Fracture trace analysis involves several steps, each of them designed to add to the previous one, and culminate in a map of potential drilling locations in a fractured bedrock regime. Unlike many methods, fracture trace analysis relies upon several well-proven geologic and hydrogeologic practices to create this map, and reduce the risks of drilling a less than adequate water well.
The first steps in conducting a fracture trace analysis involve terrain analysis using aerial photography. Specifically, discernible linear features are mapped on the photographs, along with indications of recharge areas, and surface expressions of geologic interest relative to groundwater movement and quality. The second step is called “ground truthing” were in a geologist goes into the field to verify the features identified during the terrain analysis, along with discarding false positives (e.g. fence lines and old roads). The geologist will also prepare a basic geologic map, including the strike and dip of these features, in preparation of the next step.
Using the structural geology information obtained in the second step, the third step involves plotting the information using stereonets, from which the primary fracture systems orientation and inclination can be determined. Once these are plotted, a return to the field to focus on these primary fractures occurs. It is during the second mapping event, that the “Hydro-Potential” values of the fracture system are measured.
Having collected the “Hydro-Potential” value data, a final map is prepared of the potential drilling locations based upon likelihood of water, accessibility, and compatibility with future plans. With this map, the drilling operations can be directed to begin.