Santos Offshore Pty Ltd, the Operator of the Winchester-1 exploration well being drilled in the Dampier Sub-basin permit WA-323-P, has announced that at 06:00 hours (WST) on Tuesday, 25 June 2013, the well was at a depth of 3803m MDRT (measured depth below rotary table), with the well static and the rig waiting on weather.
Over the last week, the well penetrated the target Triassic interval higher than predicted and a number of sandstone reservoirs were encountered with gas shows, the significance of which is being assessed. In a separate sandstone interval, below the intervals where the gas shows were recorded, an over-pressured zone was encountered with gas and water influx into the well. This necessitated the well being shut-in per standard oilfield practice.
Due to the current status of the well, the planned operations over the coming week are yet to be determined.
Winchester-1 is a deviated well that is being drilled by the Ensco-109 jack-up rig , in approximately 75m of water and to a planned total depth (TD) of 4803m MDRT. The well was originally scheduled to take approximately 80 days from the 7 April spud date to reach TD.
Winchester-1 is targeting the hydrocarbon potential of Triassic aged reservoirs mapped within a four-way dip closed anticline structural closure. The well has been designed, inter alia, to target at least four potential reservoir zones, each associated with high amplitude seismic events. Winchester-1 is located on the northeast trending Parker Terrace, representing a structural high separated from the Rankin Trend to the east.