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.