Changes

  | part    = Predicting the occurrence of oil and gas traps

  | part    = Predicting the occurrence of oil and gas traps

  | chapter = Predicting reservoir system quality and performance

  | chapter = Predicting reservoir system quality and performance

  | frompg  = 9-1

  | frompg  = 9-5

  | topg    = 9-156

  | topg    = 9-5

  | author  = Dan J. Hartmann, Edward A. Beaumont

  | author  = Dan J. Hartmann, Edward A. Beaumont

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm

==Waste and transition zones==

==Waste and transition zones==

A '''waste zone''' may be found at the top of a reservoir, just below the seal, if there is a decrease in the size of the pore throat radii of the reservoir. It generally produces hydrocarbon and water on a production test.<ref name=Schowalter_1979>Schowalter, T. T., 1979, [http://archives.datapages.com/data/bulletns/1977-79/data/pg/0063/0005/0700/0723.htm?q=%2BtitleStrip%3Amechanics+titleStrip%3Asecondary+titleStrip%3Ahydrocarbon+titleStrip%3Amigration+titleStrip%3Aentrapment Mechanics of secondary hydrocarbon migration and entrapment]: AAPG Bulletin, v. 63, no. 5, p. 723-760.</ref>  

A '''waste zone''' may be found at the top of a [[reservoir]], just below the [[Seal capacity of different rock types|seal]], if there is a decrease in the size of the pore throat radii of the reservoir. It generally produces hydrocarbon and water on a production test.<ref name=Schowalter_1979>Schowalter, T. T., 1979, [http://archives.datapages.com/data/bulletns/1977-79/data/pg/0063/0005/0700/0723.htm?q=%2BtitleStrip%3Amechanics+titleStrip%3Asecondary+titleStrip%3Ahydrocarbon+titleStrip%3Amigration+titleStrip%3Aentrapment Mechanics of secondary hydrocarbon migration and entrapment]: AAPG Bulletin, v. 63, no. 5, p. 723-760.</ref>  

A '''transition zone''' is located at the base of a reservoir and forms as a result of a loss of buoyancy pressure in the hydrocarbon phase. Pore throat diameter and fluid densities determine its thickness. It generally produces hydrocarbon and water on a production test.

A '''transition zone''' is located at the base of a reservoir and forms as a result of a loss of [[buoyancy pressure]] in the hydrocarbon phase. [[Connectivity_and_pore_throat_size#Characterizing_pore_systems_by_size|Pore throat diameter]] and fluid densities determine its thickness. It generally produces hydrocarbon and water on a production test.

==Free water level==

==Free water level==

{{main|Free water level}}

{{main|Free water level}}

The '''free water level''' is located at the base of a hydrocarbon column and the transition zone. Above this level, the reservoir produces water alone, hydrocarbon and water, or hydrocarbon alone on a production test. Below this level lies the aquifer of a water-drive reservoir system. It produces water only. Zero buoyancy pressure exists at this level or below.

The '''free water level''' is located at the base of a [[hydrocarbon column]] and the transition zone. Above this level, the reservoir produces water alone, hydrocarbon and water, or hydrocarbon alone on a production test. Below this level lies the aquifer of a [[Drive_mechanisms_and_recovery#Water_drive|water-drive]] reservoir system. It produces water only. Zero [[buoyancy pressure]] exists at this level or below.

==References==

==References==

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting reservoir system quality and performance]]

[[Category:Predicting reservoir system quality and performance]]