Viscosity, critical fuel oils

Heavy fuel oil is used by marine vessels, power plants, and industrial facilities for heating and processing. The critical specifications are the viscosity and the sulfur content. 

Lubricity is a term used to describe the ability of a fluid to minimize friction between, and damage to, surfaces in relative motion under load. Fuel helps to lubricate and prevent wear of high-pressure fuel injection pump components, especially under boundary lubrication conditions. Boundary lubrication is defined as a condition whereby friction and wear between two surfaces in relative motion are determined by the properties of the surfaces and the bulk properties of the contacting fluid. The bulk viscosity of the fuel or oil is not a critical factor under boundary lubrication conditions. 

While geological sequestration will build generally on the totality of experience with fossil fuel extraction, it will be most directly built on current practice of CO2 injection for enhanced oil recovery (EOR). Conventional extraction methods typically leave substantial oil in place. This oil may be extracted using EOR. Carbon dioxide injection (or flooding in industry jargon) is particularly effective because, as an organic solvent, the CO2 acts to reduce the viscosity of the residual oil and in addition causes the oil to expand thus helping to free it from the porous rock in which it is embedded. Typical EOR floods operate at pressures above the critical point of CO2 so that fluid flow is facilitated by the absence of a liquid-gas interface. 

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