ZIMBABWE: Mukuyu-2 drilling update: Elevated Gas Shows & Resistivity Encountered in Upper Angwa
Progress and current operations
Since the last update, the 9 ⅝” casing was set and the choke manifold for the blow out preventer (BOP) was changed out prior to commencement of drilling the 8½” hole section, which has reached the current depth of 2,745 metres Measured Depth (mMD).
Elevated mud gas peaks (up to 70 times above background gas baseline) have been observed while drilling to 2,582 mMD with marked increases from C1 to C5 compounds (methane, ethane, propane, butanes and pentanes). Elevated LWD resistivity and low Gamma Ray readings across this interval coincided with a drilling break and subsequent losses of drilling mud to the formation.
Drilling progress was slowed due to repairs to the top drive system, which have now been completed and remedying of mud losses to the formation.
Total background gas is higher than those observed in Mukuyu-1 and heavier hydrocarbons (C4 and C5) have been detected, providing further evidence of an active petroleum system in the basin.
Forward plan
Following the change out of the drill bit and batteries for the LWD tools, the Exalo 202 Rig will recommence drilling through the primary targets in the Upper Angwa (Alternations Member) and to the Lower Angwa (Massive Member) to approximately 3,750 metres MD before running a wireline logging evaluation suite.
Comments from Managing Director Scott Macmillan:
“We have encouraging signs in our Upper Angwa primary target, which has shown elevated gas readings including heavier hydrocarbons and elevated LWD resistivity across the zones of interest.
“The presence of elevated mud gas readings combined with elevated LWD resistivity and increasing background gas with depth is a positive sign as we progress through the Upper Angwa Alternations Member.
“Following a drill bit change, we are preparing to drill a further 1,000 metres to our planned total depth of 3,750 metres through the remaining Upper Angwa and into additional potential in the untested Lower Angwa.
“Once total depth is reached a comprehensive wireline logging programme to evaluate results will follow, with the aim of confirming the presence of moveable hydrocarbons in multiple zones.
“The well remains on track to be completed in the forecast 50 to 60 days.”