Changes

  | isbn    = 0-89181-602-X

  | isbn    = 0-89181-602-X

}}

}}

Resistivity, sonic, and density logs (as well as some others) can give clues to the presence of over- or underpressure. Shale sections are best for analysis of logs for abnormal pore pressure. Because of their low permeabilities, shales do not equilibrate pressure with the mud column in the well bore. Selecting only the purest shales minimizes the effects of mineral variation, multiple phases, fluid composition, and fluid distribution. That leaves only [[porosity]] as the major variable within shale sections. Because porosity is related to compaction, porosity measurements from well logs can be calibrated to fluid pressure in the pore systems.

[[Basic open hole tools#Resistivity|Resistivity]], sonic, and density logs (as well as some others) can give clues to the presence of over- or underpressure. Shale sections are best for analysis of logs for abnormal pore pressure. Because of their low permeabilities, shales do not equilibrate pressure with the mud column in the well bore. Selecting only the purest shales minimizes the effects of mineral variation, multiple phases, fluid composition, and fluid distribution. That leaves only [[porosity]] as the major variable within shale sections. Because porosity is related to compaction, porosity measurements from well logs can be calibrated to fluid pressure in the pore systems.

==Log of drilling rate==

==Log of drilling rate==