An Area-of-Review Variance Study of the East Texas Field


The East Texas oil field, discovered in 1930 and located principally in Gregg and Rusk Counties, is the largest oil field in the conterminous United States. Nearly 33,000 wells are known to have been drilled in the field. The field has been undergoing water injection for pressure maintenance since 1938. As of today, 104 Class II salt-water disposal wells, operated by the East Texas Salt Water Disposal Company, are returning all produced water to the Woodbine producing reservoir. About 69 of the presently existing wells have not been subjected to U.S. Environmental Protection Agency Area-of-Review (AOR) requirements. A study has been carried out of opportunities for variance from AORs for these existing wells and for new wells that will be constructed in the future. The study has been based upon a variance methodology developed at the University of Missouri-Rolla under sponsorship of the American Petroleum Institute and in coordination with the Ground Water Protection Council. The principal technical objective of the study was to determine if reservoir pressure in the Woodbine producing reservoir is sufficiently low so that flow of salt-water from the Woodbine into the Carrizo-Wilcox ground water aquifer is precluded. The study has shown that the Woodbine reservoir is currently underpressured relative to the Carrizo-Wilcox and will remain so over the next 20 years. This information provides a logical basis for a variance for the field from performing AORs.

Meeting Name

Annual Technical Conference and Exhibition. Part Delta (1996: Oct. 6-9, Denver, CO)


Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Environmental protection; Groundwater flow; Oil well drilling; Saline water; Well pressure; Area of review (AOR) requirements; Oil fields

Geographic Coverage


Document Type

Article - Conference proceedings

Document Version


File Type





© 1996 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

01 Oct 1996