Fracture topology refers to the structural relationships and connectivity between individual fractures in a rock mass. Understanding these relationships is essential for characterising fluid flow, mechanical stability, and reservoir behaviour in subsurface formations. Unlike traditional fracture analysis, which focuses on orientation and frequency, fracture topology emphasises how fractures intersect, terminate, or remain isolated — providing a deeper insight into the connectivity and complexity of fracture networks.

The fracture topology functionality in WellCAD enables systematic interpretation and classification of fractures in borehole data. Fractures are categorised into three distinct node types based on their structural relationships: isolated (green), intersecting (blue), and terminating (red). Through manual fracture identification, WellCAD automatically assigns appropriate node classifications, creating a detailed visual representation of the fracture network. This classification system establishes the analytical foundation for understanding subsurface connectivity, which is critical in fields like hydrogeology, geomechanics, and reservoir engineering.

The interpreted fracture networks generate comprehensive statistical outputs, including node distribution analysis, branch connectivity metrics, and line density calculations. These statistics can be displayed as 1D logs or ternary plots and compared across different depth intervals. This methodology covers the extraction of standardised PXY statistics (P10, P11, P21, P32, and P33), which are essential for quantitative modelling. These values can be exported to third-party software, such as those used for Discrete Fracture Network (DFN) modelling, providing a robust foundation for advanced analysis and decision-making.

This video tutorial provides step-by-step implementation of a fracture topology workflow in WellCAD, from initial fracture identification to statistical analysis and data export.