Under a new strategic focus, three licence areas covering three Early Permian buried coal deposits located at Wintinna, Westfield and Murloocoppie in the northern part of the Arckaringa Basin, ~120 km north of Coober Pedy, have been evaluated both for possible open cut mining and for possible development of a value-adding coal-to-liquids conversion plant and a cogeneration power facility, by the conduct of in-depth feasibility studies. From 1980 until their surrender in 2004, a number of prior exploration tenements covering the coal deposits had been held by Meekatharra Minerals Pty Limited [see Envs 5910 and 8402], which changed its name to AuIron Energy and then to Felix Resources during this period. Norman Kennedy of Rank Geological Services Ltd took over management the tenements on behalf of Arckaringa Energy Pty Ltd, and subsequently transferred management of them in November 2005 to Arckaringa Energy's Australian based, but LSE - listed parent company Altona Energy Plc. During 2006, the licensee reviewed all the available historical data on the largest, Wintinna coal deposit, and commissioned several preliminary studies covering integrated CTL and power plant technology and design options, the updating of mine cost parameters, plus electricity and fuels market studies. After evaluating the results of these preliminary studies, the company commissioned Hatch Engineering (pursuant to its role as due diligence consultant to the Royal Bank of Scotland, Altona Energy’s project finance advisor) to conduct a “gap analysis”. This study evaluated the status of available information and advised Altona Energy as to the further work required to complete project evaluation to prefeasibility level and to establish a firm basis for commencing a Final Feasibility Study (FFS). Hatch’s report was issued to Altona Energy in April 2007, and the company immediately began acting on its principal recommendations. During the third year of the subject project, Arckaringa Energy performed exploratory drilling at the Wintinna deposit over the period May 2007 to February 2008, when 27 holes were drilled for a total penetration of 5561 m. Drilling targets were both Arckaringa Basin sediments (the Isolation seam to Waddikee seam interval of the upper Mount Toondina Formation) and overlying Eromanga Basin sediments (Bulldog Shale, Cadna-owie Formation and Algebuckina Sandstone). The objectives were to: a) obtain a representative bulk sample of approximately 5 tonnes of coal to use for processing tests such as washability and to evaluate other properties which will affect beneficiation; b) validate the previous exploration drillhole results that had been obtained in the vicinity of Arckaringa Homestead, and upgrade the defined JORC standard mineral resource to allow for the definition of at least 700 Mt of coal that could be classified according to then current JORC standards; c) address several data input gaps found in the previous hydrogeological investigation works which were undertaken in the area during the early 1980s; and d) conduct a mine planning geotechnical assessment of the deposit area to obtain an understanding of the earth material physical conditions that would affect the proposed open-pit mine, the granularity of this information including the characteristics of sub-units within each main geological unit. During the 2008-2009 project year, the licensee completed mining prefeasibility studies for the Wintinna deposit, which included a calculation of a revised JORC compliant total coal resource: Measured 187.08 Mt, Indicated 650.95 Mt, Inferred 480.78 Mt. These figures were based on geological data from a total of 142 drillholes, 27 of which lie outside the 50 square km resource model area that was centred near Arckaringa Homestead. The 838 Mt assigned to the Measured and Indicated resource categories covers only about 25% of the area of the deposit. Industrial engineering considerations, coal quality assessment results, evaluation of geotechnical data and hydrogeological modelling outcomes all indicated that the licensee could have confidence in proceeding to a bankable feasibility study. The key findings of the work are summarised on pgs 7-13 of Altona Energy's report issued to its stakeholders in August 2008. During 2009-2010, Altona Energy commissioned a detailed review of all existing coal quality data derived from current and previous analyses performed on samples of the Wintinna deposit, firstly to determine if the data from the different exploration programs is consistent and that the datasets can be safely merged, and also to assess the variability in quality characteristics, particularly those that might impact on the operation of a coal gasification plant. It was concluded from the review that there is significant inconsistency for total moisture and relative density between the old and new data, while there are also less variable but telling differences between sulphur, ash fusibility and ash analysis values, where the latter uncertainties would have important ramifications in coal gasification processes. During 2010-2011, after China National Offshore Oil Corp., New Energy International (Australia) Pty Ltd became a majority partner in the project, that company with approval from Arckaringa Energy retained the China National Administration of Coal Geology (CNACG) General Prospecting Institute to prepare technical review reports of the results from all previous coal exploration undertaken on EL 4512 and precursor licences. The reports were written in Mandarin and compiled to Chinese reporting standards. To comply with SA licence reporting requirements, Arckaringa Energy had the reports translated into English and provided them to PIRSA in electronic document format, as attachments to the 2011 joint annual report. A technical team from CNACG visited South Australia during January 2011 to hold a series of data review sessions with the licensee and its previous technical consultants, besides visiting exploration sites and the transport connections of the surrounding region. During the 2011-2012 project year, activity consisted of planning and preparing for doing future drilling and hydrogeological tests on EL 4512 to support the bankable feasibility study being funded and operated by CNOOC-NEI. The work programme was designed by CNACG, and subsequently it was reviewed and optimised by consultants GHD. It aimed to drill up to 34 boreholes for 7400 m, several of which would be multi-purpose. The key objectives of the programme were to extract bulk samples of coal to test and extend the coal quality profile, to complete an infill spread of coal sampling and coal geotechnical boreholes to facilitate open cut mine design (especially in an area covering the potential initial box cut), and to provide additional groundwater test wells to enable the refinement of the existing hydrogeological model. During 2012-2013, all of the necessary government regulatory approvals and work area clearances were obtained for undertaking the proposed work at Wintinna. It was scheduled to begin late in 2013 with the drilling of seven Stage 1 holes for 1678 m. The JV partners commissioned a feasibility study from Jacobs UK Ltd on the conversion of coal from the Wintinna deposit into liquid transport fuels and methanol by using existing robust and proven commercial technologies, in a plant with a capacity of 30,000 barrels per day of diesel and 6200 tonnes per day of methanol. The final report of this study was presented in June 2013. It concluded that the idea was feasible and could be run on a simplified flowsheet, with significant capital cost benefits, if the coal-to-methanol plant design was revised to give better process integration, and excess output tail gas, power and water were used within the plant to reduce overheads and generate more methanol. In this event the CTM plant would utilise ~95% of the CTL plant power export, while recycling of purge gas from the methanol synthesis loop could increase the CTL plant capacity by ~ 5%. A total construction cost estimate of US$1.48 billion was suggested in order to achieve these outcomes. After CNOOC-NEI withdrew from the project at the beginning of 2014, no further progress was made with the planned drilling while Arckaringa Energy conducted a re-assessment of priorities, exploration strategies and time lines. It was decided to concentrate new data collection on resolving high risk uncertainties that were seen to be critical to managing the project business case, in particular complex aspects of the mine dewatering plan. No further work on the project occurred between mid-2014 and mid-2019, before a decision was made to allow tenure of the subject licences to lapse.