Current through Register Vol. 50, No. 9, September 20, 2024
A.
Applicability. This Section applies to all applicants, owners, or operators of
Class V storage wells and caverns. The applicant, owner, or operator shall be
responsible for showing that the storage operation shall be accomplished using
good engineering and geologic practices for storage operations to preserve the
integrity of the salt stock and overlying sediments. In addition to all
applicants showing this in their application, as part of the compliance review
found in §3709 K, the
commissioner may require any owner or operator of a storage well to provide the
same or similar information required in this Section. This shall include, but
not be limited to:
1. an assessment of the
engineering, geological, geomechanical, geochemical, geophysical properties of
the salt stock;
2. stability of
salt stock and overlying and surrounding sediments;
3. stability of the cavern design
(particularly regarding its size, shape, depth, and operating
parameters);
4. the amount of
separation between the cavern of interest and adjacent caverns and structures
within the salt stock; and
5. the
amount of separation between the outermost cavern wall and the periphery of the
salt stock;
6. an assessment of
well information and oil and gas activity within the vicinity of the salt dome
which may affect the storage cavern.
B. Geological Studies and Evaluations. The
applicant, owner, or operator shall do a thorough geological, geophysical,
geomechanical, and geochemical evaluation of the salt stock to determine its
suitability for Class V storage, stability of the cavern under the proposed set
of operating conditions, and where applicable, the structural integrity of the
salt stock between an adjacent cavern and salt periphery under the proposed set
of operating conditions. A listing of data or information used to characterize
the structure and geometry of the salt stock shall be included.
1. Where applicable, the evaluation shall
include, but should not be limited to:
a.
geologic mapping of the structure of the salt stock and any cap rock;
b. geologic history of salt
movement;
c. an assessment of the
impact of possible anomalous zones (salt spines, shear planes, etc.) on the
storage well or cavern;
d.
deformation of the cap rock and strata overlying the salt stock;
e. investigation of the upper salt surface
and adjacent areas involved with salt dissolution;
f. cap rock formation and any non-vertical
salt movement.
2. The
applicant shall perform a thorough hydrogeologic study on strata overlying the
salt stock to determine the occurrence of the lowermost underground source of
drinking water immediately above and near the salt stock.
3. The applicant shall investigate regional
and local tectonic activity and the potential impact (including ground
subsidence) of the project on surface and subsurface resources.
4. The proximity of all existing and proposed
storage caverns to the periphery of the salt stock and to manmade structures
within the salt stock shall be demonstrated to the Office of Conservation at
least once every five years (see
§3709.K) by providing
the following:
a. an updated structure
contour map of the salt stock. The updated map should make use of all available
data. The horizontal configuration of the salt cavern should be shown on the
structure map and reflect the caverns' maximum lateral extent as determined by
the most recent sonar caliper survey; and
b. vertical cross-sections of the salt
caverns showing their outline and position within the salt
stock.
C. Core
Sampling
1. Each newly permitted well shall
be cored at intervals approved by the commissioner, but at a minimum, coring
shall include the shoe of the deepest casing set into the salt, the proposed
cavern roof, and the midpoint of the proposed cavern, unless exempted by the
commissioner. The cavern shall be or shall have been cored over sufficient
depth intervals to yield representative samples of the subsurface geologic
environment. This shall include coring of the salt stock and may include coring
of overlying formations, including any cap rock. Cores should be obtained using
the whole core method. Core acquisition, core handling, and core preservation
shall be done according to standard field sampling practices considered
acceptable for laboratory tests of recovered cores.
2. Data from previous coring projects that
meet modern analytical industry standards may be used instead of actual core
sampling provided the data is specific to the salt dome of interest. It shall
be the responsibility of the applicant to make a satisfactory demonstration
that data are applicable to the salt dome and cavern location(s) of
interest.
D. Core
Analyses and Laboratory Tests. Analyses and tests shall consider the
characteristics of the injected materials and should provide data on the salt's
geomechanical, geophysical, geochemical, mineralogical properties, x-ray
diffraction analysis, microstructure, and where necessary, potential for
adjacent cavern connectivity, with emphasis on cavern shape and the operating
conditions. All laboratory tests, experimentation, and numeric modeling shall
be conducted using methods that simulate the proposed operating conditions of
the cavern. Test methods shall be selected to define the deformation and
strength properties and characteristics of the salt stock under cavern
operating conditions. Test results, analyses, and operating recommendations
shall be summarized in an interpretive report.
