Moray Firth/Witch Ground Graben
23 April 2018

Exploration well on Rothesay prospect, an amplitude/AVO play with strong Class II response within Lower Balmoral M4a Upper Sandstone unit in pinch-out trap requiring enveloping thin intra- formational shales to seal. Main hole junked. Re-spud encountered short dead oil zone within Oligocene Intra-Lark sandstone at 2,979–3,011 ft TVDSS (secondary target), but water-wet high net/gross Lower Balmoral from 6,511 ft TVDSS, including M4a Upper objective (6,891 ft TVDSS) with no shows. AVO response interpreted post-well as interference of thin carbonate stringers within M4a Upper Sandstone and overlying S3 Upper shale.