Changes

* θ = contact angle or [[wettability]], degrees

* θ = contact angle or [[wettability]], degrees

Displacement pressures measured in the air-mercury system are then converted to the hydrocarbon–water system at subsurface conditions. To convert, we must know the temperature, pressure, [[wettability]], and coefficient of interfacial tension for the hydrocarbon phase. These parameters are commonly inferred from the composition, [http://www.enggcyclopedia.com/2012/03/gas-oil-ratio-gor/ gas–oil ratio], and [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=API%20gravity API gravity].<ref name=ch10r67 /><ref name=ch10r87 /> For the air–mercury system, the wettability of mercury is 140° (cos 140 = 0.766). The coefficient of interfacial tension for mercury is 485 dynes/cm.<ref name=ch10r87 />

Displacement pressures measured in the air-mercury system are then converted to the hydrocarbon–water system at subsurface conditions. To convert, we must know the temperature, pressure, [[wettability]], and coefficient of interfacial tension for the hydrocarbon phase. These parameters are commonly inferred from the composition, [http://www.enggcyclopedia.com/2012/03/gas-oil-ratio-gor/ gas–oil ratio], and [[API gravity]].<ref name=ch10r67 /> <ref name=ch10r87 /> For the air–mercury system, the wettability of mercury is 140° (cos 140 = 0.766). The coefficient of interfacial tension for mercury is 485 dynes/cm.<ref name=ch10r87 />

==See also==

==See also==