Current through Register Vol. 50, No. 9, September 20, 2024
A. The operator of the storage well and
cavern shall have the burden of meeting the requirements for well and cavern
mechanical integrity. The Office of Conservation shall be notified in writing
at least seven days before any scheduled mechanical integrity test. The test
may be witnessed by Office of Conservation personnel, but must be witnessed by
a qualified third party. Generally accepted industry methods and standards
shall apply when conducting and evaluating the tests required in this
Rule.
B. Frequency of Tests
1. Without exception or variance to these
rules and regulations, all Class V storage wells and caverns shall be tested
for and demonstrate mechanical integrity before beginning storage
activities.
2. All subsequent
mechanical integrity pressure tests shall occur at least once every five years.
Additionally, mechanical integrity testing shall be performed for the following
reasons regardless of test frequency:
a. after
physical alteration to any cemented casing or cemented liner;
b. after performing any remedial work to
reestablish well or cavern integrity;
c. before returning the cavern to storage
service after a period of salt solution-mining or washing to purposely increase
storage cavern size or capacity;
d.
before well closure, except when the cavern has experienced mechanical
failure;
e. whenever leakage into
or out of the cavern system is suspected;
f. whenever the commissioner determines a
test is warranted.
C. Test Method
1. All mechanical integrity pressure and leak
tests shall demonstrate no significant leak in the cavern, wellbore, casing
seat, and wellhead and the absence of significant fluid movement. Test
schedules and methods shall consider neighboring activities occurring at the
salt dome to reduce any influences those neighboring activities may have on the
cavern being tested.
2. When
practicable, tests shall be conducted using an approved interface method with
density interface and temperature logging using test materials having the same
or comparable leak off qualities as the stored product. An alternative test
method may be used if the alternative test can reliably demonstrate well/cavern
mechanical integrity and with prior written approval from the Office of
Conservation.
3. The cavern
pressure shall be stabilized before beginning the test. Pressure stabilization
shall be when the rate of cavern pressure change is no more than 10 PSIG during
24 hours.
4. The stabilized test
pressure to apply at the surface shall be calculated with respect to the depth
of the shallowest occurrence of either the cavern roof or deepest cemented
casing seat and shall not exceed a pressure gradient of 0.90 PSI per foot of
vertical depth. However, the well or cavern shall never be subjected to
pressures that exceed the storage well's maximum allowable operating pressure
or exceed the rated burst or collapse pressure of all well tubulars (cemented
or hanging strings) even for short periods during testing.
5. A mechanical integrity pressure and leak
test shall be run for at least 24 hours after cavern pressure stabilization and
must be of sufficient time duration to ensure a sensitive test. All pressures
shall be monitored and recorded continuously throughout the test. Continuous
pressure recordings may be achieved through mechanical charts or recorded
digitally. Mechanical charts shall not exceed a clock period of 24-hour
duration. The chart shall be scaled such that the test pressure is 30 percent
to 70 percent of full scale. All charts shall be selected such that its scaling
is of sufficient sensitivity to record all fluctuations of pressure,
temperature, or any other monitored parameter.
6. The commissioner may require that a
separate casing pressure test be included as part of the routine MIT.
7. Inactive caverns. The commissioner may
approve hydrostatic brine pressure monitoring for inactive wells and caverns
that are in pre-closure monitoring and will not be returned to service. For any
cavern removed from preclosure monitoring that has been subject to hydrostatic
brine pressure testing, a MIT must be performed in accordance with
§3727.C 1-6 above
prior to resuming any injection activities.
D. Submission of Pressure and Leak Test
Results. Submit one complete copy of the mechanical integrity pressure and leak
test results to the Office of Conservation within 60 days after test
completion. The report shall include the following minimum information:
1. current well and cavern completion
data;
2. description of the test
procedure including pretest preparation and the test method used;
3. one paper copy and an electronic version
of all wireline logs performed during testing;
4. tabulation of measurements for pressure,
volume, temperature, etc.;
5.
interpreted test results showing all calculations including error analysis and
calculated leak rates; and
6. any
information the owner or operator of the cavern determines is relevant to
explain the test procedure or results.
E. Mechanical Integrity Test Failure
1. Without exception or variance to these
rules and regulations, a storage well or cavern that fails a test for
mechanical integrity shall be immediately taken out of service. The failure
shall be reported to the Office of Conservation according to the notification
requirements of
§3709.I.8 The owner or
operator shall investigate the reason for the failure and shall take
appropriate steps to return the storage well or cavern to a full state of
mechanical integrity. A storage well or cavern is considered to have failed a
test for mechanical integrity for the following reasons:
a. failure to maintain a change in test
pressure of no more than 10 PSIG over a 24-hour period;
b. not maintaining interface levels according
to standards applied in the cavern storage industry; or
c. stored or test materials are determined to
have escaped from the storage well or cavern during storage
operations.
2. Written
procedures to rehabilitate the storage well or cavern, extended cavern
monitoring, or abandonment (closure and post-closure) of the storage well or
cavern shall be submitted to the Office of Conservation within 60 days of
mechanical integrity test failure.
3. If a storage well or cavern fails to
demonstrate mechanical integrity and where mechanical integrity cannot be
reestablished, the Office of Conservation may require the owner or operator to
begin closure of the well or cavern according to an approved closure and
post-closure plan.
a. The Office of
Conservation may waive implementation of closure requirements if the owner or
operator is engaged in a cavern remediation study and implements an interim
cavern monitoring plan. The owner or operator must seek written approval from
the Office of Conservation before implementing a salt cavern monitoring
program. The basis for the Office of Conservation's approval shall be that any
waiver granted shall not endanger the environment, or the health, safety, and
welfare of the public. The Office of Conservation may establish a time schedule
for salt cavern rehabilitation, cessation of interim cavern monitoring, and
eventual cavern closure and post-closure activities.
AUTHORITY
NOTE: Promulgated in accordance with
R.S.
30:4 et seq. and
R.S.
30:23 et seq.