Production, transportation, and refining of heavy crude oil present special challenges compared to light crude oil. The largest reserves of heavy oil in the world are located north of the Orinoco river in Venezuela, the same amount as the conventional oil reserves of Saudi Arabia, but 30 or more countries are known to have reserves. Heavy crude oil is closely related to tar sands, the main difference being that tar sands generally do not flow at all. Canada has large reserves of tar sands, located north and northeast of Edmonton, Alberta.
Physical properties that distinguish heavy crudes from lighter ones include higher viscosity and specific gravity, as well as heavier molecular composition. Extra heavy oil from the Orinoco region has a viscosity of over 10,000 centipoise and 10° API gravity . Generally a diluent is added at regular distances in a pipeline carrying heavy crude to facilitate its flow.
The "heaviness" of heavy oil is primarily the result of a relatively high proportion of a mixed bag of complex, high molecular weight, non-paraffinic compounds and a low proportion of volatile, low molecular weight compounds. Heavy oils typically contain very little paraffin and may or may not contain high levels of asphaltenes.
Advanced technologies are mitigating the environmental impact via horizontal wells and increased energy efficiency, but, barrel for barrel, heavy crudes will likely always be more environmentally damaging than light crudes.
EPR and fluorescence spectroscopy in the photodegradation study of Arabian and Colombian crude oils.(electron paramagnetic resonance )
Jan 01, 2006; EPR and fluorescence spectroscopy were used to evaluate the degradation of crude oils of different origins that were submitted to...
WIPO PUBLISHES PATENT FOR "FLOW ADDITIVE FOR LIGHT OR HEAVY CRUDE OILS, USE OF THE ADDITIVE AND PROCESS TO IMPROVE THE EXTRACTION, PUMPING AND/ OR TRANSPORT OF LIGHT OR HEAVY CRUDE OILS" (BRAZILIAN INVENTOR)
Jan 26, 2012; GENEVA, Jan. 26 -- Publication No. WO/2012/000069 was published on Jan. 5. Title of the invention: "FLOW ADDITIVE FOR LIGHT OR...