NAC534A.260. Requirements for casing.

     1. All wells must be cased in such a manner as to minimize damage to the environment, ground and surface waters, geothermal resources and property.

     2. Except as otherwise ordered by the Administrator, the completion equipment for a well must be attached to the surface casing. All casing, except conductor casing, which reaches the surface must provide adequate anchorage for equipment for the prevention of a blowout and control of the pressure in the well.

     3. Surface casing must provide for control of formation fluids and protection of fresh water. The cement for the surface casing must be circulated up the annulus to the surface. If the cement does not circulate or falls back, the casing must be cemented at the surface. Sufficient casing must be set to reach a depth below all known or reasonably estimated levels of fresh water to protect those aquifers and to prevent blowouts or uncontrolled flows. Surface casing may not be set less than 10 percent of the proposed total depth of the well or a minimum of 50 feet, whichever is greater.

     4. When intermediate casing is installed, cement must be circulated to the surface or to the top of the casing with at least a 100-foot overlap into the next string of casing.

     5. Production casing may be set above or through the production or injection zone. Casing must be cemented to the surface or, if a liner is used, to the top of the casing. If surface casing overlaps into an intermediate string, the overlap must be at least 100 feet, solidly cemented and tested to withstand at least 750 pounds of pressure per square inch of gauge. A decline in the pressure of 10 percent or less in 30 minutes is acceptable. For domestic or commercial wells less pressure or another acceptable mechanical test may be approved by the Administrator.

     (Added to NAC by Comm’n on Mineral Resources, eff. 11-12-85)