Linear Borehole Oriented Core

NOTE: The Linear Borehole Oriented Core Traverse type in Dips is exactly equivalent to the Borehole Traverse type in Dips version 6 and earlier. Only the name has been changed for consistency with the new curved borehole Traverse type names in Dips.

The Linear BH Oriented Core Traverse Type should be used when you have oriented core taken from a linear borehole (i.e., a borehole which is assumed to have a constant Trend / Plunge orientation for the length of the borehole). If the mapping has been conducted on core recovered from a linear borehole, then three orientations are required in the Traverse Information dialog to define the Linear BH Oriented Core Traverse:

000; 000; 000 (Orient 1 / Orient 2 / Orient 3)

If you have oriented core from a non-linear (curved) borehole which has curvature defined by a survey file, then you should use the Curved BH Oriented Core Traverse type rather than the Linear BH Oriented Core option.

Traverses Tab

Traverse ID

For a Linear BH Oriented Core Traverse, the default Traverse ID will have an "LBH-OC" prefix (e.g. LBH-OC1, LBH-OC2, ...) when you initially add/create Traverses. After adding Traverses you can change the default ID values to any numeric or alpha-numeric values.

Data Format

For a Linear Borehole Oriented Core Traverse, the Data Format is always Alpha / Beta, which refers to the local angles Alpha and Beta for discontinuities logged on oriented core.

In the Dips Grid Data view you must enter Alpha / Beta values in the Orientation Columns for Linear BH Oriented Core Traverses. This overrides the Global Orientation Format, which is not applicable for Traverses which use oriented core. See the oriented core data topic for the definitions of Alpha / Beta.

Traverse Format

The Traverse Format for a Linear BH Oriented Core Traverse requires three values: Orient 1/2/3 as described below.

Example of Traverse Information dialog with two Linear BH Oriented Core Traverses

Orient 1

Orient 1 is the angle from the top of core to the reference line (measured clockwise looking in the down core direction). Use Orient 1 = 0 if the borehole is vertical.

The Orient 1 value entered in the Traverse Information dialog for a borehole Traverse, is required because the Beta angle measured for each discontinuity on the core, must be measured with respect to some reference line along the length of the core.

See the Borehole Orientation Data Pairs topic for more info.

If the reference line is the top of the core (i.e., a line along the physical top of the core), then Orient 1 = 0. If the reference line is along the bottom of the core, then Orient 1 = 180 degrees. These are the most common situations. However, Dips allows the reference line to be located at any position with respect to the top of the core, hence an “arbitrary” value can be entered, if the reference line is at some arbitrary position (e.g., 45 degrees from the top line of the core).

The Orient 1 value serves to orient the rotational position of the core, with respect to the borehole. Without the reference line, you do not know how the core was positioned with respect to the borehole, therefore this is always a required input for oriented core analysis.

NOTE: For a vertical borehole, there is no longer a “top” or “bottom” of core, therefore you should enter Orient 1 = 0, and the Orient 3 value is used to determine the position of the reference line. As stated in the help for Orient 3: For a vertical borehole, use the clockwise angle from true north to the reference line, looking along the direction of borehole advance.

Orient 2

Orient 2 is the inclination of the borehole axis from the zenith. Use Orient 2 = 0 for a borehole oriented vertically upwards, and Orient 2 = 180 if the borehole is oriented vertically downwards.

Orient 3

Orient 3 is the azimuth of the borehole measured from true north. For a vertical borehole, use the clockwise angle from true north to the reference line, looking along the direction of borehole advance.

For a vertical borehole, the Orient 3 value serves to define both Orient 1 and Orient 3.

For a vertical borehole, Orient 1, as defined in Dips, cannot technically be defined because there is no "top" of core, since the core is vertical. That is, there is no "top" line from which to measure an angle to the reference line. So you should simply enter Orient 1 = 0 since it is not actually used.

Orient 3 serves both purposes of defining the azimuth direction, and orienting the core within the borehole, by defining the orientation of the Reference Line on the core, with respect to north. Combined with the fact that the hole is vertical, that gives you all the information you need to correctly orient the core within the borehole.

For a vertical borehole, Orient 2 is either 0 or 180 degrees, according to whether the borehole was drilled downwards ( Orient 2 = 180) or upwards ( Orient 2 = 0).

Collar Data Tab

The Collar Data tab allows you to input the corresponding collar data for the borehole. See the Collar Data topic for more information.