There were no well failures associated with oil and gas well stimulation and treatment (WST), no emergency responses or spills, and no requests for confidential well status or trade secret protection from Jan. 1, 2014, through June 30, 2015, California’s Oil, Gas & Geothermal Division said in its first comprehensive WST report to the state legislature.
The agency, which is part of California’s Conservation Department, submitted the report to state legislators on Dec. 31, 2015, as required under SB 4, which Gov. Jerry Brown (D) signed into law in September 2013. The division had begun meeting with stakeholders to discuss drafting WST regulations in spring 2012, and continued to develop emergency regulations for the January 2014-June 2015 interim period once the bill became law.
During that period, it approved 2,127 WST permits (interim WST notices) for 15 operators for 365 days from each approval date. About 95% of the approved interim WST notices involved hydraulic fracturing, the agency said.
“With few exceptions, WSTs were limited geographically to Kern, Kings, and Ventura counties in relatively mature oil fields,” its initial report said. “Ninety-nine percent occurred in Kern County, 89% [were] performed on diatomite.” The average fracture length in diatomite WSTs was 83 ft while nondiatomite WST’s fracture length averages were in the 150-308 ft range, it indicated.
The report also said that:
• 98% of recovered WST fluids were reinjected into Class II underground injection wells, which are regulated separately under the division’s Underground Injection Control (UIC) program.
• 78% of the water used as base fluids in WST treatments came from domestic water systems, and 84% was reported as suitable for domestic or irrigation purposes.
• The division issued 58 violation notices for minor infractions of WST regulatory requirements during the 18-month period.
• Out of more than 1,000 neighbors receiving WST notices, only one requested water sampling.
• All WST operations except one were performed within existing oil field boundaries, and the one performed outside an existing boundary occurred after a groundwater monitoring plan was developed.
Contact Nick Snow at [email protected].