The south-western flank of the Bowen Basin hosts several small to medium sized gas/condensate fields with late Permian Tinowon and Muggleton Formation sandstone reservoirs. Recent exploration has highlighted the potential for larger gas/condensate discoveries in mildly over pressured tight sandstones and stratigraphic traps deeper on the western flank of the Taroom Trough. We present a model of a continuous Tinowon and Muggleton Formation (including the Lorelle Sandstone Member) play fairway on the western flank of the Taroom Trough. This fairway can be divided into three play segments, including (1) conventional structural, (2) structural/stratigraphic, and (3) tight gas/condensate sandstones with over pressured/stratigraphic traps. Tinowon and Muggleton Formation reservoirs were deposited in a complex mosaic of cold climate fluvial, flood plain, coastal plain, braided-fan delta, barrier/shoreface, and nearshore marine environments. Fluvial and coastal plains contain extensive peats. Sediments were primarily sourced from valleys draining western cratonic uplands composed of granite, low grade metasediments and siliceous volcanics, tuffs and andesite. Better quality reservoirs were sourced from the quartz rich Carboniferous Roma Granite. The extensive fluvial flood plain and coastal plain peats of the Wallabella Coal Member act as both a source and seal. Little exploration potential remains in the volumetrically smaller conventional structural traps in the shallower part of the play fairway. Greater potential exists in the deeper mildly over pressured play segment. The juxtaposition of source, reservoir, seal, and rapid vertical and lateral facies changes in this zone provides for stratigraphic trapping of reservoir sandstones. Thicker sandstone reservoirs and stratigraphic trapping within coals in the optimum over pressure zone offer the greatest potential for large volumes of gas/condensate. Future exploration will require densely spaced 3D seismic to map stratigraphic traps and differentiate between rapid vertical and lateral facies changes. Appropriate permeability enhancement through fracture stimulation/horizontal techniques will need to be cost effective and able to recover sufficient volumes of gas/condensate.

Open-Access Online Publication: May 29, 2023