Extra-Deep Measurements Aid the Navigation of a Horizontal Well Through a Multi-Channel Turbidite Sequence

Summary Drilling high angle or horizontal wells through complex channel systems is a challenging issue that many operators face in field development. There are several areas where uncertainty in the planning stages cannot be overcome by conventional means such as drilling pilot holes, relying on seismic models and using log data from offset wells. An operator on the UK continental Shelf employed the use of extra-deep azimuthal resistivity to mitigate the planning uncertainties and successfully drill through a series of turbidite channels without the use of a pilot hole. Extra-deep azimuthal resistivity increased the probability of drilling a successful well in an area with seismic uncertainty and a lack of offset well data. This paper will describe how the use of extra-deep azimuthal resistivity, from the pre-well planning stage, through the drilling phase and post well analysis enabled the successful drilling of such a well where net sand drilled exceeded expectation, costs were reduced and an enhanced understanding of the reservoir geology resulted.