Salt Lake Oil Field
The Salt Lake Oil Field is an oil field underneath the city of
The adjacent and geologically related South Salt Lake Oil Field, not discovered until 1970, is still productive from an urban drillsite it shares with the nearby Beverly Hills Oil Field, also run by Plains Exploration and Production.[3]
Setting
The field is one of many in the Los Angeles Basin. Immediately to the west is the San Vicente Oil Field, and to the southwest the large Beverly Hills Oil Field. To the east are the Los Angeles City Oil Field and Los Angeles Downtown Oil Fields, the former one of the earliest to be drilled in the basin, and the one responsible along with the Salt Lake Field for the early twentieth-century oil boom in the area. Abutting the field to the southwest is the recently discovered and still active South Salt Lake Oil Field. The land above the two oil fields has a mean elevation of approximately 200 feet (61 m) above sea level, and slopes gently towards the south-southwest, away from the Santa Monica Mountains, draining via Ballona Creek towards Santa Monica Bay in the Pacific Ocean.[1]
The productive region of the field is approximately three miles long by one mile across, with the long axis west to east along and parallel to
The adjacent South Salt Lake Oil Field is much smaller than its northern neighbor. Discovered in 1970, and only about a mile long by a thousand feet across, this field is exploited entirely from an urban drillsite at Genesee Avenue and Pico Boulevard within the bounds of the Beverly Hills Oil Field. The only active operator is also Plains Exploration and Production; as of 2009, there were 16 active wells in the South Salt Lake field.[3]
Geology
The field is near the northern edge of the
A total of six producing horizons, lettered A through F from top to bottom, have been identified in the Salt Lake field. Only Pool "A", first to be discovered, is in the Repetto, having an average depth of only about 1,000 feet (300 m) below ground surface (bgs). Pools "B" and "C" were found by 1904, and the deeper pools "D", "E", and "F", ranging from 2,850 to 3,300 feet (1,000 m) bgs, were found in 1960 with the resumption of drilling from the Gilmore Drilling Island.[7] Oil from the field is heavy and sulfurous, with API gravity ranging from 9 to 22, but usually 14-18; sulfur content is high at 2.73% in each pool.[8]
In the South Salt Lake field, two pools have been identified, both in 1970: the Clifton Sands and the Dunsmuir Sands, at 1,000 feet (300 m) and 2,500 feet (760 m) depth respectively. Oil is found in several steeply dipping sand units bounded by impermeable rocks; the sands pinch out towards the ground surface, and oil accumulates in the upper portions.[9] The oil in this field is slightly less heavy than in the main Salt Lake field, with API gravity ranging from 22 to 26. Sulfur content was not reported.[10]
History, production, and operations
In the 1890s, dairy farmer Arthur F. Gilmore found oil on his land, probably in the vicinity of the La Brea Tar Pits. The field was named after the Salt Lake Oil Company, the first firm to arrive to drill in the area. The discovery well was spudded (started) in 1902.[11] Details of the discovery well – depth, exact location, production rate – are not known.[12]
Development of the field was fast, as oil wells spread across the landscape, with drillers hoping to match the production boom taking place a few miles to the east at the Los Angeles City field. Peak production was in 1908.[13] By 1912, there were 326 wells, 47 of which had already been abandoned,[14] and by 1917 more than 450, which had by then produced more than 50 million barrels of oil.[15] After this peak, production declined rapidly. Land values rose, corresponding to the fast growth of the adjacent city of Los Angeles, and the field was mostly idled in favor of housing and commercial development. The early wells were abandoned; many of their exact locations are not known, and are now covered with buildings and roads.
By the 1960s, new developments in
Operations at this drilling site, known as the "MacFarland Drilling Island" or the "Gilmore Drilling Island", continued until the 1990s.
With the shutting down of the Gilmore drilling island, royalty payments to many of the property owners of the land directly over the field ended. Some of them had been receiving monthly checks for as much as $2,500,[11] a situation similar to that at the Beverly Hills field.
Originally, Los Angeles planned to put a Metro subway line along Fairfax Avenue, but chose to reroute it because of the high levels of methane gas in the subsurface environment, since this flammable gas posed a safety risk.[17] It was only later that the oil field was recognized as the source of the methane gas. This hazard was realized spectacularly on the night of March 24, 1985, when a Ross clothing store filled with gas overnight and exploded, injuring 23 people.[1]
1985 Ross Dress for Less explosion
Seepage of
Since naturally occurring methane is odorless – utility companies add
1989 gas venting and evacuation
In 1989, a similar methane gas buildup occurred underneath 3rd Street and adjacent buildings, probably because of the accidental plugging of a gas-venting well built after the Ross incident.[21] Since the venting well had become clogged with a buildup of debris, methane slowly collected under the street and adjacent impermeable surfaces, bursting out on the morning of Tuesday, February 7, 1989, in a fountain of mud, water, and methane gas; no explosion occurred, since there was no source of ignition, and city emergency crews quickly cordoned off the area. To prevent similar incidents, Los Angeles further upgraded their City Building Code to require new buildings to have adequate venting systems, and be underlain with an impermeable membrane to prevent methane from getting in beneath the foundation.[17]
Notes
- ^ ISBN 0-89863-171-8.
- ^ a b Salt Lake Field query, California Department of Oil, Gas, and Geothermal Resources
- ^ a b South Salt Lake Field query, California Department of Oil, Gas, and Geothermal Resources
- ^ a b c Hamilton/Meehan, p. 152
- ^ a b Repetto Formation, at Bureau of Economic Geology, University of Texas, Austin Archived 2011-07-19 at the Wayback Machine
- ^ Hamilton/Meehan, p. 151
- ^ California Oil and Gas Fields, Volumes I, II and III. Vol. I (1998), Vol. II (1992), Vol. III (1982). California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR). 1,472 pp. Salt Lake information pp. 442-447. PDF file available on CD from www.consrv.ca.gov. (As of September 2009, not available for download on their FTP site.) p. 442-446
- ^ DOGGR, 443-444
- ^ DOGGR, p. 446
- ^ DOGGR, p. 447
- ^ a b c d Landsberg, Mitchell (August 6, 2001). "Decades-Old Oil Field Dies as Fairfax Area Mall Takes Shape". Los Angeles Times. Retrieved December 4, 2009.
- ^ DOGGR, p. 443
- ^ DOGGR, p. 444
- ^ Prutzman, Paul W. (1913). Petroleum in Southern California. Sacramento, California: California State Mining Bureau. p. 227.
- ^ Hamilton/Meehan, pp. 146-147
- ^ a b Hamilton/Meehan, p. 147
- ^ a b c Perera, Dave (May 10, 2001). "Fresh Produce and Streets of Fire: Making Sense of the Methane Explosion in the Fairfax". LA Weekly. Archived from the original on June 7, 2015. Retrieved December 4, 2009.
- ^ ISBN 0-07-027689-7.
- ^ Hamilton/Meehan, p. 154
- ISBN 0-88415-430-0.
- ^ Ramos, George; Stephen Braun (February 8, 1989). "Major Methane Gas Leak Closes Shopping Strip". Los Angeles Times. Retrieved December 4, 2009.
References
- California Oil and Gas Fields, Volumes I, II and III. Vol. I (1998), Vol. II (1992), Vol. III (1982). California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR). 1,472 pp. Salt Lake information pp. 442–447. PDF file available on CD from www.consrv.ca.gov. (As of September 2009, not available for download on their FTP site.)
- California Department of Conservation, Oil and Gas Statistics, Annual Report, December 31, 2006.
- California Department of Conservation, Oil and Gas Statistics, Annual Report, December 31, 2007.