Curved Borehole Oriented Core

The Curved Borehole Oriented Core Traverse Type should be used when you have:

• A non-linear borehole with curvature defined by a survey file
• Unprocessed oriented core with joint orientations recorded as local Alpha / Beta angles on the core.

The Curved Borehole Oriented Core Traverse option allows you to process the oriented core data into true Dip/DipDirection or Strike/Dip; and to apply the Terzaghi Weighting to the joints, by determining the orientation of the borehole for each joint measurement and applying the appropriate weighting factor based on the relative orientation of the borehole and the joint plane.

If you have processed oriented core taken from a curved borehole (e.g., already processed using Dips or other application), or if measurements are processed from Televiewer, then you can use the Curved Borehole Televiewer option rather than the Curved Borehole Oriented Core option, to apply the Terzaghi Weighting to the measurements.

Traverse ID

For a Curved BH Oriented Core Traverse, the default Traverse ID will have a "CBH-OC" prefix (e.g., CBH-OC1, CBH-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 Curved 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 Curved 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 Curved Borehole Oriented Core Traverse is Orient 1 + Survey File .

Example of Traverse Information dialog with one Curved BH Oriented Core Traverse

• The Survey File data is entered in the Survey Data tab in the Traverse Information dialog.
• Orient 1 has the same definition as for a Linear Borehole Oriented Core Traverse. See below for details.

ORIENT 1

For a Curved Borehole Oriented Core Traverse, the Orient 1 value has the same definition as for a Linear Borehole Oriented Core Traverse. It is the angle from the top of core to the Reference Line, measured clockwise looking in the down core direction. See the Linear Borehole Oriented Core topic for details.

NOTE: For a Curved Borehole Oriented Core Traverse, it is assumed that the value of Orient 1 is constant for the entire length of the curved borehole Traverse. If this is not the case, then you will have to define a separate Traverse for each change in the value of Orient 1 along a curved borehole.

Collar Data

For Curved Borehole Oriented Core Traverses, the collar data is entered in the Collar Data tab in the Traverse Information dialog.

1. Select the Collar Data tab.
2. Select the Add button to add the required number of rows. This should correspond to the number of Curved BH Oriented Core Traverses defined under the Traverses tab.
3. Enter the Traverse ID for each Traverse. The Traverse IDs should be the same as entered under the Traverses tab. You can use Copy/Paste to transfer the Traverse IDs.
4. Enter the XYZ values of the collar locations (X = Easting, Y = Northing, Z = Up).
5. Enter the Total Depth (length) of each Curved BH Oriented Core Traverse.

NOTE: The Collar Data is not currently used in the Dips analysis, however it will be used for filtering and viewing purposes in a future update.

Survey Data

For Curved Borehole Oriented Core Traverses, the survey data is entered in the Survey Data tab in the Traverse Information dialog.

1. Select the Survey Data tab.
2. Select the Add button to add the required number of rows. This should equal the total number of survey readings for ALL Curved Borehole Traverses that you are defining.
3. Enter the Traverse ID for each survey point. Traverse IDs entered in the Survey tab should correspond to those entered in the Traverse tab and Collar tab.
4. Enter the Distance readings for the survey points.
5. Enter the Trend / Plunge readings for the survey points.

NOTE:

• The orientation format convention for Survey Data is always Trend / Plunge. This is equivalent to the standard Azimuth / Dip terminology commonly used to record borehole survey orientations.
• The conventions used for Plunge (e.g., positive or negative) are determined in the Settings dialog, see below for details.
• For multiple Traverses, data is entered consecutively in the ID, Distance, and Trend / Plunge columns for all Traverses.

Curved Borehole Options

For Curved Borehole Traverses, if you select the Settings button at the bottom of the Traverse Information dialog, the following options are available.

PLUNGE OPTIONS (SURVEY DATA)

There are two options for defining the Plunge convention for Survey Data:

• Negative = Down, Positive = Up
• Positive = Down, Negative = Up

If you choose the Negative = Down option, then negative plunge values will represent the downward direction for the Survey Data.

If you choose the Positive = Down option, then positive plunge values will represent the downward direction for the Survey Data.

NOTE: This option only applies to Survey Data Plunge values entered for curved Traverses in the Traverse Information dialog. It does NOT affect the data conventions used in the main Dips spreadsheet.

DE-SURVEY OPTIONS

For analysis purposes, curved borehole surveys in Dips are represented by a series of linear segments.

There are two possible de-survey options:

• The Linear, at segment ends option, will directly connect the survey points with linear segments.
• The Linear, at mid-points option, will assume each survey point is the mid-point of a linear segment, and generate the segments accordingly.