US Patent 12078771 Obstacle detection systems and methods

A system and method of detecting subsurface karst features includes receiving surface mapping data. A potential surface pad location can be identified in view of the surface mapping data. A resistivity survey for the potential surface pad location can be designed. The resistivity survey can include at least one long line extending through a surface hole for each of one or more wellbores in the potential surface pad location, and a short line extending through the surface hole of one of the one or more wellbores, each short line intersecting the long line substantially at the surface hole of one of the one or more wellbores. High resistivity areas exceeding approximately 150 Ohm per meter can be identified as sub surface karst features within the resistivity survey.