Salt Caverns for Oil Field Waste Disposal: DOE Initiatives

1. DOE Program for Studying the Use of Salt Caverns for Oil Field Waste Disposal John Ford National Petroleum Technology Office

2. Early Efforts • in 1995, at the request of the Railroad Commission of Texas, NPTO funded Argonne National Laboratory to investigate the technical feasibility and legality of disposing oil field wastes in salt caverns • found that cavern disposal was feasible • several caverns were already in use in Texas, Canada, and Europe • there were no legal prohibitions against cavern disposal • States may need to revise their regulations

3. Early Efforts - continued • the greatest environmental and health risk occurred following closure of caverns • more research was needed • DOE recommended that 4 research organizations join forces to form the Salt Cavern Research Partnership • Argonne National Laboratory • Sandia National Laboratories • Texas Bureau of Economic Geology • Solution Mining Research Institute

4. Other Baseline Studies • Argonne conducted two other studies to complete a baseline of information on cavern disposal • cost study • found that caverns could compete economically with other types of oil field waste disposal facilities in the same geographic area • risk study • found that the risks associated with various types of cavern failure scenarios were all below the EPA’s acceptable risk threshold

5. NORM Study • Argonne’s initial cavern studies looked at oil field wastes other than NORM • NPTO funded another study to evaluate NORM disposal in caverns • the same conclusions as mentioned above apply to NORM • Since then, the Railroad Commission has approved permits for at least two caverns to dispose of NORM waste

6. Salt Cavern Modeling Efforts • Sandia completed modeling investigations about the behavior of horizontal caverns formed in salt structures • identified potential sites for horizontal caverns • evaluated roof stability • calculated leaching times for different sized caverns

7. Salt Formation Investigation • the Bureau of Economic Geology evaluated and mapped the bedded salt formations in the Permian Basin • salt thickness • depth to top of salt • salt dissolution

8. Research on Post-Closure Behavior • Solution Mining Research Institute oversaw preparation of a bibliography for cavern behavior following plugging and abandonment • salt creep and rock strength behavior • permeability of rock salt • temperature and pressure • plugging and sealing

9. Public Education and Outreach • Salt Cavern Research Partnership Advisory Committee recommended that DOE fund a public education effort to provide information to both a wider audience and to nontechnical audiences • Argonne produced a brochure for nontechnical audiences and the Salt Cavern Information Website • all NPTO-funded cavern reports can be downloaded www.npto.doe.gov/saltcaverns