Changes

==Rate measurements==

==Rate measurements==

Rate measurements of [[Hydrocarbon migration|migration]] are seldom made because of the uncertainty associated with migration length, cross-sectional area, and time interval. Linear rate estimates of gas-phase migration in the upper [[length::200 m]] of sedimentary basins are as high as tens of meters per day, based on known times of injection of gas into storage reservoirs and subsurface coal burns. Estimates of vertical seepage velocities over larger areas are between 75 and 300 m/year. Oil volume rate estimates of 50 m³ (300 bbl) per year have been made in the marine environment by collecting bubbles. These rates clearly indicate separate phase migration along multiple narrow migration pathways.

Rate measurements of [[Hydrocarbon migration|migration]] are seldom made because of the uncertainty associated with migration length, cross-sectional area, and time interval. Linear rate estimates of gas-phase migration in the upper [[length::200 m]] of sedimentary basins are as high as tens of meters per day, based on known times of injection of gas into storage reservoirs and subsurface [[coal]] burns. Estimates of vertical seepage velocities over larger areas are between 75 and 300 m/year. Oil volume rate estimates of 50 m³ (300 bbl) per year have been made in the marine environment by collecting bubbles. These rates clearly indicate separate phase migration along multiple narrow migration pathways.

==Maximum rates==

==Maximum rates==