Horizontal Remediation Wells
Industry analysts indicate that hundreds of horizontal remediation wells are installed each year. Applications for horizontal wells include air sparging, biosparging, bioventing, soil vapor extraction, landfill leachate collection, landfill gas collection, free product recovery, and horizontal soil sampling for site assessment.
Horizontal remediation wells are screened bores installed along or across subsurface contaminant plumes. They interact with the surrounding formation and are essential components of remediation systems. Horizontal wells can be used to extract liquids and vapors or to introduce air, reactive chemicals, or biological stimulants.
Horizontal wells differ from horizontal borings in that borings are not screened and provide only a conduit for water, gas, power, or fiber cables. Borings are passive and the placement of borings is less critical than horizontal wells. Borings do not interact with the formation; horizontal remediation wells do.
Horizontal remediation wells can be used in the remediation field to lower the cost of a project; access areas that cannot be accessed using vertical wells or trenches; and reduce the number of pieces of aboveground remedial equipment such as pumps, blowers, and carbon canisters. The drilling fluids, drill methods, development requirements, and other facets of drilling wells and horizontal well installation are vastly different from those associated with horizontal bores even though the same drill rig may be used for both. The Directional Technologies team is skilled and experienced at installing horizontal remediation wells properly and understands the differences between boring and horizontal remediation wells.
While there is no universally applicable optimum design for a horizontal well, a typical design employs 4″-diameter HDPE and 400′ of screened interval. Longer screened intervals generally require larger diameters. Shorter screened intervals can sometimes be installed with smaller diameter well materials.