E. Area of Review. A thorough evaluation
shall be undertaken of both surface and subsurface activities in the defined
area of review of the individual storage well or project area (area permit)
that may influence the integrity of the salt stock, storage well, and cavern,
or contribute to the movement of injected fluids outside the cavern, wellbore,
or salt stock.
1. Surface Delineation
a. The area of review for individual storage
wells shall be a fixed radius around the wellbore of not less than 1320
feet.
b. The area of review for
wells in a storage project area (area permit), shall be the project area plus a
circumscribing area the width of which is not less than 1320 feet. The area of
review for new storage wells within an existing area permit shall be the
project area plus a circumscribing area the width of which is not less than
1320 feet. Only information outlined in
§3713.E 2, not
previously assessed as part of the area permit application review or as part of
the review of an application for a subsequent storage well located within the
approved area permit, shall be considered.
c. Exception shall be noted as in
§3713.E.2.c and d
below.
2. Subsurface
Delineation. At a minimum, the following shall be identified within the area of
review:
a. all known active, inactive, and
abandoned wells within the area of review with known depth of penetration into
the cap rock or salt stock;
b. all
known water wells within the area of review;
c. all salt caverns within the salt stock
regardless of use, depth of penetration, or distance to the proposed storage
well or cavern;
d. all conventional
(dry or room and pillar) mining activity either active or abandoned occurring
anywhere within the salt stock regardless of distance to the proposed Class V
storage well or cavern;
e. all
producing formations either active or depleted.
3. Water Samples. A representative number of
water wells identified under
§3713.E.2.b shall be
sampled and analyzed by an accredited laboratory for chloride and total
dissolved solids.
F.
Corrective Action
1. For manmade structures
identified in the area of review that penetrate the salt stock and are not
properly constructed, completed, or plugged and abandoned, the applicant shall
submit a corrective action plan consisting of such steps, procedures, or
modifications as are necessary to prevent the movement of fluids outside the
cavern or into underground sources of drinking water.
a. Where the plan is adequate, the provisions
of the corrective action plan shall be incorporated into the permit as a
condition.
b. Where the plan is
inadequate, the Office of Conservation shall require the applicant to revise
the plan, or prescribe a plan for corrective action as a condition of the
permit, or the application shall be denied.
2. Any permit issued for an existing storage
well for which corrective action is required shall include a schedule of
compliance for complete fulfillment of the approved corrective action
procedures. If the required corrective action is not completed as prescribed in
the schedule of compliance, the permit shall be suspended, modified, revoked
and reissued, or terminated according to these rules and regulations.
3. No permit to inject shall be issued for a
new storage well or repermitted storage well until all required corrective
action obligations have been fulfilled.
4. The commissioner may require as a permit
condition that injection pressure be so limited that pressure in the injection
zone does not cause the movement of fluids into a underground source of
drinking water through any improperly completed or abandoned well within the
area of review. This pressure limitation shall satisfy the corrective action
requirement. Alternatively, such injection pressure limitation can be part of a
compliance schedule and last until all other corrective action has been
taken.
5. When setting corrective
action requirements for storage wells, the commissioner shall consider the
overall effect of the project on the hydraulic gradient in potentially affected
underground sources of drinking water, and the corresponding changes in
potentiometric surface(s) and flow direction(s) rather than the discrete effect
of each well. If a decision is made the corrective action is not necessary, the
monitoring program required in
§3723 shall be designed to verify the
validity of such determination.
6.
In determining the adequacy of proposed corrective action and in determining
the additional steps needed to prevent fluid movement into underground sources
of drinking water, the following criteria and factors shall be considered by
the commissioner:
a. nature and volume of
injection fluid;
b. nature of
native fluids or by-products of injection;
c. potentially affected population;
d. geology;
e. hydrology;
f. history of the injection
operation;
g. completion and
plugging records;
h. abandonment
procedures in effect at the time the well was abandoned; and
i. hydraulic connections with underground
sources of drinking water.
7. The Office of Conservation may prescribe
additional requirements for corrective action beyond those submitted by the
applicant.
AUTHORITY
NOTE: Promulgated in accordance with
R.S.
30:4 et seq. and
R.S.
30:23 et seq.
