Rotary driven well drilling rigs can be used to create boreholes of various sizes for a variety of purposes. For example, such rotary driven rigs can be used to form boreholes for geothermal heat loop installation. Geothermal heat loop systems use the earth as a constant source of heat to be extracted by a heat pump. Extracting heat from the ground, which can have a near constant temperature, can be more efficient than extracting heat from the air, which can be subject to extreme temperature variations. Such geothermal systems can reduce heating/cooling costs and are environmentally friendly by reducing the use of fossil fuels to heat/cool homes and buildings, for example.
Geothermal heat loops can be installed to heat and/or cool homes, schools, churches, commercial buildings, etc. The heat loop installation process can involve drilling a number of boreholes into which the loops are placed. The boreholes are often drilled using wet/air rotary drill rigs. Many current rotary well drilling rigs consist of boring machinery mounted atop large trucks that can weigh 15 tons or more exerting a ground contact pressure of 45-50 pounds per square inch (psi).
Operating current rotary well drilling rigs can be damaging to property. The heavy truck mounted drilling rigs can leave large piles of cuttings and muddy streams of run-off water along with numerous tire ruts throughout a drilling area. The damage can be exacerbated as current drilling rigs often drill a single borehole while having to move the entire truck to another location to drill subsequent boreholes.
As such, it can be especially undesirable to use current wet/air rotary drilling rigs in order to drill boreholes in areas where landscaping can be important, such as in residential areas or around school playgrounds, for example.