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Abstract Due to the punitive cost of drilling deepwater wells with 5th/ 6th generation rig rates flirting around $500,000/day, the need arose within the BP Angola Business Unit to plan a combined appraisal / development well as the first well on Platina West; a field which exists on seismic but remains unconfirmed with a well. The plan for this combined 'well for all seasons'* would have to be based upon high quality seismic and offset information from recently drilled discovery wells on adjacent fields. The expectation was that a cross-discipline team of engineers and geoscientists could plan one well - without recourse to expensive updip / downdip geological sidetracks - to replace the two traditional and sequential appraisal and development well types. This paper describes the Platina-2 well design and planning process followed to appraise all options and select the best wellplan to meet all the objectives. Given the present high cost and the forecast cost increase of deepwater well operations, the Platina-2 well planning process provides a useful example for future deepwater drilling operations where the two traditional appraisal/development well types can be rolled together into one combined well and save a considerable amount of field development CAPEX. The Platina-2 well design and its Statement of Requirements (SoR) are now complete and frozen; pending further detailed definition and eventual spud when a slot becomes available in the rig schedule. Platina Overview The Platina field is located in the Western region of Block 18 approximately 200 km offshore, Northwest of Luanda the Angolan capital (see figure 1). The structure is a North-South trending, North plunging, antiform formed by salt emplacement. Subsequent graben collapse due to Pliocene-Miocene salt withdrawal has divided Platina into two geographical regions; Platina Main and Platina West (see figure 2). Platina-1 was the first well to be drilled in Block 18 by BP in 1999 and encountered 3 reservoir intervals (M55, O71 and O72) in what is now termed the Platina Main area. The Platina West field is forecast to cover three unconsolidated sandstone horizons which the Platina-2 well trajectory will be the first to penetrate. |
