Horizontal Well Installations - Not Just For Large Projects

Hydrogeology, Geology, & Environmental Issues

Date posted: 02/04/15

When thinking about the use of horizontal/directional drilling -HDD- methods for environmental well installations, many consultants and owners have the perception that the technology is only useful for large, complex sites. The types of locations commonly considered to utilize HDD environmental wells include Department of Defense sites, manufacturing facilities, chemical plants and rail yards. Although many of those large complex sites are ideal for HDD well installations, horizontal well projects consisting of one to three short-shallow wells, are consistently being completed across the US. There are hundreds, if not thousands of small contaminated locations across the country that are being neglected because access is considered to be impossible. Most of these sites are located in highly urbanized areas where contamination is under occupied commercial/residential buildings and surface infrastructure such as streets and parks. DTD and other horizontal drilling contractors have small-footprint horizontal drilling systems that are ideal for sites like active or former UST releases and dry cleaners. The primary equipment can be placed in an area as small as a few parking spots, 30 feet by 50 feet. This includes the drill rig, drilling fluid mixing or pumping system, waste containment and materials storage. Another unfortunate perception is that horizontal remediation wells need to exit the ground and the well materials must be pulled back to the drill rig, requiring site access and work far from the rig up area. Again this is not reality. Blind wells in many geologic settings are routinely completed up to 300 feet in length using PVC screen and casing. By utilizing HDPE well materials, blind well installations up to 500 feet are possible. Please note that geology plays a role in blind well installations, and many times is the limiting factor when it comes to the ultimate length of the completion.