19 November 2020
- Drilling of the first exploratory borehole on Francis Plain Ring Road commenced on 2 November
- Several problems were encountered, including the drill string becoming jammed
- Works have been temporarily suspended until additional equipment is procured to continue with the project
Following the successful completion of the functional test to assess the performance of the 310WW Trailer Drill Rig, drilling contractor, Henry’s Contractors, commenced drilling of the first exploratory borehole on Francis Plain Ring Road, as part of the Exploratory Boreholes and Groundwater Drilling Project, on 2 November 2020.
The contractor drilled the first borehole to a depth of approximately 50 metres out of the target depth of 70-80 metres. Several problems were encountered during the works, which included difficult ground conditions and frequent hydraulic system breakdowns of the Drill Rig. At a depth of 50 metres, the drill string (the down-the-hole hammer and drill rods) became jammed.
Based on the documented testimonials of previous drillers, this is not an unusual occurrence, with drilling boreholes on St Helena presenting many challenges.
The drill string remains jammed, despite the contractor spending several days attempting various innovative recovery techniques.
As a result of this, the decision was made to temporarily suspend the works pending procurement of additional equipment, including drill rods, from South Africa. It is hoped that this equipment will arrive on the MV Helena in January 2021. Once the equipment has been received, the Drill Rig will be made ready to commence drilling of the second exploratory borehole.
The Programme Management Unit (PMU) would like to thank Henry’s Contractors for their sterling efforts to date, and for all involved with trying to free the drill string.
The public will be updated once additional equipment has been received and the Drill Rig has been prepared for the recommencement of drilling operations.
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SHG
19 November 2020