Current through Register Vol. 50, No. 9, September 20, 2024
A. The operator of
the solution-mining 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 solution-mining wells and caverns shall be tested
for and satisfactorily demonstrate mechanical integrity before beginning
injection activities.
2. All
subsequent demonstrations of mechanical integrity shall occur at least once
every five years. Additionally, mechanical integrity testing shall be done 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 well closure, except when the
cavern has experienced mechanical failure;
d. whenever leakage into or out of the cavern
system is suspected;
e. 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. Tests shall
be conducted using the nitrogen-brine interface method with density interface
and temperature logging. 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. Stabilization shall be reached 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
solution-mining 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 may be
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. Any MIT performed on a solution-mining
cavern shall include a separate pressure test on the casing of at least 60
minutes.
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
§3327.C 1-6 above
prior to resuming any injection activities.
D. Submission of Pressure and Leak Test
Results. One complete electronic copy of the mechanical integrity pressure and
leak test results, certified by a Louisiana licensed P.E. (See
§3303.G 3), shall be
submitted to the Office of Conservation within 60 days of 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 solution-mining 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
§3309. I.8 The owner
or operator shall investigate the reason for the failure and shall take
appropriate steps to return the solution-mining well or cavern to a full state
of mechanical integrity. A solution-mining 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 nitrogen-brine interface
levels according to standards applied in the solution-mining industry;
or
c. fluids are determined to have
escaped from the solution-mining well or cavern during solution-mining
operations.
2. Written
procedures for rehabilitation of the solution-mining well or cavern, extended
cavern monitoring, or abandonment (closure and post-closure) of the
solution-mining well or cavern shall be submitted to the Office of Conservation
within 60 days of mechanical integrity test failure.
3. Upon reestablishment of mechanical
integrity of the solution-mining well or cavern and before returning either to
service, a new mechanical integrity pressure and leak test shall be performed
that demonstrates mechanical integrity of the solution-mining well or cavern.
The owner or operator shall submit the new test results to the Office of
Conservation for written approval before resuming injection
operations.
4. If a solution-mining
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 within six months
according to an approved closure and post-closure plan.
5. If a cavern fails mechanical integrity and
where rehabilitation cannot be accomplished within six months, the Office of
Conservation may waive the six-month closure requirement 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.