THG employee performing a Frequency Domain Electromagnetic (FDEM) Survey using a GF instruments CMD Explorer Terrain Conductivity Meter

Utility Mapping for New Gas Well Pads

As part of the development process for oil and gas well sites in rural areas of southwestern Pennsylvania, eastern Ohio and northern West Virginia, THG has conducted utility investigations at dozens of proposed well pad sites.  Accurately locating utilities on private sites prior to the start of construction minimizes safety concerns associated with encountering unknown subsurface utilities or obstructions and prevents delays during construction.  Additionally, considering the scrutiny oil and gas production companies tend to experience during operations in some regions, compiling base-line information and testing all parameters of operations helps to establish due diligence and develop positive relationships with locals and regulators alike.

Working with engineers and construction managers, THG developed an efficient and robust operating procedure for surveying proposed well sites for the presence of subsurface utilities, obstructions and other foreign structures.  The first step in our procedure is a full coverage Frequency Domain Electromagnetic Survey (FDEM) using multi-depth probes which establishes a base-line electromagnetic profile of the site and also helps to identify metallic utilities, building foundations and other subsurface features of interest.  This information is extremely valuable during the utility locating process but also for comparison with information that may be collected related to future incidents such as contaminant spills.

The second stage of THGs survey procedure consists of traditional utility locating operations including frequency conduction/induction electromagnetics, radio/60 Hz detection, traceable rodders for storm and sanitary lines, and Ground Penetrating Radar (GPR). Finally, THG compiles all of the data and creates a detailed report including our methods, discussions, conclusions and geo-referenced maps showing the locations of our findings on high resolution orthoimagery for easy correlation on site.


Frequency Domain Electromagnetic Survey (FDEM) data over well pad site.