Canadian Pacific Railway Ltd (CP.TO:Quote) expects demand to ship oil by rail from the prolific Bakken field to continue to rise, with most of the crude destined for Gulf of Mexico refineries, the railway's executives said on Tuesday.

The company, whose lines run through the Bakken field in North Dakota and southern Saskatchewan, says crude-by-rail demand is now at about 13,000 carloads per year, or 8.5 million barrels. In June, the company said demand, on an annualized basis, was about 8,000 carloads, or 5.2 million barrels.

Fred Green, chief executive of Canada's No. 2 railway, said in an interview the line could eventually ship 70,000 carloads, or 45.5 million barrels, annually from Bakken field.

The company is shipping the oil in 80-unit trains, with about 80 percent of shipments headed for Gulf of Mexico refineries. However new investments by the railway will allow it to increase the size of its unit trains to 100 tank cars, Green said.