Within the last 10 years the world has come to a point where the easily explorable oil deposits have now been found, and it is anticipated that such deposits will be depleted by the beginning of the Twenty-first Century. However, the increasing demand of man kind for energy has caused technologists to look into ways of find ing new sources or to reevaluat: e unconventional sources which, in the past, have not been economical. In this respect, heavy crude and tar sand oils are becoming important in fulfilling the world's energy requirements. What are heavy crude and tar sand oils? There is...