Allowable pillar to diameter ratio for strategic petroleum reserve caverns.

Technical Report · Sun May 01 04:00:00 EDT 2011

DOI:https://doi.org/10.2172/1013228· OSTI ID:1013228

Ehgartner, Brian L; Park, Byoung Yoon

This report compiles 3-D finite element analyses performed to evaluate the stability of Strategic Petroleum Reserve (SPR) caverns over multiple leach cycles. When oil is withdrawn from a cavern in salt using freshwater, the cavern enlarges. As a result, the pillar separating caverns in the SPR fields is reduced over time due to usage of the reserve. The enlarged cavern diameters and smaller pillars reduce underground stability. Advances in geomechanics modeling enable the allowable pillar to diameter ratio (P/D) to be defined. Prior to such modeling capabilities, the allowable P/D was established as 1.78 based on some very limited experience in other cavern fields. While appropriate for 1980, the ratio conservatively limits the allowable number of oil drawdowns and hence limits the overall utility and life of the SPR cavern field. Analyses from all four cavern fields are evaluated along with operating experience gained over the past 30 years to define a new P/D for the reserve. A new ratio of 1.0 is recommended. This ratio is applicable only to existing SPR caverns.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1013228
• Report Number(s): SAND2011-2896
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
SIMULATION
STABILITY
STRATEGIC PETROLEUM RESERVE