URL: https://geoscience.data.qld.gov.au/dataset/cr135197
The Paranui project area is in ATP769P in the southern Bowen Basin, 14 km south of the Township of Moura and west of the adjacent Meridian CSG-producing field. Conoco conducted a three-well pilot program in 1996. All Conoco wells were fracture stimulated and gas production commenced in 1997.
Paranui 5 was drilled in July 2007 (top hole) and February/March 2008 to 225 m and abandoned in May 2008 after unsuccessful attempts to fish a stuck drilling assembly. Paranui 5R was spudded 10 m to the south on 3-Jun-2008 by Ensign Energy Services Rig 20. The well was drilled to 1033 m and the rig was released on 16-Jun-2008.
A total of 13 seams including one fault repeated seam horizon were intersected in Paranui 5R. The coal seams ranged in thickness from 0.65 m to 3.40 m thick, for a total of 23.25 m of net coal in the Baralaba Coal Measures and Kaloola Member.
On 19-Jun-2008, BJ Services performed a three-stage fracture stimulation targeting the Baralaba coal measures. The well was then completed on 28-Aug-2008, and the well commenced dewatering and production testing.
In December 2010, high levels of Carbon Dioxide (CO2) (38.5 vol%) and Hydrogen Sulfide (H2S) (100 ppm v/v –or– 140mg/m3) were detected in gas samples taken from the well. While the origin of the H2S in the well was not definitively determined, the most likely scenario was that water pumped into the well during drilling or stimulation may have contained sulfate-reducing bacteria (SRBs).
For health and safety and well integrity reasons, WestSide chose to suspend Paranui 5R pending regional analysis and commenced planning for the plugging and abandonment of the well.
No other samples from WestSide-operated wells in the region (Paranui or Meridian Fields) detected H2S at similar levels in gas or water streams.
The well was plugged and abandoned in August 2012. Secure Well Services (SWS) was engaged to complete the P&A of the well between 13 to 23 August 2012.