Changes

[[file:enhanced-oil-recovery_fig4.png|300px|thumb|{{figure number|4}}Schematic diagram of ''in situ'' combustion. The mobility of oil is increased by reduced viscosity caused by heat and solution of combustion gases. © U.S. Department of Energy, Bartlesville, Oklahoma.]]

[[file:enhanced-oil-recovery_fig4.png|300px|thumb|{{figure number|4}}Schematic diagram of ''in situ'' combustion. The mobility of oil is increased by reduced viscosity caused by heat and solution of combustion gases. © U.S. Department of Energy, Bartlesville, Oklahoma.]]

All thermal recovery processes involve the use of heat to accelerate the oil recovery process. The heat can be generated at the surface and injected into the reservoir, as in the case of steam injection ([[:file:enhanced-oil-recovery_fig3.png|Figure 3]]), or generated in the reservoir by injecting a fluid such as air that is combustible with the in-place oil ([[:file:enhanced-oil-recovery_fig4.png|Figure 4]]). The choice of which technique to use to add thermal energy to the reservoir depends on an analysis of the oil reservoir and the economics of generating the energy. However, a major goal of all thermal methods is to reduce the viscosity of the in-place oil. For most thermal processes, this is accomplished by heating a very [[heavy oil]] ([[API gravity]]).

All thermal recovery processes involve the use of heat to accelerate the oil recovery process. The heat can be generated at the surface and injected into the reservoir, as in the case of steam injection ([[:file:enhanced-oil-recovery_fig3.png|Figure 3]]), or generated in the reservoir by injecting a fluid such as air that is combustible with the in-place oil ([[:file:enhanced-oil-recovery_fig4.png|Figure 4]]). The choice of which technique to use to add thermal energy to the reservoir depends on an analysis of the oil reservoir and the [[economics]] of generating the energy. However, a major goal of all thermal methods is to reduce the viscosity of the in-place oil. For most thermal processes, this is accomplished by heating a very [[heavy oil]] ([[API gravity]]).

In a thermal flood, much effort is devoted to treating the boiler water and the stack gases resulting from the burning of produced oil or gas to generate heat. Because of environmental considerations, this usually limits the technique to unpopulated areas.

In a thermal flood, much effort is devoted to treating the boiler water and the stack gases resulting from the burning of produced oil or gas to generate heat. Because of environmental considerations, this usually limits the technique to unpopulated areas.