Imaging Techniques for Geological Modeling

 Maps and Cross Sections : 

Most reservoir maps in the world use m.s.l.  as the reference. Depths of the layer increases away from 

the crest of the structure.

The reference is needed because the drilling rig can be on top of  a mountain or an offshore platform.

 In each case the measured depth of the same layer is different as the drilling reference is different.

Piratically any type of geologic data  can be represented on a map .Some of the  most useful maps are 

those that present clear pictures  of the distribution of geologic parameters .

A geologic  map is  an  example of this because  it shows the distribution of  individual rock 

formations   over the area of the map . 

Contour maps can illustrate thickness , facies , percentages , topography , and structure .They  show 

variations that are useful in interpreting the complete geology of an area or individual characteristics 

within the entire data structure . 

Contour  Maps : 

Data upon which numerical values can be placed  can be contoured , since contour  lines connect 

points  of equal value .Contour maps are important interpretive aids and can represent anything  from 

sequential geologic events to absolute values of individual parameters within single rock units .

1. Contour interval should adequately represent the data .Too large an interval overlooks some of the data and too small an interval clutters the map . 
2. Contour lines should honor the data and be properly spaced relative to them .
3. Contour lines should  be drawn smoothly and as parallel to each others as the data will allow .
4. Contour lines should never cross .Crossing contour lines are an impossibility. 
5. Contour lines  should be close together where gradients are steep and farther apart where gradients are shallow .
6. Contour lines  should be labeled . 

Geological Maps :

Geological maps can include as much or as little data as desired .Usually they include  formations and 

their contacts and the most prominent faults .However , geologic maps can also include topographic  

and structural  contours , as well as structural features .

Most geologic maps are colored .But data also can be represented by the use of symbols or different 

tones of gray . Geographic features are essential for purposes of location .

Cross Sections :

Structural , stratigraphic  and topographic information  can be portrayed on cross-sections  that

 reproduce horizontally represented map information in vertical section .

Maps represent information  in the plan  view and provide a graphic view of distribution .Cross-

sections present the same information in the vertical  view and illustrate vertical relationships such as 

depth , thickness , superposition , and lateral and vertical changes of geologic features .

Raw data for cross-sections  come from stratigraphic sections , structural data , well sample logs , 

cores , electric logs  , and structural , stratigraphic and topographic  maps . Datum for the cross-

sections is sea level .