Geology, Reserves and Resources
Regional Geology
The Bowen Basin extends from Central to Southern Queensland, Australia and covers an area of roughly 60,000 km². At its southern extent, the basin is overlain by the Mesozoic Surat Basin. The Bowen Basin is contemporaneous with the Gunnedah and Sydney Basins to the South (Esterle et al 2002).
The Late Permian deposits of the Blackwater Group are the primary CSG targets within the Bowen Basin. The Blackwater Group is divided into three terrestrial units – the Rangal Coal Measures (RCM), Fort Cooper Coal Measures (FCCM) and Moranbah Coal Measures (MCM). Figure 3 illustrates the chronostratigraphic relationship between the main units of the Bowen Basin.
Coal seams in the Bowen Basin exhibit major variations in rank and quality, reflecting both the depositional and tectonic history of the basin. A broad trend of increasing rank from west to east has long been recognised, and was used as a guide for coal exploration targets during the late 1950s and early 1960s (Queensland Department of Natural Resources and Mines 2003). Igneous intrusions present as dykes and sills are rarely found intruded through coal seams, causing coking and heat-affected coal which can potentially impact the economic potential of CSG.
The evolution of the Bowen Basin can be broken into four broad phases; a crustal extension phase, a thermal subsidence phase, a foreland loading phase and a basin closure phase (Fielding et al 1997).
MGP Geology
The MGP is located on the Collinsville Shelf in the north-west of the Bowen Basin. The Collinsville Shelf is an area that has undergone a period of major deposition and is characterised by low structural disturbance. Formations dip east at approximately 5° with small-scale and wide-spaced normal and reverse faulting showing small displacement.
To the east of the MGP lies the Burton Jellinbah fault Zone, a structurally disturbed area transecting the central and eastern region of the project area. This zone comprises a series of low-angle, large-displacement, NNW striking, east-over-west thrust faults totalling up to 800 m throw. Igneous intrusions present as dykes and sills are rarely found intruded through coal seams.
The Moranbah Coal Measures (MCM) are the primary CSG production targets over the MGP. The Goonyella Middle (GM), P and Q seams are common primary targets in the MCM. The Fort Cooper Coal Measures (FCCM) and its seams are secondary targets within the area.
JORC Reserves and Resources
The estimated proved and probable reserves, evaluated as of 31 March 2022 contained within PLs 191, 196, 223 and 224, referred to as the Moranbah Gas Project (“Moranbah Project”), located in the Bowen Basin of Queensland, Australia.
The volumes included in this estimate are attributable to coals in the LH seams from the Rangal Coal Measures and the GU, P, GM, and GL seams from the Moranbah Coal Measures. Economic analysis was performed only to assess economic viability and determine economic limits for the properties, using escalated price and cost parameters outlined in the Economic Parameters paragraphs.
Contingent resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations by the application of development project(s) not currently considered to be commercial owing to one or more contingencies. The contingent resources shown above are contingent upon acquisition of additional technical data that demonstrate producing rates and volumes sufficient to sustain economic viability of the project and, subsequently, the commitment to develop the resources. If these contingencies are successfully addressed, some portion of the contingent resources estimated may be reclassified as reserves; our estimates have not been risked to account for the possibility that the contingencies are not successfully addressed. The project maturity subclass for these contingent gas resources is development pending or development on hold.
The estimates of Reserves and Contingent Resources detailed above have been provided by Benjamin W. Johnson of Netherland, Sewell and Associates Inc (“NSAI”) in accordance with the Society of Petroleum Engineers’ Petroleum Resource Management System (SPE-PRMS) guidelines. Mr Johnson is a Licensed Professional Engineer in the State of Texas) and has consented to the use of the information presented herein.
The technical persons primarily responsible for preparing the estimates presented herein meet the requirements regarding qualifications, independence, objectivity, and confidentiality set forth in the SPE Standards.