Discing Analysis

This document details Datarock’s Discing Analysis product.

Dependent Models

The outputs of the following models are used:

 

Model Name

Model Type 

Fracture Detection and Classification

Object Detection

Drillers Break

Object Detection

Fracture Mask

Instance Segmentation

 

Data Processing

The following steps are taken to determine the Weighted Joint Density of a given interval:

  1. Take the output of the fracture detection model, “simple” classes only

  2. Run a segmentation model to extract the fracture profile

disc-1

disc-2

disc-3

3. Measure the angle of each fracture with respect to the core axis

4. Identify potential discs by:

    1. Measuring the distance between each fracture, referred to as the disc size

    2. Checking the fractures on both sides of the disc have angles that are similar and near perpendicular to the core axis

Merge nearby discing regions if the depth between them is within the define threshold (see Product Configuration Options section below)

An example downhole plot can be seen below.

downhole-1

Product Configuration Options

The following parameters can be configured as part of the discing calculation:

Configuration 

Options

Maximum size of a disc

Threshold can be set to any value.

Default value is 30mm

Minimum number of discs required to define a discing region

Threshold can be set to any value.

Default value is 3 discs

Maximum distance between adjacent discing regions to merge into one region

Threshold can be set to any value.

Default value is 300mm

 
Output Data

The output data is based on identified intervals of discing.

User Data

User data is no necessary for this product.

Data Output

Results from this product is delivered in a batch nature.

Integration of the required technologies into Datarock production is ongoing.

The available CSV files include the following:

  • ProjectID_HoleID_discing.csv

The CSVs contains the following headers: 

File Header 

Description 

hole_id

Customer’s Hole ID

depth_from

Start depth of discing discing region

depth_to

End depth of identified discing region

DISC_COUNT

Number of discs in region

AVG_DISC_SIZE_m

Average length (m) of discs within the region

AVG_ANGLES

Average angle of the of discs with respect to the core axis

GOOD_ANGLE_COUNT

Count of angles within a discing region that are within threshold 

avg_abs_diff_angles

The average of the absolute difference between each discs two angles (LHS & RHS) within a region. This is a measure of the consistency of the fracture angles.

C1

Confidence metric based the fracture angles. Calculated using proportion of near perpendicular fractures within a discing region.

C2

Confidence metric based on the consistency of the fracture angles within a region. Calculated based on the average deviations of the fracture angles with a discing region.

C3

Confidence metric based the number of discs within a region. Calculated based on number of discs in a discing region. More discs indicate higher chances of the region being a truly discing region.

Confidence

Overall confidence metric for a given region

 

Product Limitations

 

Limitations 

Comments 

Based on open joints only

Only open joints are measured, meaning the discing has to have developed enough

Reliance on open joint detections

This product relies on assessment of measured angles of individual open joints/fractures. However, if a region contains intense discing that has broken/collapse as a result of the drilling or core handling, the fracture detection model will not detect each individual fracture. This is likely to result in a missed discing region (or portion of a region).

 

Document Version

 

Version

Date 

Author 

Rationale

1

5 April 2024

S Johnson

Initial release