A study commissioned by Plains Exploration & Production Co. concluded that hydraulic fracturing of two test wells in Inglewood oil field in Los Angeles County, Calif., indicated no detectable evidence that it might induce earthquakes or have negative impact on groundwater quality, a consultant reported. Carno Entrix of Los Angeles conducted the study, and the California Department of Conservation (DOC) posted the study on its web site.
California is expected to release a draft of fracing rules. Don Drysdale, spokesman with the DOC, told OGJ that it will be "several weeks" before a draft is issued.
The 1,200-acre Inglewood field is one of the largest contiguous urban oil fields in the US. It's adjacent to the communities of Baldwin Hills, View Park, Windsor Hills, Blair Hills, Ladera Heights, and Culver City.
The oil-producing zones in Inglewood field range 900-10,000 ft underground. A total of 1,475 wells have been drilled during the field's life with 469 wells in active production and 168 waterflood injection wells actively operating.
The fracing study was part of a 2011 settlement stemming from a lawsuit filed in 2008 against Los Angeles County and Plains E&P concerning land use. Standard Oil discovered Inglewood field near Culver City in 1924. Plains E&P has operated the field since December 2002. Conventional fracing has been done at the field.
Plains E&P conducted two high-volume frac jobs at separate wells for the purposes of the study. A frac completion was done in September 2011 at the VIC1-330 well and another frac completion was done in January 2012 at the VIC1-635 well. Halliburton Energy Services did the frac jobs, both in Nodular shale, a subunit of the Monterey shale. Microseismic monitoring and fracture mapping was done by Schlumberger Ltd. and by Halliburton Co.-owned Pinnacle.
Only one stage was completed during each operation, the study said. Both wells are vertical wells although fracing might be done in the future using horizontal wells.
Plains E&P also completed high-rate gravel pack jobs at two different wells early this year to collect information for the study. Both operations were conducted in the Vickers and Rindge formations by Halliburton.
Producing formations are Investment, Vickers, Rindge, Rubel, Upper and Lower Moynier, Bradna, Nodular shale, and Sentous (Inglewood field reservoirs map, OGJ, Apr. 19, 2004, p. 37).
"Tests conducted before, during, and after the use of hydraulic fracturing and high-rate gravel packing showed no effects on the integrity of the steel and cement casings that enclose oil wells," the study said. "There is also an ongoing program of well integrity tests at Inglewood oil field."
Noise and vibration associated with fracing tests at Inglewood field were within limits established by the Baldwin Hills Community Standards District, and emissions were within standards set by the regional air quality regulations of the South Coast Air Quality Management District.
The Los Angeles County Department of Public Health reported a community health assessment found no statistical difference of the health of the community compared with Los Angeles County overall. "The long history of oil production in the area provides operators with an excellent understanding of the local subsurface conditions and reduces standard risks and uncertainties that would be present in new operations," the report said.
