1.2.3.2.3 Coal seam gas exploration

Exploration targets in the Maranoa-Balonne-Condamine subregion are primarily the seams of the Walloon Coal Measures of the Surat Basin, though the Bandanna Formation of the Bowen Basin has been targeted in the north-western tip of the subregion. However, the coals were not found to have potential for CSG recovery (Blue Energy, 2010). Exploration in the most eastern part of the subregion, where the Surat Basin borders on the western edge of the Clarence-Moreton Basin, has indicated that here the Walloon Coal Measures are very shallow, with low gas content as a result of the proximity to the basin margin (Blue Energy, 2010). The coal seams of the Clarence-Moreton Basin have not presented a target for CSG exploration in the subregion to date (as of August 2014).

In addition to the ongoing exploration carried out by the four large CSG companies to ensure supply for the LNG projects, a number of smaller companies are currently exploring for CSG in the Maranoa-Balonne-Condamine subregion. The locations of three advanced exploration ventures are in Figure 17 and described in more detail below.

Figure 17 Petroleum tenures with coal seam gas exploration in the Maranoa-Balonne-Condamine subregion

Source data: DNRM (2014a), viewed 21 August 2014

ATP 626 (Icon Energy Limited)

Icon Energy Limited holds a 100% interest in ATP 626, which covers 758 km² north of Goondiwindi in the Surat Basin (GPInfo, 2014, viewed 15 July). Its position within the Maranoa-Balonne-Condamine subregion is indicated in Figure 17.

Icon Energy’s 2009 to 2011 exploration programme in the now relinquished Lydia block to the east of ATP 626 (see Figure 18) indicated low coal permeability and was consequently abandoned (Icon Energy, 2011). Two further exploration wells were drilled by Icon Energy in 2012 in the north-east of ATP 626 (see Figure 18): Eolus-1 and Windom-1. Though results of Eolus-1 were reported to be encouraging (Icon Energy, 2012), Icon Energy has since announced that the CSG play in ATP 626 proved to be uncommercial and has lodged a Later Work Program for ATP 626 to conduct conventional exploration (as of August 2014) (Icon Energy, 2014).

Figure 18 Exploration wells in ATP 626 in the Maranoa-Balonne-Condamine subregion. The Lydia wells indicate the now relinquished Lydia block

Source data: DNRM (2014a), viewed 21 August 2014

ATP = authority to prospect

Don Juan (Senex Energy Limited)

Senex Energy Limited (Senex Energy) is operator and shareholder of petroleum tenures ATP 593 and ATP 771, also known as Don Juan. The individual tenures are presented in Figure 19. The location of the tenures within the Maranoa-Balonne-Condamine subregion is shown in Figure 17.

The 2P reserves of the Don Juan tenure ATP 593 were given as 74 PJ as of December 2013 (DNRM, 2014d). Three exploration and one appraisal well (Kato 1 to 4, see Figure 19) had been drilled by Senex Energy by the end of 2013. Exploration results indicated good coal thickness and excellent permeability (Senex Energy, 2012). The 2P reserves at ATP 771 were quoted as 150 PJ (DNRM, 2014d). Three exploration and one appraisal well (Indy 1 to 4, see Figure 19) had been drilled by Senex Energy by the end of 2013. Results of the exploration were consistent with those from the Kato wells (Senex Energy, 2013a).

Figure 19 Exploration wells in ATP 593 and ATP 771 (Don Juan) in the Maranoa-Balonne-Condamine subregion

Source data: DNRM (2014a), viewed 21 August 2014

ATP = authority to prospect

ATP 854 (Blue Energy Limited)

ATP 854 is located near Injune, Queensland, on the central-northern border of the Maranoa-Balonne-Condamine subregion. While the tenure is located almost completely outside the Maranoa-Balonne-Condamine subregion, it is still included here as its most southern part borders onto the subregion, as demonstrated in Figure 17. ATP 854 is held and operated by Blue Energy and comprises an area of 800 km². Target coals in ATP 854 are those of the Permian Bandanna Formation of the Bowen Basin and the Jurassic Walloon Coal Measures of the Surat Basin (Blue Energy, 2010).

The Itude block of ATP 854 in Figure 20 is in close proximity to the depositional edge of the Surat Basin, indicating shallow coal seams with low gas content and low net coal thickness (Blue Energy, 2011). This was confirmed by the exploration programme (exploration wells Itude 1 to 3, see Figure 20) targeting the Walloon Coal Measures in this block (Blue Energy, 2010).

Exploration of the Bandanna Formation coals in the Bowen Basin in 2008 exhibited more promise. The core data from wells Cerulean 1 and Cobalt 1 (see Figure 20) indicated gas saturated coals with gas content of 8 to 13 m³/tonne (dry, ash-free basis) (Blue Energy, 2010). However, reservoir permeability was found to be low in pilot well Cerulean 2 (see Figure 20). Blue Energy is considering drilling a lateral well to intersect these coals (Blue Energy, 2010).

Figure 20 Exploration wells in ATP 854 on the border of the Maranoa-Balonne-Condamine subregion

Source data: DNRM (2014a), viewed 21 August 2014

ATP = authority to prospect

Other exploration activity

A list of CSG petroleum tenures located within the Maranoa-Balonne-Condamine subregion but not currently part of the projects described above is in Table 15. Information on CSG activity in the tenures is also provided as well as exploration plans where available.

Table 15 Coal seam gas petroleum tenures fully or partially in the Maranoa-Balonne-Condamine subregion

Source data: GPInfo (2014), viewed 18 August 2014.

2P = proved plus probable reserves; ATP = authority to prospect; ATPA = authority to prospect application; PCA = potential commercial area; PCAA = potential commercial area application; PEL = petroleum exploration licence; PELA= petroleum exploration licence application

The 2P reserves are as of December 2013 (DNRM, 2014d). NA means ‘data not available’