February 11, 2013
6:00 - 7:30 pm
State Technical Community College
10915 Hardin Valley Road, Knoxville
J.L Goins Administration Building, Cafeteria Annex
The Disaster at Jefferson Island
Human induced collapse and subsequent flooding of the
Jefferson Island, Louisiana salt mine.
Lessons for future underground storage and disposal.
R. C. (Dick) Merrill
Petroleum Consultant and Aviation Archeologist
One of the unique features of
Gulf Coast geology is the many salt domes that are common both in
the onshore portions of Texas and Louisiana as well as under the
Gulf of Mexico out and beyond the continental slope. These domes
form due to the rapid and heavy loading of Tertiary sediments,
onto the lower density, Jurassic Louann salt. Salt domes have
been exploited for the hydrocarbons trapped around their
periphery since the early 20th century. However they have been
mined for salt, sulfur and other minerals since the Civil war.
Starting in the second half of the 20th century salt domes have
been increasing used for storage of hydrocarbons and various
industrial wastes including radioactive waste. Several of these
storage, mining and disposal operations have resulted in collapse
of the overlying surface.
The Jefferson Island salt dome, located 9 miles west of New Iberia, Louisiana lies under Lake Peignoir. Lake Peignoir covers 1,100 acres with an average depth of 3 feet. The lake was formed by subsidence of the coastal marsh over the Jefferson Island salt dome. The salt dome contained an extensive multi-level salt mine operated by the Diamond Salt Company. The dome is also ringed by oil and gas accumulations.
On the morning of November 20, 1980, at about 6:00 AM, a Texaco operated drilling rig, drilling from a barge located in the middle of Lake Peignoir found the drill pipe stuck and the crew encountered other drilling anomalies. The drilling barge, which was sitting on the lake bottom, began to shift and the drilling crew abandoned the rig. At about the same time, miners working in the salt mine under the lake saw water pouring into the mine. Within hours the entire lake had drained, like a giant bathtub, into the mine along with several thousand cubic yards of Lake Bottom sediment forming a crater or sinkhole of about 160 acres and over 100 feet deep. As the water rushed into this sinkhole it swept away the drilling rig, a tug boat, 10 barges, a house trailer and about 70 acres of adjoining land. Amazingly, no lives were lost.
A non-published video will be shown at the presentation but to peak your interest, visit: http://flyingcuttlefish.wordpress.com/2012/08/19/1986-sinkhole-disaster/.
Page updated May 26, 2018