La. Admin. Code tit. 43 § XVII-3327

Current through Register Vol. 50, No. 9, September 20, 2024

Section XVII-3327 - Well and Cavern Mechanical Integrity Pressure and Leak Tests

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.

La. Admin. Code tit. 43, § XVII-3327

Promulgated by the Department of Natural Resources, Office of Conservation, LR 40:337 (February 2014), Amended LR 42418 (3/1/2016), Amended LR 482313 (9/1/2022).

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:4 et seq.