Assumption Parish has recently had to evacuate residents near a huge sink hole that geologists believe is related to the collapse of a salt dome being used by industry to store products. The Richton Salt Dome has been considered for the National Petroleum Reserve program. Here is an abstract from a recent scientific report:
“The design of caverns in salt must consider the unique mechanical behavior of the salt compared to that of other geologic media. For example, salt is known to creep (time-dependent deformation) when subjected to shear stress and elevated temperature. As a result, caverns may close over time, particularly at low cavern fluid pressures, thereby reducing the volume available for storage. In addition, salt is also known to dilate (volume expansion) through a process of stress-induced microfracturing that creates new porosity. Microfracturing may also cause localized spalling of salt slabs from the cavern roof and walls (Munson et al, 2003) which could lead to damage of the hanging strings that provide access to the stored oil and ultimately to disruption of operations…
The salt was previously tested as part of the Office of Nuclear Waste Isolation (ONWI) program in the early/mid-1980’s that evaluated the dome as a potential candidate for high level nuclear waste storage.”
Revised results for geomechanical testing of MRIG-9 core for the potential SPR siting at the Richton Salt Dome.
Author: Scott Thomas Broome; Sandia National Laboratories; Stephen J Bauer
Publisher: United States 2010 Feb 01