ReconAfrica has reported a successful flow of natural gas and “potential liquids” to surface from two separate zones in the Kavango West 1X (KW1X) discovery well in the onshore Kavango Basin in northeast Namibia.
The upper Huttenberg zone flowed natural gas and potential liquids to the surface,ace, similar to the Upper Elandshoek zone, which also flowed hydrocarbons to the surfaceface earlier.
ReconAfrica has now completed vertical production testing at KW1X. The company has prioritized the Huttenberg formation for an open-hole horizontal production test, targeting up to 1,000 meters of horizontal section.
The uppermost zone of the Huttenberg formation flowed natural gas and potential liquids to surface immediately after perforation, before the company carried out any acid stimulation. The company flared the gas through the relief flare stack.
ReconAfrica did not measure flow rates from the Huttenberg zone because of equipment limitations. The company has now addressed the issue by purchasing the required equipment, which is currently being shipped to the site, and changing the surface operations service provider.
The company collected production samples containing natural gas and potential liquids in several IsoTubes. Laboratories in the United States will analyze the samples, with results expected in the coming weeks.
The test results mark the completion of vertical production testing at KW1X. ReconAfrica has stood down and demobilized the surface testing equipment used during the vertical programs it prepares for the open-hole horizontal production test.
After confirming natural gas and potential liquids flowed to surface from two separate zones at KW1X, ReconAfrica will now conduct an open-hole horizontal production test in the uppermost Huttenberg zone. The company also has the option to conduct another horizontal test in the uppermost Elandshoek zone.
ReconAfrica selected the Huttenberg formation for the first horizontal test because it:
- Flowed natural gas and potential liquids to surface.
- Contains 75 meters of pay based on the original well log analysis.
- Contains matrix porosity between large natural fractures.
- Provides a longer horizontal section because it sits about 600 meters shallower than the Elandshoek formation.
The Jarvie-1 rig is expected to drill up to 1,000 meters horizontally through the Huttenberg formation.
ReconAfrica President and CEO Brian Reinsborough said the company remains confident about moving ahead with the open-hole horizontal production test in the Huttenberg formation.
Reinsborough said the KW1X results confirm more than a single structure and create further exploration opportunities across the block. ReconAfrica has identified 22 structures using existing seismic data and expects that number to increase as it gathers more seismic data across PEL 73.
The company plans to confirm the KW1X results through a flow-rate test on a horizontal sidetrack as soon as possible. ReconAfrica expects the results to support future resource and reserve bookings and help inform a final investment decision for the Damara Fold Belt play.
ReconAfrica said it designed the vertical production testing program to determine which parts of the reservoir could flow hydrocarbons to the surface. The company did not design the program to establish flow rates because casing vertical wells does not provide the optimal development design for this fractured reservoir.
The first phase of production testing established that two of the six zones identified as areas of interest contain hydrocarbons that can flow to the surface.ace. However, the results do not rule out the possibility that the other zones could also flow hydrocarbons through a more suitable horizontal open-hole completion.
The company will now conduct an open-hole horizontal production test in the upper Huttenberg zone. The test will measure a representative flow rate across a larger exposed section of the reservoir without the restrictions created by production casing, cement,, and perforations.
ReconAfrica considers an open-hole horizontal well necessary to maximize reservoir penetration and intersect more natural fractures. The company designed the horizontal well to follow the natural fracture orientation observed in the reservoir.
ReconAfrica also expects horizontal development of the Damara Fold Belt structures to reduce surface land disturbance and the number of wells needed for each structure. The approach could also reduce field development costs and improve capital efficiency.
Formation imaging log (FMI) analysis from wells drilled through the Otavi reservoir shows fracture density ranging from 1.0 to 12.7 fractures per meter, based on the P90 to P10 range. The fractures run parallel to the fold structure.
The current well design includes a horizontal section of up to 1,000 meters to intersect these natural fracture zones more effectively.
ReconAfrica plans to complete the well as an open hole without casing or cement to maximize flow from the fractures.
The fractures have inclinations of 50 to 90 degrees, with most of them running vertically or close to vertically. The company will drill the horizontal well perpendicular to the fracture orientation.
Open fractures in similar carbonate fields can increase permeability and connect matrix porosity with the wider reservoir.
source: africaoilgasreport.com
African Energy Council