Nexen Discovery, Eastern Gulf of Mexico

Nexen and its partner have made a significant discovery in the Eastern Gulf of Mexico at Appomattox, located in Mississippi Canyon blocks 391 and 392. Recent operations at Appomattox have resulted in an oil discovery with excellent reservoir quality, following the drilling of an exploratory well and two appraisal sidetracks. Nexen has a 20% interest in Appomattox which Shell operates and holds an 80% interest. The discovery well, located in 7,217 feet of water, was drilled to a depth of 25,077 feet true vertical depth and encountered approximately 530 feet gross (425 feet net) true vertical thickness of oil pay. An appraisal sidetrack was drilled to approximately 25,950 feet true vertical depth and encountered approximately 380 feet (360 feet net) true vertical thickness of oil pay. The second sidetrack was undertaken to further delineate the discovery. Well results have exceeded our pre-drill expectations.

Appomattox is the third discovery in the area following early discoveries at Shiloh and Vicksburg. Additional appraisal activities are planned for later in the year and we are investigating development options for Appomattox and Vicksburg, located six miles east. We have a 25% interest in Vicksburg and a 20% interest in Appomattox and Shiloh. Shell Offshore Inc. operates all three discoveries.

"The Appomattox discovery confirms our confidence in the play and provides a strong basis to evaluate the remainder of our significant acreage position in the Eastern Gulf of Mexico," commented Marvin Romanow, Nexen's President and CEO. "We are looking forward to additional drilling at Appomattox to confirm the estimate of total resource and move the discoveries towards development."