Prior to drilling out the plug after cementing, all blank casing strings, except the conductor casing, shall be pressure tested as shown in the table below. Loss in pressure shall not exceed 10 percent during a 30 minute test; corrective measures must be taken until a satisfactory test is obtained.

After cementing any of the above strings, drilling shall not be commenced until a time lapse of: eight hours for the first surface casing string and 12 hours for all other casing strings, or sufficient time for the bottom 500 feet of annular cement fill to attain a compressive strength of at least 500 psi based on a pretest of the slurry at the temperature and pressure at the cementing depth, using testing procedures as set forth by the American Petroleum Institute in RP 10B, 1972, incorporated here by reference.

All casing pressure tests shall be witnessed and approved by a Division inspector prior to drilling out of the casing or perforating opposite possible oil or gas zones. Inspection of data recorded by a device approved by the Division may be substituted for witnessing.