Invictus Energy confirms working hydrocarbon system at Mukuyu-1 exploration well
Invictus Energy has encountered elevated gas shows and fluorescence in the Upper Angwa primary target of Mukuyu-1.
Independent upstream oil and gas company Invictus Energy (ASX: IVZ) has confirmed the presence of a working hydrocarbon system at its 80%-owned Mukuyu-1 well in Zimbabwe’s Cabora Bassa basin.
Elevated mud gas peaks of up to 65 times above the background gas baseline have been observed while drilling to 3070mMD (metres measured depth), alongside marked increases in C1 to C5 compounds (methane, ethane, propane, butanes and pentanes).
An initial 100% fluorescence was also observed in a downhole cuttings sample of sandstone, indicating the presence of condensate or light oil when placed under ultraviolet light.
Logging while drilling (LWD) analysis identified shallower zones of interest within the Upper Angwa primary target, with elevated mud gas readings and LWD resistivity observed.
Additional potential zones of interest in the Pebbly Arkose and Forest formations have also displayed elevated resistivity.
Drilling towards total depth has been slower than expected due to challenging conditions in the Pebbly Arkose, where several loss zones were encountered, requiring remedial action to stabilise drilling fluid losses.
Conditions subsequently improved in the Upper Angwa prior to the failure of the stator in the down hole drilling motor.
This required the changeout of the motor before drilling could continue through the formation towards a planned total depth of approximately 3,500mMD.
Buoyed by results
Invictus managing director Scott Macmillan said the company had been buoyed by results from Mukuyu-1 drilling.
“Early indications in the Upper Angwa target are highly encouraging and have proven a conventional working hydrocarbon system in the Cabora Bassa basin, which is an exciting development validating our subsurface model,” he said.
“The presence of elevated mud gas readings, fluorescence in the cuttings, elevated LWD resistivity and increasing background gas with depth is a positive sign as we progress through the Upper Angwa Alternations Member.”
Mr Macmillan said all zones of interest would be evaluated through a wireline logging program, which will commence once Mukuyu-1 reaches total depth.
The program will aim to confirm the presence of moveable hydrocarbons in multiple areas of the basin.
Untested frontier region
The Cabora Bassa Basin is one of the last untested large frontier rift regions in onshore Africa.
Invictus is conducting a high-impact exploration program through the region, focusing on the Mukuyu-1 well.
Mukuyu is the largest undrilled prospect in onshore Africa independently estimated to contain 20 trillion cubic feet and 845 million barrels of conventional gas condensate (on a gross mean unrisked basis).