Use of TDR for Detection of Fluid Hydrocarbons in the Geoenvironment

Early detection and location of fluid hydrocarbon leakage in the geoenvironment would significantly reduce the environmental impact, health and safety hazards, and remediation costs. The technical feasibility of a real-time detection and leak location technique for fluid hydrocarbons in the geoenvironment using the principles of time-domain reflectometry (TDR) has been investigated in a laboratory study. The measurement sensitivity of the technique was evaluated experimentally using a P3-500 JCAM109 cable made by CommScope in the parallel-wire configuration for systematic variations of fluids, leak configurations, and backfill materials. As the contrast in dielectric constants between fluid hydrocarbons and the air voids of soil is very small, it is necessary to develop an innovative data processing technique to amplify the contrast and to enhance the detectability of fluid hydrocarbon leakage in the subsurface. The results of the experimental investigation and the details of the innovative data processing technique are presented in this paper. The results indicate that the TDR technique using a commercially available cable can successfully detect and locate fluid hydrocarbon leaks in different backfill materials using the new data processing technique.