When it comes to unconventional natural gas and gas resources, you might immediately think of the continuous supply of coal and shale gas. But there is another lower-level energy source, which has over 15% of the total global unconventional oil and gas reserves and is a "moderate" energy source - that is, oil sands.
Oil sands, also known as "peat sands" or "mudstone sands", are mainly composed of asphalt, sand, mineral-rich clay, and contain approximately 6 - 12% asphalt, 80 - 90% useful minerals (such as sand and clay), and the remaining 3 - 5% water. Oil sands have the same production characteristics as hard deposits, as well as the formation characteristics of petroleum residues.