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 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 in to the
surface. If the cement does not return to the surface, every reasonable attempt
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 (WOC) 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.
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 and 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 is
demonstrated by the permittee as not practical, the director may approve a
casing program involving the cementing of a coal-protection string in multiple
stages, or the cementing of two or more coal-protection strings, or the use of
other alternative casing procedures. 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 of 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.
3. 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 substantially 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 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 be
verified by a cement top log.
2.
For good cause shown, the director may approve alternative 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. 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 and 45.1-361.27 of the Code of
Virginia.
