Premier Oil Plc. has completed the Sinapa-2, 2ST well offshore Guinea Bissau in West Africa. The well is being plugged and abandoned as an oil discovery.
Drilling began on Sinapa-2 on Feb. 15, 2004. The pre-drill objective was to drill vertically down the side of a salt column (diapir) and establish the presence of effective reservoir, hydrocarbon charge, and trap in sediments flanking the diapir. The exploration plan was to determine the precise depth of the Albian reservoir sequence and to drill a sidetrack well towards the salt diapir to evaluate the best trap location if the reservoir sequence was found. The Sinapa-2 well was drilled to a total depth of 3,657 m.
Pressure and structural data suggest that the oil column in the sidetrack well is in pressure communication with the oil column in the original well, defining a potential oil column in excess of 500 m within these steeply dipping beds flanking the salt diapir.
Though the Sinapa-2 well has gone some distance toward defining reserves in the Sinapa diapir prospect, reservoir quality and structuring issues will need to be thoroughly appraised and understood before any declaration of commerciality can be made. Premier is beginning to evaluate the data from the new well and anticipates a future program that will include new 3D seismic acquisition followed by exploration and appraisal drilling.
The results of this well have significantly reduced the risks of the salt diapir flank play in Guinea Bissau. Premier's acreage in blocks 2, 4a, and 5a includes a number of similar diapir structures that have the same play elements controlling hydrocarbon occurrence.
According to Charles Jamieson, chief executive of Premier, "The results of the Sinapa-2 well are encouraging for further exploration of our extensive acreage in Guinea Bissau now that the potential of the salt diapir play has been clearly proven."
Premier operates the block and holds 60% interest in blocks 2, 4A, and 5A (Sinapa and Esperanca blocks).