Horseshoe—Why we drilled our third target first
CGX drilled its third-ranked and stratigraphic target, Horseshoe West, June-July 2000 after the rig we'd contracted was forced off location at Eagle, our primary turbidite target. The rig was mobilized from Italy and arrived on the Eagle #1 location June 1.

At 12:15 am, June 3, Suriname Navy gunboats arrived at the Eagle location with no running lights and ordered the Rig and the Tidewater supply vessels to leave within 12 hours or face the consequences. For the safety of the crews and vessels, CGX immediately ordered a move to the Horseshoe West location, which was outside the zone Suriname was disputing. The rig was placed on standby. Several days of discussion between Guyana and Suriname produced no resolution of the conflict, so CGX began drilling at Horseshoe West.

The maritime border dispute between Guyana and Suriname was resolved under the United Nations Laws of the Sea. On September 20, 2007, the International Tribunal on the Law of the Sea (ITLOS) issued its ruling in favour of Guyana. For more details on the resolution, please visit Maritime Border Resolution.

Horseshoe Geology
The Horseshoe West target was a series of high-amplitude seismic events with modest AVO anomalies mapped over a large area of 30,000 to 60,000 acres. The nearest well controls were the Arapaima #1 well about 70 miles (118 km) NNW and the I23-1/X well about 55 miles (92 km) east, where the lower-most Maastichtian was a series of shales overlain by sandstones with minor carbonate and shales. The geological hypothesis was the presence of up to 3 sand packages on the flanks of the Berbice Canyon, which would be trapped by the shales overlying the upper Cretaceous unconformity surface seen in the Arapaima # 1 well.

We encountered essentially 100% extremely clean and porous sand from 5,705 ft (1,739 m) to 10,748 ft (3,276 m) covering a gross interval of 5,043 ft (1,537 m). The sand we encountered lies on the upper Cretaceous unconformity surface. The age of the sand package is bracketed from the lower Tertiary to the upper Cretaceous by the overlying and underlying beds. The overlying shales, observed at the Arapaima #1 and I23-1/X wells, didn't exist at Horseshoe West. The absence of a shale seal is the principal reason for the lack of success at this well and essentially eliminates any significant trap potential associated with the unconformity and the Berbice Canyon. These factors significantly downgrade our Horseshoe West, Horseshoe East and near-shore stratigraphic targets.

The massive sand thickness on the edge of the paleo-Berbice Canyon significantly upgrades our Eagle and Wishbone turbidite targets downdip.

Success in speed, safety and environmental protection
Drilling was accident-free, and there was no down time from planning shortfalls. The Crowley Marine Services barge did a good job of providing secure preparation of supplies, and marshalling arriving personnel and dispatching them to the rig in a timely manner by supply boat and helicopter. The drill program was successful in terms of speed, hole quality and cost effectiveness. This was largely a result of project supervision from Apex Energy Consultants and Cliff's Drilling Engineering Services and contractors from Trinidad, Guyana, and the U.S. CGX proved we could successfully complete remote international drilling on time and on budget.