into its top surface around each of the bowl profiles 24 26 in accordance with the present invention an offset casing hanger 30 suspending a string of oversize casing 32 is run through the well slot 24 and landed on the base plate 16 if desired or required an initial bore may drilled through the well slot 24 prior to running the oversize casing 32 the oversize casing 32 is connected to the offset casing hanger 30 via a conventional threaded connection 34 the offset casing hanger 30 is machined off center and is oriented in the bowl profile 24 using a conventional key and slot arrangement not shown thus as shown in fig2 the centerline of the casing hanger 30 is offset toward the centerline of the conductor pipe 14 the offset casing hanger 30 is preferably sealed to the bowl profile 24 with a suitable seal such as an elastomeric belt type packing 36 and is provided with a hole 38 which is adapted to accept any straight thread or pipe thread as may be necessary the offset casing hanger 30 and the oversize casing 32 serve to ensure that sufficient space exists to drill out the final well bore and run and set a final casing string through the well slot 24 after.