"Heavy crude" refers to a type of oil that is thick and sticky, making it difficult to extract and refine. It contains more impurities than lighter oils and requires additional processing to make it usable. Full definition
The company also produces conventional oil, heavy crude oil, and natural gas. (climatecrocks.com)
Perhaps not so ironically, the House vote on Terry's bill happened on the one - year anniversary of the Kalamazoo River in Michigan being fouled with 800,000 - plus gallons of heavy crude from oil sands. (insideclimatenews.org)
The pipeline would bring more than 800,000 barrels per day of heavy crude from Canada's oil sands into Nebraska (scientificamerican.com)