California Code of Regulations
Title 14 - Natural Resources
Division 2 - Department of Conservation
Chapter 4 - Development, Regulation, and Conservation of Oil and Gas Resources
Subchapter 4 - State-Wide Geothermal Regulations
Article 3 - Drilling
Section 1935.2 - Surface Casing
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
Surface casing shall provide for control of formation fluids, for protection of shallow usable groundwater, and for adequate anchorage for blowout prevention equipment. All surface casing shall be cemented with sufficient cement to fill the annular space from the shoe to the surface. The following requirements may be modified or waived by the Division for low-temperature geothermal wells.
(a) Length of Surface Casing.
(b) Cementing Point for Surface Casing.
Surface casing shall be cemented through a sufficient series of low permeability, competent lithologic units (such as claystone or siltstone) to ensure a solid anchor for blowout prevention equipment and to protect usable groundwater and surface water from contamination. A second string of surface casing may be required if the first string has not been cemented through a sufficient series of low permeability, competent lithologic units, and either a rapidly increasing thermal gradient or rapidly increasing formation pressures are encountered.
(c) Drilling Fluid Return Temperatures. The temperature of the return drilling fluid shall be monitored continuously during the drilling of the surface casing hole. Either a continuous temperature monitoring device shall be installed and maintained in working condition, or the temperature shall be read manually. In either case, return drilling fluid temperatures shall be entered into the log book after each joint of pipe has been drilled down (every 10 meters, about 30 feet).
1. Amendment filed 8-16-79; effective thirtieth day thereafter (Register 79, No. 33).
2. Change without regulatory effect amending first paragraph and subsections (a)(2)-(3) filed 12-26-2006 pursuant to section 100, title 1, California Code of Regulations (Register 2006, No. 52).
Note: Authority cited: Section 3714, Public Resources Code. Reference: Sections 3739 and 3740, Public Resources Code.