Use of horizontal wells for environmental remediation

Unocal has begun evaluating the use of low cost horizontal wells installed with utility boring equipment for environmental remediation applications. The authors are currently performing pilot tests with single or multiple horizontal wells for applications involving soil vapor extraction, air sparging, air stimulated in-situ bioremediation, soil fracturing, and groundwater/free product recovery. Although the results of the evaluation are not complete, this paper describes the applications, methods being employed to evaluate the benefits and some preliminary field data at gasoline service stations in California, North Carolina and Ohio