The 2018 sale and purchase agreements with APLNG stratified (or divided) the southern Denison Trough permits into a standalone shallow and deep project. This resulted in Denison Gas acquiring a 100% and Operator-ship of the shallow Southern Denison Trough project area and a 50% working interest of the Westgrove Deeps project.
The Westgrove Deeps project is a significant tight gas play targeting the lower Reids Dome Beds. Denison Gas’s current assessment of the risk adjusted recoverable gas resource is 491PJ. APLNG success case recoverable gas estimates are as follows:
- P90: 308PJ
- P50: 860PJ
- P10: 2032PJ
The focus of the joint venture will initially be on drilling the Westgrove 9 exploration/appraisal well scheduled for late 2018.
The Westgrove Deep play is situated in PL44 and underlies the Westgrove and Merrivale fields. The prospect was penetrated by the Westgrove 3 well drilled in 1963. This well flowed gas to the surface from sand stones at ~3,750m. The gas composition was 97% methane with ~3% inerts. The mud weight used to drill the reservoir section suggests high over pressures (up to ~1,060psi). This would indicate a significant gas column.
From gas readings encountered during drilling, a 200m gross gas column was penetrated and the column was thought to be only partially penetrated. Westgrove 3 was plugged and abandoned due to casing issues. The joint venture has approved an initial $50 million Westgrove Deeps work program. Following analysis of the data in the vertical hole, the Westgrove 9 well may be side-tracked horizontally to target sandstone layers with high potential.
PCA’s 153 and 154 are located 40 km north of the Springton gas plant and 10 km west of the regional town of Emerald. Both Santos and APLNG, had identified 64PJ of 2C CSG resources and had not completed a formal resource assessment of the Yamala conventional gas discovery. The two wells which intersected the Yamala discovery both flowed gas to the surface. In addition to these discoveries, there remains several opportunities for additional conventional and CSG targets as identified by the previous operator. These opportunities will continue to be explored by Denison Gas via its forward work commitments.