Exploration & Production Success Continues off Atlantic Canada

Offshore Canada’s Atlantic coast has proven to be a very oil rich region. The first well drilled offshore was in 1943. The Island Development Company drilled the Hillsborough #1 well 13 km from Prince Edward Island in 8 m of water. The well reached 4,478 m. Two years later the well was dry and abandoned, and a series of non-commercial wells followed.
NOVA SCOTIA

Shell drilled the C-67 well off Nova Scotia in 1967. The major stopped drilling that well when it hit gas-bearing Cretaceous rocks with high pressures.

Shell and Mobil continued exploring on the Scotian shelf into the early 1980s. The majors experienced blowouts at two separate discovery wells. The Vinland semisubmersible drilled Shell’s Uniacke G-72, which took over a week to bring under control; whereas Mobil’s West Venture well took 8 months to shut in.

Nevertheless, Shell and Mobil continued to make discoveries in the region. Shell drilled the Onandaga E-84 well in 1969, and Mobil drilled the D-42 Cohasset well in 1973 and the Venture field in 1979.

Despite disappointments along the way, ExxonMobil and partners Shell, Esso, Pengrowth Energy Trust, and Mosbacher Operating Ltd. found success off Nova Scotia

Cohasset turned out to be the first commercial offshore Canadian discovery. Initially, Mobil thought the well was marginal, but in December 1985 Petro-Canada drilled the Cohasset A-52 step-out well, which was southwest of Mobil’s 1973 discovery well. Petro-Canada’s well tested oil at a combined rate of 38,918 b/d from six zones.

Shell got in on the action drilling a discovery well at Panuke, which was about 8 km southwest of Cohasset. Shortly after, Petro-Canada drilled a delineation well that tested oil at 69,188 b/d for six days. While both Cohasset and Panuke were marginal, together they were deemed commercial. The wells were produced from 1992 to 1999.

Despite disappointments along the way, ExxonMobil and partners Shell, Esso, Pengrowth Energy Trust, and Mosbacher Operating Ltd. found success off Nova Scotia. The Sable Offshore Project is the largest construction project ever undertaken in Nova Scotia. The project produces about 80 MMb/d and 20,000 b/d of gas.

The Sable Offshore Project is divided into two tiers of offshore development. The first tier was completed in December 1999 and involved the development of the Thebaud, North Triumph, and Venture fields, as well as the construction of three offshore platforms, an onshore gas plant, and an onshore fractionation plant. First gas was produced on Dec. 31, 1999. Alma, the first Tier II platform came onstream in 4Q 2003, while production from South Venture, the second Tier II field, began late in 2004.
NEWFOUNDLAND AND LABRADOR

First drilled in 1971, Labrador is known for its bitter cold temperatures and icebergs that make exploration and production in this area hazardous. Drilling ceased in this area in the early 1980s for more favorable conditions in the southern waters off Newfoundland.

Exploration began on the Grand Banks (Avalon and Jeanne d’Arc basins) in 1966 with no success. Ten years later, Hibernia was discovered. Today Hibernia is owned by ExxonMobil Canada (33.125%), Chevron Canada Resources (26.875%), Petro-Canada (20%), Canada Hibernia Holding Corporation (8.5%), Murphy Oil (6.5%), and StatoilHydro Canada Ltd. (5%).

The Hibernia field began producing on Nov. 17, 1997. The field is 315 km east of St. John’s in 80 m of water. It is the fifth largest field ever discovered in Canada. The field produces from two reservoirs of early Cretaceous age – the Hiberbia and Ben Nevis-Avalon reservoirs, which are 3,700 m and 2,400 m, respectively.

Because the Hibernia platform is in relatively shallow water – just 80 m deep – the odds of a large iceberg ever hitting the platform are extremely low. But the Hibernia platform was designed to withstand the impact of a one-million tonne iceberg with no damage, and can withstand contact with a six million tonne iceberg, estimated to be the largest that can drift into that water depth and only expected once in 10,000 years, with repairable damage.

RigZone