Assessment of environmental implications of abandoned oil and gas wells

A detailed study was made of the potential for abandoned oil and gas wells in the Lower Tuscaloosa sand of Mississippi and Louisiana to act as conduits for movement of saline water from the Lower Tuscaloosa into underground sources of drinking water (USDW's). Finite-difference numerical modeling determined the extent that water might be forced from the Lower Tuscaloosa sand into a USDW as a result of injection into the Lower Tuscaloosa. Within the range of conditions modeled, water from the Lower Tuscaloosa never traveled into a USDW. On the basis of the modeling, the authors concluded that it is unlikely that abandoned oil and gas wells in the Lower Tuscaloosa would serve as conduits for water movement from the trend into a USDW. The procedures developed in this study should be readily applicable to analysis of the potential for abandoned wells to act as pathways for contaminant flow into USDW's in other oil and gas producing areas of the country.