Invictus Energy Limited has announced a gas discovery in the
Mukuyu-2 well at its 80% owned and operated Cabora Bassa Project in Zimbabwe.
Comments from Managing Director Scott Macmillan: “We are delighted to declare a gas discovery from the Mukuyu-2 sidetrack well in the Upper Angwa
formation.”
“The discovery represents one of the most significant developments in the onshore Southern Africa oil and gas industry for decades.”
“I’m extremely proud to be involved with the Invictus team and our partners in opening up one of the last untested rift basins. The perseverance and hard work by of our dedicated team has paid off.”
“The company has delivered an exceptional result from the first two wells drilled in Mukuyu, which provides us with significant running room in our large portfolio of prospects and leads for further discoveries in our acreage in the Cabora Bassa basin.”
“The Mukuyu-2 discovery, 7 km away and 450 m updip of the Mukuyu-1 well, which can subsequently be classified as a discovery, provides confirmation of the large potential of the Mukuyu field which has a structural closure of over 200 km2.
“With additional hydrocarbon bearing reservoirs ahead, the focus now is to complete the drilling and evaluation programme and obtain further wireline data including fluid samples to declare an additional discovery from the Lower Angwa formation.”
Progress and current operations
Whilst drilling towards the base of the Upper Angwa formation and following indications from real-time logging while drilling and mudgas data, intermediate total depth (TD) was called at 2987 m measured
depth (mMD) and the company elected to undertake an intermediate wireline logging run with the primary objective of obtaining hydrocarbon samples from Upper Angwa reservoirs.
A limited suite of wireline logging data was acquired over the interval from 1969 mMD to 2975 mMD in the Basal Pebbly Arkose and Upper Angwa formations which identified multiple hydrocarbon bearing
reservoirs in the Upper Angwa.
A total of four hydrocarbon samples were recovered to surface from two separate zones in the Upper Angwa using the wireline formation testing tool. A further two formation water samples were recovered
from the Basal Pebbly Arkose formation.
Gas and fluid properties from the recovered samples will be confirmed following laboratory testing once the sample bottles are dispatched from the rig for analysis.
No additional fluid samples were captured in order to preserve the wireline formation sampling tool and remaining sample chambers for use in the interpreted Lower Angwa hydrocarbon-bearing zones
where thicker sandstone units were penetrated in Mukuyu-2.
Wireline log interpretation calculates a preliminary net pay estimate of 13.9 m for the Upper Angwa, however, this estimate is still subject to further calibration of the logs with core and fluid data to determine appropriate net cutoffs and subsequent pay estimates. Significant additional gross sands were intersected within the Upper Angwa gas leg but are below the current net reservoir cutoff. These intervals may have better reservoir development elsewhere in the Mukuyu field and along with the refinement to the net pay criteria represents additional upside. Further appraisal and technical evaluation of log, core, seismic and well test data is required to determine the full extent of the resource size. The discovery also bodes well for other prospects and leads in the remainder of Invictus Energy’s large acreage position in the Cabora Bassa Basin. Following the fluid sampling, thirteen large volume sidewall core samples were recovered from priority points in the Pebbly Arkose and Upper Angwa which will be used to calibrate the wireline log data in post-well analysis.
The sidetrack well will now be deepened towards the planned TD, in the Lower Angwa, at around 3400 mMD. The ultimate TD will depend on the intersection of sands anticipated based on the Mukuyu2 logs and observations around the prevailing formation pore pressures. A technical summary and disclosure requirements are provided at the end of this report.
Forward plan
The Exalo Rig 202 will drill ahead towards the sidetrack section TD at approximately 3400 mMD through Lower Angwa reservoirs where multiple zones interpreted from logs to be hydrocarbon-bearing were intersected in Mukuyu-2. Following the conclusion of the drilling of the 8.5 in. hole section, the sidetrack well will be logged including wireline formation testing and fluid sampling and final results provided.
Completion of the sidetrack will also allow for the well to be suspended for future flow testing by running the 7 in. liner over this interval. This will provide the opportunity to drill, evaluate and test the remaining portion of the Lower Angwa, below 3400 mMD, in 6 in. hole in future operations. Overpressured gas bearing reservoirs were encountered in this interval in the original Mukuyu-2 wellbore.
Read the article online at: https://www.oilfieldtechnology.com/exploration/08122023/invictus-energy-limited-announces-gas-discovery-in-zimbabwe/