Current through Register Vol. 41, No. 3, September 23, 2024
A. Water protection string.
1. Except as provided in subdivision A 5 of
this section, the permittee shall set a water-protection string set to a point
at least 300 feet below the surface or 50 feet below the deepest known
groundwater horizon, whichever is deeper, circulated and cemented to the
surface. If cement does not return to the surface, every reasonable effort
shall be made to fill the annular space by introducing cement from the
surface.
2. The operator shall test
or require the cementing company to test the cement mixing water for pH and
temperature prior to mixing the cement and to record the results on the
cementing ticket.
3. After the
cement is placed, the operator shall wait a minimum of eight hours and allow
the cement to achieve a calculated compressive strength of 500 psi before
drilling, unless the director approves a shorter period of time. The
wait-on-cement time shall be recorded within the records kept at the drilling
rig while drilling is taking place.
4. When requested by the director, the
operator shall submit copies of cement tickets or other documents that indicate
the above specifications have been followed.
5. A coal-protection string may also serve as
a water protection string only for gob wells.
B. Coal protection strings.
1. When any well penetrates coal seams that
have not been mined out, the permittee shall, except as provided in
subdivisions B 2 and B 3 of this section, set a coal-protection string. The
coal-protection string shall exclude all fluids, oil, gas, and gas pressure,
except that which is naturally present in each coal seam. The coal-protection
string shall also exclude all injected material or disposed waste from the coal
seams or the wellbore. The string of casing shall be set to a point at least 50
feet below the lowest coal seam, or as provided in subdivision B 3 of this
section, and shall be circulated and cemented from that point to the surface,
or to a point not less than 50 feet into the water-protection string or strings
which are cemented to the surface.
2. For good cause shown, either before or
after the permit is issued, when the procedure specified in subdivision B 1 of
this section is demonstrated by the permittee as not practical, the director
may approve a casing program involving:
a.
The cementing of a coal-protection string in multiple stages;
b. The cementing of two or more
coal-protection strings; or
c. The
use of other alternative casing procedures.
3. The director may approve the program,
provided he is satisfied that the result will be operationally equivalent to
compliance with the provisions of subdivision B 1 of this section for the
purpose of permitting the subsequent safe mining through the well or otherwise
protecting the coal seams as required by this section. In the use of multiple
coal-protection strings, each string below the topmost string shall be cemented
at least 50 feet into the next higher string or strings that are cemented to
the surface and be verified by a cement top log.
4. Depth of coal-protection strings.
a. A coal-protection string shall be set to
the top of the red shales in any area underlain by them unless, on a showing by
the permittee in the permit application, the director has approved the casing
point of the coal-protection string at some depth less than the top of the red
shales. In such event, the permittee shall conduct a gamma-ray/density log
survey on an expanded scale to verify whether the well penetrates any coal seam
in the uncased interval between the bottom of the coal-protection string as
approved and the top of the red shales.
b. If an unanticipated coal seam or seams are
discovered in the uncased interval, the permittee shall report the discovery in
writing to the director. The permittee shall cement the next string of casing,
whether a part of the intermediate string or the production string, in the
applicable manner provided in this section for coal-protection strings, from a
point at least 50 feet below the lowest coal seam so discovered to a point at
least 50 feet above the highest coal seam so discovered.
c. The gamma-ray/density log survey shall be
filed with the director at the same time the driller's log is filed under
4VAC25-150-360.
d. When the director believes, after
reviewing documentation submitted by the permittee, that the total drilling in
any particular area has verified the deepest coal seam higher than the red
shales, so that further gamma-ray/density logs on an expanded scale are
superfluous for the area, he may waive the constructing of a coal-protection
string or the conducting of such surveys deeper than 100 feet below the
verified depth of the deepest coal seam.
C. Coal-protection strings of wells drilled
prior to July 1, 1982. In the case of wells drilled prior to July 1, 1982,
through coal seams without coal-protection strings as prescribed in subsection
B of this section, the permittee shall retain such coal-protection strings as
were set. During the life of the well, the permittee shall, consistent with a
plan approved by the director, keep the annular spaces between the various
strings of casing adjacent to coal seams open to the extent possible, and the
top ends of all such strings shall be provided with casing heads, or such other
approved devices as will permit the free passage of gas or oil and prevent
filling of the annular spaces with dirt or debris.
D. Producing from more than one stratum. The
casing program for any well designed or completed to produce from more than one
stratum shall be designed in accordance with the appropriate standard practices
of the industry.
E. Casing through
voids.
1. When a well is drilled through a
void, the hole shall be drilled at least 30 feet below the void. The annular
space shall be cemented from the base of the casing up to the void, and every
reasonable attempt shall be made to fill up the annular space from the top of
the void to the surface; or it shall be cemented at least 50 feet into the next
higher string or strings of casing that are cemented to the surface, and shall
be verified by a cement top log.
2.
For good cause shown, the director may approve alternate casing procedures
proposed by the permittee, provided that the director is satisfied that the
alternative casing procedures are operationally equivalent to the requirements
imposed by subdivision E 1 of this section.
3. For good cause shown, the director may
impose special requirements on the permittee to prevent communication between
two or more voids.
F. A
well penetrating a mine other than a coal mine. In the event that a permittee
has requested to drill a well in such a location that it would penetrate any
active mine other than a coal mine, the director shall approve the safety
precautions to be followed by the permittee prior to the commencement of
activity.
G. Production casing.
1. Unless otherwise granted in a variance
from the director:
a. For coalbed methane gas
wells with cased completions and cased/open hole completions, production casing
shall be set and cemented from the bottom of the casing to the surface or to a
point not less than 50 feet into the lowest coal-protection or water-protection
string or strings which are cemented to the surface.
b. For coalbed methane gas wells with open
hole completions, the base of the casing shall be set to not more than 100 feet
above the uppermost coalbed which is to be completed open hole. The casing
shall be cemented from the bottom of the casing to the surface or to a point
not less than 50 feet into the lowest coal-protection or water-protection
string or strings which are cemented to the surface.
2. A coal-protection string may also serve as
production casing.
H.
Reporting of lost circulation zones. The permittee shall report to the director
as soon as possible when an unanticipated void or groundwater horizon is
encountered that results in lost circulation during drilling. The permittee
shall take every necessary action to protect the lost circulation
zone.
Statutory Authority: §§ 45.1-161.3, 45.1-361.4,
and 45.1-361.27 of the Code of Virginia.
