ReconAfrica to explore new play in Kavango basin, Namibia
Reconnaissance Energy Africa Ltd. (ReconAfrica) has applied for drilling permits to explore a new play in the Damara Fold Belt in southern and western parts of exploration license PEL 73, Kavango basin, Namibia.
This new belt, initially identified southwest of Karoo Rift basin, consists of a prominent and clearly imaged series of Whaleback anticlines, which are often faulted, and have a consistent linear trend in a NW to SE direction.
With growing seismic data coverage used to identify these fold structures, 16 such structures have been recognized so far, with an areal extent of up to 50,000 acres (200 sq km) and about 650 ft (200 m) of column height, similar to structures found in the Zagros Fold Belt in Iran and Iraq, the company said in a release Apr. 3.
Earlier 2D seismic combined with stratigraphic test wells which penetrated the underlying Damara section (pre-Karoo aged stratigraphy), initially identified the fold belt below the Karoo Rift Basin and confirmed the trend and presence of these fold structures, carbonate reservoir rocks with up to 17% matrix porosity, fracture porosity, and significant oil shows.
Gas samples from the most recent stratigraphic test well, sampled in Isotubes during drilling this (pre Karoo) section, show thermogenic methane gas and good concentrations of hydrocarbon gas liquids. Importantly, a natural gas seep has been located on top of one of these elongated anticlines, the company said.
Stratigraphically, the Damara section (pre-Karoo) is expected to contain multiple source rock intervals associated with glacial and post-glacial anoxic events, continental, and marine organic rich source rocks. It is expected the reservoirs and seals would be composed of stacked sequences of sands, limestones, dolomites, and shales.
Extension of the Phase 2 seismic program, which is currently being acquired, was designed to increase the seismic control, validate and delineate the full extension of this new play type. The 2D seismic data will be supplemented by a recently permitted high resolution full tensor gravity (eFTG) survey. An integrated interpretation of seismic, well data, eFTG, and aero-magnetics has been prioritized and will enable three dimensional mapping of these large structures.
ReconAfrica has applied for drilling permits for six Damara locations, which are subject to further refinement once final data acquisition and interpretation are completed by July 2023.
Extension of the phase two seismic program was also designed to delineate the full extension to the southeast of Karoo Rift basin. Timing for additional Rift basin wells, including previously announced 5-1 well in Rift basin, is postponed until completion of seismic, eFTG, full sequence stratigraphic integrated interpretation, and prospect ranking for the entire license area.
Acquisition of the Phase 2 extension 2-D seismic program (about 1,500 km) is expected to be complete in May, finalizing planned regional seismic acquisition totaling about 2,800 km. This program expands coverage of the new Damara Fold belt province and over the initial Karoo Rift basin play to the southeast corner of PEL 73. Results of the next well to test one of the structures in the Damara Fold Belt will be a part of the area wide risk weighted ranking of multiple play types.
Simultaneously, with the accelerated exploration focus on the Damara Fold Belt, a petroleum system analysis will evaluate source rock maturity, generation, and expulsion timing of hydrocarbons. This will be augmented by seismic sequence stratigraphic interpretation and mapping of the depositional environments to provide management with a better understanding of the petroleum system, play fairway, and its variation within the entire Kavango stratigraphic basin.
Alex Procyk | Upstream Editor
Alex Procyk is Upstream Editor at Oil & Gas Journal. He has also served as a principal technical professional at Halliburton and as a completion engineer at ConocoPhillips. He holds a BS in chemistry (1987) from Kent State University and a PhD in chemistry (1992) from Carnegie Mellon University. He is a member of the Society of Petroleum Engineers (SPE).