Fossil Fuels Petroleum

Summary of Degas II performance at the US Strategic Petroleum Reserve Big Hill site.

Authors: Rudeen, David K. (GRAM, Inc., Albuquerque, NM) Lord, David L.
 
Abstract: Crude oil stored at the US Strategic Petroleum Reserve (SPR) requires mitigation procedures to maintain oil vapor pressure within program delivery standards. Crude oil degasification is one effective method for lowering crude oil vapor pressure, and was implemented at the Big Hill SPR site from 2004-2006. Performance monitoring during and after degasification revealed a range of outcomes for caverns that had similar inventory and geometry. This report analyzed data from SPR degasification and developed a simple degas mixing (SDM) model to assist in the analysis. Cavern-scale oil mixing during degassing and existing oil heterogeneity in the caverns were identified as likely causes for the range of behaviors seen. Apparent cavern mixing patterns ranged from near complete mixing to near plug flow, with more mixing leading to less efficient degassing due to degassed oil re-entering the plant before 100% of the cavern oil volume was processed. The report suggests that the new cavern bubble point and vapor pressure regain rate after degassing be based on direct in-cavern measurements after degassing as opposed to using the plant outlet stream properties as a starting point, which understates starting bubble point and overstates vapor pressure regain. Several means to estimate the cavern bubble point after degas in the absence of direct measurement are presented and discussed.
Publication Date: 01 Oct 2007
Report numbers: SAND2007-5564
DOE Contract number: AC04-94AL85000
Resource Type: Technical Report
Research Organizations: Sandia National Laboratories
Sponsoring Organizations: USDOE
Country of Publication: United States
Language: English
Keywords relating to this report:
BUBBLES
DEGASSING
GEOMETRY
MITIGATION
MONITORING
PERFORMANCE
PETROLEUM
STRATEGIC PETROLEUM RESERVE
VAPOR PRESSURE
Related subjects:
DEGASSING.
STRATEGIC PETROLEUM RESERVE
STRATEGIC PETROLEUM RESERVE.
UNITED STATES
VAPOR PRESSURE.