WellCAD Basics - Advanced Logic Technology

150 - BOOK 1 - WELLCAD BASICS
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Deviation Channels:
Select the input channels for borehole azimuth and borehole tilt from the
corresponding drop down lists. Borehole azimuth must be measured clockwise from
Magnetic or True North in degrees. Tilt is the inclination of the well measured from
the vertical axis (TVD) in degree (Tilt = 0� vertical well, Tilt = 90� horizontal well).
Units:
Choose the units in which the coordinates for Northing, Easting and TVD are
measured. Possible options are meters and feet.
TVD:
The initial value for the TVD channel can be set to the top depth of the input
channel (Tilt). Tick the Top Depth Of Source Log option. If you want the initial
value to be zero or any other value, tick the Depth option and enter the desired
value.
The process will output a Well Log with the data being MD (measured depth) and
TVD (calculated). The TVD data can also be output as Depth Column Log. Tick
the corresponding option in the dialog box.
Method:
Choose one of the three algorithms to compute the coordinates:
Classic Tangential: Coordinates are calculated
from azimuth and tilt at the current position
(A). The next point of calculation (B’) is
reached stepping one sample rate (dL) in the
direction of the tangent calculated in point A.
One has to consider that the well path between
A and B may be curved and an error is made.