Module 3 Flashcards
How can you represent 3D in a 2D map?
contour map
representing 3D on a 2D map
criterion surface (real) continuous (3D) sample (real data) discontinuous (discrete) inferred surface (constructed) continuous contoured (map) continuous (2D)
Limiting factor when describing any phenomena
number of control points (the more the better)
density of control points relative to size and complexity
locations of control points in relation to principal features of the form
error in data values (precision withi which they are determined.
Rules and conventions of contour mapping
- contour line connects points of equal value
- spacing represents rate of change (aka slope) of the surface
- closed contours show extremes (highs or lows)
- lines cannot cross
datum
an arbitrary surface (ex. sea level. All formation tops are referenced to a daum before being used in structure map or structure cross-sections
can stratigraphical cross sections be stratigraphic or structural?
you can have 2 values with 2 different datums
isopach (definition)
A contour that connects points of equal thickness. Commonly, the isopachs, or contours that make up an isopach map, display the stratigraphic thickness of a rock unit as opposed to the true vertical thickness. Isopachs are true stratigraphic thicknesses; i.e., perpendicular to bedding surfaces.
isopach thickness
how is it calculated?
calculated from subtracting one formation top from another
facies map (definition)
isopach map designed to show distribution of sedimentary facies within a designated geological unit.
seismic maps
seismic maps either produce time structure or isochones
How are seismic maps in TWT converted to depth ?
using interval velocities derived from NMO velocities using DIX formula
How are major petroleum regions defined?
defined by: geologic parameters geologic age facies structure
