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:

 

If multiple coal protective or water protective strings are run in a single wellbore and circulation is lost on any one of these strings, is it necessary to install at least one additional casing string needed if the operator intends to produce gas?

 

 

Response:

 

Any lost circulation zones encountered during the cementing of any water or coal protective casing string which prevent surface returns necessitate the installation of at least one additional casing string unless only oil will be produced at the well location and the annulus between the tubing and the surface casing is vented.  It should be noted that the coal protective strings installed in areas where the coal seam has been mined have a specific installation protocol described under Section 78.83(h).  This protocol is intended to minimize the potential for lost circulation.