ABSTRACT

Underground injection is the most widely practised technology used to dispose of oilfield brines in the State of Louisiana, which contains almost 4,000 brine injection wells that dispose an estimated one billion barrels of brine each year. Louisiana has had no known contamination of a public water supply from underground injection of such brines; however, the magnitude of this activity presents a potential for such if proper disposal practices are not followed.

Following the earliest discovery of oil, the protection of groundwater aquifers from underground injection has been improved through technical advances developed within the petroleum industry. Although earliest use of underground injection technology began with an economic incentive, underground injection of oilfield brines has progressed to become a method providing environmental safety to ground-water aquifers. Complex reservoir modeling, developed for use in secondary and enhanced recovery techniques, has been applied for simulation of pressure effects and vertical migration potential for underground injection reservoirs. Conventional well designs that allow monitoring of well conditions have replaced older, unreliable designs. Improvements in wireline logging have enabled the capability of testing the isolation of injected brines from vertical movement along the well bore.

The environmental safety of underground injection has been improved over many years of technical advance in the petroleum industry. Stimulated by Federal and State regulations, cooperative industry officials are continuing to use technical improvements to assure the protection of ground-water aquifers. This continuance is critical to prolonged development and exploration of Louisiana's mineral resources.