Changes

If the object of the cross section is to show lateral and vertical details of the stratigraphy, log properties are of utmost importance.

If the object of the cross section is to show lateral and vertical details of the stratigraphy, log properties are of utmost importance.

Typically the [[Basic open hole tools#Spontaneous potential|SP]] or [[Basic open hole tools#Gamma ray|gamma ray]] log and one [[Basic open hole tools#Resistivity|resistivity log]] are displayed ([[:file:geological-cross-sections_fig2.png|Figure 2]]). [[Porosity]] logs may also be important, and if seismic data are part of the cross section, the sonic log is a critical tool to demonstrate the velocity structure, and consistency of conversion of time to depth.

Typically the [[Basic open hole tools#Spontaneous potential|SP]] or [[Basic open hole tools#Gamma ray|gamma ray]] log and one [[Basic open hole tools#Resistivity|resistivity log]] are displayed ([[:file:geological-cross-sections_fig2.png|Figure 2]]). [[Porosity]] logs may also be important, and if [[seismic data]] are part of the cross section, the sonic log is a critical tool to demonstrate the velocity structure, and consistency of conversion of time to depth.

Lines connecting correlative formation or zone tops between wells will show the lateral variation in thickness of these units. If it is important for the display to show exact correlations on logs, these lines should be drawn horizontally across the log display and angled between the edges of adjacent well displays, such as shown in [[:file:geological-cross-sections_fig2.png|Figure 2]]. Straight lines connecting the centers of the well displays may be more appropriate to provide a better representation of the thickness variations of units between wells. If thickness variations or the geometry of units is paramount in importance, then the logs can be reduced in scale so as to form a background or overlay to the formation data. Alternatively, they can be omitted entirely, and well courses can be represented as line segments, as shown in [[:file:geological-cross-sections_fig1.png|Figure 1b]].

Lines connecting correlative formation or zone tops between wells will show the lateral variation in thickness of these units. If it is important for the display to show exact correlations on logs, these lines should be drawn horizontally across the log display and angled between the edges of adjacent well displays, such as shown in [[:file:geological-cross-sections_fig2.png|Figure 2]]. Straight lines connecting the centers of the well displays may be more appropriate to provide a better representation of the thickness variations of units between wells. If thickness variations or the geometry of units is paramount in importance, then the logs can be reduced in scale so as to form a background or overlay to the formation data. Alternatively, they can be omitted entirely, and well courses can be represented as line segments, as shown in [[:file:geological-cross-sections_fig1.png|Figure 1b]].