Namibia drilling hits snags

May 21, 2014

Drilling on the deepwater Welwitschia-1 prospect in Walvis Bay, offshore Namibia, might be delayed until the end of May after the wellhead housing “slumped” and issues with the blow out preventer (BOP) control system were discovered.

Operator Repsol Exploration (Namibia) spudded the well on 24 April, but, says partner Tower Resources, following the installation of 36in. casing it was observed that the wellhead housing had slumped. The partners decided to plug and abandon the well and re-spud a new well, Welwitschia-1A, about 50m away. Welwitschia-1A was spudded on 1 May, but operator Repsol then reported a delay due to a fault with part of the blow out preventer (BOP) control system.

“Drilling has been suspended whilst Repsol and the drilling contractor, Rowan, are taking measures to rectify the fault so that they are able to recommence drilling safely,” a statement, issued via Tower Resources says. “It is estimated that commissioning issues relating to the BOP control system will delay further drilling until the end of May 2014.”

The Welwitschia-1 prospect is targeting net risked recoverable resources of 496MMboe to Tower's 30% interest, putting the total estimate at about 1.6billion boe. The well will intersect up to five separate reservoir targets ranging from the Palaeocene-Maastrichtian to the Albian Carbonate sequence at a potential total depth (TD) of 3000m (true vertical depth subsea). The operator expects this to take up to 46 days.

Operations in Namibia petroleum exploration license (PEL 0010), operated by Repsol, and containing Welwitschia, are using the Rowan Renaissance drillship (pictured). It will be the Rowan Renaissance’s first drilling program, after its delivery from Hyundai Heavy Industries (HHI) in Korea. Tower said mobilization was “a little later than expected owing to prolonged acceptance-testing by Repsol in advance of it taking the drillship on a three-year contract.”

The statement continued: “The current status of the well is that casing has been set to a depth of 1879m and we anticipate drilling into the primary target section shortly following the restart of drilling operations.”

Jeremy Asher, Tower Resources' chairman, commented: "It is not unusual to encounter technical issues with new equipment and in particular BOPs on-board a new drill-ship such as the Rowan Renaissance. However, safety is of paramount importance to Tower and its JV Partners and we are confident that Repsol and Rowan will resolve the BOP issues shortly and we look forward to informing the market when drilling recommences. These issues have no connection with the prospects for the well itself, which remain as exciting as ever.”