Regulatory Citation(s): 

 

78.83b. Casing and cementing – lost circulation.

 

(a) If cement used to permanently cement the surface or coal protective casing is not circulated to the surface despite pumping a volume of cement equal to or greater than 120% of the calculated annular space, the operator shall determine the top of the cement, notify the Department, and meet one of the following requirements as approved by the Department.

 

 

Question:

 

Section 78.83b.(a)(1) – (4) provides four specific casing options in the event that lost circulation is encountered over the surface casing interval.  Are operators allowed to select one method preliminarily but change to another method later?  Can subtle variations of these methods be implemented if deemed acceptable by the appropriate Regional contact and how should these procedures be documented?

 

 

Response:

 

Operators have the flexibility to deviate from their initial plan and select from any of the other available options under the referenced section of the regulations provided the rationale for doing so is deemed acceptable and the selected method does not introduce any environmental or well integrity concerns associated with the lost circulation zone or other site-specific conditions.  The change in methods and Department approval should be documented in all cases. 

 

Other reasonable and technically sound methods for addressing lost circulation may also be implemented even if they vary from Section 78.83b.(a)(1) – (4).  However, they must be approved by the appropriate Regional staff prior to implementation and should be documented using the methods available under Section 78.75 either prior to or after execution of the alternate casing and cementing procedure.