MGPalaeo has teamed up with Global Geopressure Advice (GGA) and Molyneux Advisors for a geopressure study of the onshore northern Perth Basin focusing on the Permian Gas Play, with particular attention given to the role of the Permian shales.
GGA’s geopressure study will integrate well data from MGPalaeo’s AUSTRALIS database for 99 wells with confirmed Permian penetration, plus data from Molyneux Advisors recent multi-client study, Integrated Reservoir-to-User View of the North Perth Basin. The focus of this study will be around the Waitsia, Beharra Springs, West Erregulla, and Lockyer Deep accumulations.
- Permian reservoir pressure interpretation to understand hydraulic connectivity between fields
- Identify and understand Permian shale overpressure
- Understand the evolution of overpressure and its linkage to tectonic activity and potential porosity preservation
- Construct models for overburden and fracture pressures to test seal capacity and critically stressed faults re leakage of fluids
- Determine, if possible, controls on column heights
Proposed Study Area
- Dandaragan Trough (part)
- Donkey Creek Terrace
- Beharra Springs Terrace
- Cadda Terrace (part)
- Dongara Terrace (part)
- Coomallo Terrace (part)
Regional map of the onshore northern Perth Basin, with the red bounding box showing the proposed outline of GGA and MGPalaeo’s new study.
On the 22nd September 2021 Norwest Energy published the results of the recent Lockyer Deep-1 gas discovery well.
- Petrophysical analysis of wireline data confirms exceptional reservoir quality in the Kingia Sandstone
- Net gas pay 20.2 metres (TVD) with average porosity 16% and average permeability estimated 500 millidarcies
- High reservoir pressures indicate an estimated 600-800 metre gas column
There have been other successful wells in the onshore Perth Basin, targeting the same play. However, there have been a series of wells that have encountered well control issues.
- West Erregulla-3 hit an overpressured zone (Carynginia shale; 0.7 psi/ft pressure gradient or 3360 psi overpressure) and West Erregulla-1 has evidence for connection gases suggestive of under-balanced drilling
- Tarantula-1ST1 was plugged back with cement following a well control incident from the primary target
A published interpretation (Ahmad et al. 2014) suggests that pore pressure in the Kockatea Shale varies significantly and that tectonic activity/uplift played a significant role via induced fractures, potentially explaining the elevated gas measurements in the shallower Lesueur Aquifer (Mullen et al. 2019). Furthermore, associated reservoir compartmentalisation may impact hydrocarbon resource estimates.
For more information on this study, please contact us.
Global Geopressure Advice, combine basin studies, sedimentology, structural geology, drilling and geomechanics to provide an integrated, holistic service to determine the influence of geopressure on risking prospects and safe well drilling.
Molyneux Advisors is a leading provider of subsurface advice to the energy industry. We do this through subsurface field development, reserves / resource assurance and by supporting products such as this geopressure study.