Regulatory Citation(s):
78.85. Cementing
standards.
(b) After the casing cement is place behind
surface casing, the operator shall permit the cement to set to a minimum
designed compressive strength of 350 pounds per square inch (psi) at the casing
seat. The cement placed at the bottom
300 feet of the surface casing must constitute a zone of critical cement and
achieve a 72-hour compressive strength of 1,200 psi and the free water
separation may be no more than 6 milliliters per 250 milliliters of cement. If the surface casing is less than 300 feet,
the entire cemented string constitutes a zone of critical cement.
Question:
Regulations are finalized while the operator
is finishing drilling the surface hole with a tophole
rig and a service company will be cementing the surface casing soon. Materials
have been ordered and the service company contract is in place. New cement standards require a zone of
critical cement which may require new materials, cement vendor testing,
etc. Although it is relatively easy in
many circumstances to quickly have the service company change/reformulate the
cement blend, depending on timing and how soon the surface casing is to be
cemented, there may be situations where it might not be practical to comply
with the new regulations.
Response:
Reasonable accommodation to allow cement as
prescribed under the old regulations is permissible. However, the new
regulations requiring cement returns to the surface or notice to the Department
in the event that surface returns are not achieved are still required.