Dealing with fault control points on branch lines

Fault cutoff line editing allows you to drag control points up and down the fault sticks to reposition the intersection line of a horizon with respect to a fault. A control node is shown in the image below along with the fault stick. In most cases, the fault sticks extend across the entire fault. In locations in which the fault or interest is cut by another fault, you may come across a situation in which the fault sticks of interest are being truncated by the other fault. This appears to limit your ability to move the nodes into the position you want.

Fault Cutoff Line editing involves moving the control points of the fault cutoff lines along the fault sticks. The selected blue node can be dragged along the red sub vertical fault stick    click to enlarge

Control points with are on a fault stick that is being cut off by another fault have a limited ability to be moved. You cannot move the blue node upwards due to the truncated faults stick    click to enlarge

Where encountered

  • model > 3D Structure > Fault Cutoff Line Edits

Cause

The fault sticks of the fault of interest are being truncated by another fault.

How to fix the issue

You should move the control nodes into the desired position as shown in the second image. Leave out any nodes that cannot be placed into the desired position.

It is important that these nodes are set to 'unedited'. Do this by right-clicking on the nodes and selecting Delete Edits/Node. The node’s color will change to gray when highlighting edits. This should be done for all nodes which cannot be moved.

Result

The unedited nodes are 'free to move'. The edited fault cutoff line nodes will determine the geometrical changes. Nodes which are marked as 'unedited' and which are not locked will changed in accordance to the other nodes when the user selects to apply the changes. This will move the unedited nodes into their proper position (see image below).

The 'unedited' node of the fault cutoff line has been ignored. Upon the reconstruction of the surfaces, the edited control nodes will govern the geometry. Note that as the original 'unedited' node would have ended up on the other side of the fault and been removed from intersection line    click to enlarge