Abstract: Reclamation of Saltwater-Contaminated Soil in the Big Lake Field
Michael L. Weathers, Kenneth R. Moore, Donald L. Ford, Charles K. Curlee
Since the discovery of the 1 Santa Rita well in 1923, millions of barrels of saltwater have been produced along with 135 million bbl of oil from the Big Lake field in Reagan County, Texas. Until the early 1960s, the accepted disposal method for the produced water was surface discharge to large evaporation ponds north of the field. Produced water was allowed to flow from wells to the ponds via natural topographic drainage. This practice resulted in 7000 ac of eroded, barren landscape characterized by highly saline soils incapable of supporting vegetation.
In 1989, the University of Texas System, the U.S.D.A. Soil Conservation Service, and Marathon Oil Company, which acquired Big Lake field in 1962, initiated an experimental project to reclaim the affected land and restore it to rangeland productivity. An underground drainage system, consisting of 125,000 ft of buried drainage conduit and eight collection sumps, was installed over nearly 300 ac of the affected area. Earthen terraces were constructed to capture and hold rainwater to aid downward percolation and leaching of salts from the soil profile. Salts leached from the soil are captured by the drainage system and pumped to injection wells for disposal.
The excellent revegetation that has occurred over the test area after three years of operations is encouraging and has shown the need for expanding and enhancing the existing system with supplemental water from freshwater wells, application of soil-amending agents, additional terracing, and selective planting of salt-tolerant species.
AAPG Search and Discovery Article #90983©1994 GCAGS and Gulf Coast SEPM 44th Annual Meeting, Austin, Texas, October 6-7, 1994