named West Walker), of over 30km in length. The anticline itself hosts Ordovician through to Neoproterozoic stratigraphy open at various levels. The significance of the geology is its proximity to the nearby Mereenie oil and gas field, which produces from the Ordovician Pacoota Sandstone unit. 

Two wells have been drilled on the anticline, the first West Walker -1 tested the western end of the feature based on a poorly definied seismic grid in 1982, but flowed wet gas to surface at a rate of 3.5MMscf/d from the Pacoota Sandstone, the main producing reservoir in the Mereenie Field. A follow up well drilled, called Tent Hill -1 (1984), located to the southeast on the same anticline (and very poor seismic grid was deemed unsuccessful, although oil was observed weeping from cores.

SRK Consulting (Australia) finalised a report ("SRK Report") into the prospective resources contained in permit EP 145 which is on trend with the existing producing Mereenie oil and gas field.  The report highlights the potential for both conventional oil and gas resources in proven reservoirs within the West Walker Anticline and unconventional gas resources in the Horn Valley Siltstone.

SRK has calculated unrisked prospective resources within both plays which are documented below:

Resource Type                                   P50

Conventional Recoverable Gas (Bcf)                12.44

Unconventional Recoverable Gas (Bcf)             1456

Table 1: Unrisked Resources (Source: SRK Report)

Placing to fund EP145 exploration

Mosman had considered joint venture partnerships to develop EP-145, however, on further review the Board believes it is an exciting opportunity and would be beneficial to retain its 100% ownership. Mosman completed a £1.5m Placing and now plans further exploration on this project in the Amadeus Basin where drilling results in nearby permits have demonstrated the commercial production of hydrocarbons and the presence of significant amounts of helium (up to 6% in Magee-1) and hydrogen.

The Placing will fund all the following work planned for 2021. It does not include drilling wells.

  • Airborne gravity survey in June 2021 to provide more detail regarding the deep geology in the permit, in particular the presence and distribution of salt deposits that provide the seal for helium, hydrogen and hydrocarbons.
  • The processing and interpretation of gravity data and updating the geological model.
  • The acquisition of seismic is aimed at defining a drilling prospect.
  • Followed by interpretation of seismic data.
  • Planning and long lead items for drilling.

In May 2021 the permit life and the minimum work requirements were again extended for 12 months which means that the gravity and seismic is required by August 2022.

In July 2021 the Airborne Gravity and Gradiometry data acquisition for permit EP-145 was commpleted. The survey is a significant step in the exploration program as it is the first time data will be acquired for the whole permit.  The survey used high resolution Falcon Airborne Gravity Gradiometry System which has the abililty to image salt and subsalt geometry across a range of depths.
Mosman has now contracted Geognostics Australia to interpret the data which will be integrated into the regional basin model.  It is estimated that this work will be completed late in the September quarter.
Planning for the acquisition of seismic is ongoing, and the plan cannot be ultimately finalised until the gravity is complete.

The Aboriginal Areas Protection Authority (APAA) sacred site clearance certificate has been received.  The Central Land Council (CLC) is currently working on their requirements for a heritage survey and also the requirement for an on-ground environmental survey.

The next step for Mosman will be to progress the technical work to further define the prospectivity of the permit. Acquisition and interpretation of 2D seismic will comprise the next significant exploration activity in the current permit year (expiring August 2022), prior to identifying a drilling location and drilling an exploration well (by August 2023). It is a requirement that prior to any field projects, including the 2D seismic noted above, a Sacred Site Clearance Survey (“Survey”) is acquired by the Central Land Council (CLC). This was agreed and scheduled by Mosman and the CLC for November 2021. Unfortunately, Mosman has been advised by the CLC very recently that the Survey will not now happen until April 2022. All seismic and drilling activities are subject to obtaining the necessary planning approvals from the NT Department of Industry and Resources, which are currently being coordinated by the project manager (ResourceGeo). In anticipation of any further delays to project approval Mosman may seek an extension and suspension to the current permit year.

EP(A)155 Mount Winter

Located within the prime Horn Valley Siltstone fairway between the Mereenie and Surprise Oil Fields, EP(A)155 contains the historical wells Mount Winter 1 and 1A that reported oil shows1. Seismic and well data comprise limited 2D seismic lines and two wells, one with oil shows. These oils shows were recorded within two formations:

  • The first trap with oil shows was in the Stairway Sandstone. The Stairway is the production layer (reservoir) at Surprise 1REH1. These tight conventional formations with good porosity but low permeability can flow-to-surface with new technology, and in particular multi-staged stimulation and horizontal drilling; and

  • A second trap was discovered in the Bitter Springs Formation determined to be of the Johnny Creek Beds petroleum bearing unit.  Oil shows here again were not flowed to surface as the technology to do so did not exist. There are also deeper formations which were not tested such as the Pacoota and deeper plays.

EP(A)155 is an exploration permit application; as such it is subject to successful land access negotiation with the Traditional Owners prior to the grant of the permit.

In May 2020 Mosman entered into a Farmout Agreement with Westmarket Oil & Gas Pty Ltd, a wholly owned subsidiary of unlisted public company Georgina Energy Plc, a helium focused business. Westmarket will be responsible for Native Title negotiations required for the permit to be granted.

Westmarket will also undertake technical work in accordance with the permit work programme, and thereby earn a 70% working interest and become operator of the permit. Mosman will retain a 30% working interest in the permit. At the time of drilling of a well, Westmarket may elect to carry Mosman through the cost of the well and in that case would earn a further 15% working interest, in this scenario Mosman would retain a 15% working interest in the permit.

Gas Pipeline

The Northern Gas Pipeline connects gasfields in the Northern Territory with gas markets in eastern Australia.  The pipeline runs between Tennant Creek in the Northern Territory and Mount Isa in northwest Queensland. The pipeline commenced operations in January 2019 and access is available to all shippers on commercial terms designed to incentivise the future development of Northern Territory gas resources.

The potential Amadeus to Moomba Pipeline shows further indication of increasing resources and development of the Amadeus Basin. This pipeline could provide access to the gas markets of South Australia, Victoria and NSW. The pipeline may also facilitate helium export from the Amadeus Basin.  CLICK HERE for further information.