Current through Register Vol. 42, No. 11, August 30, 2024
(1) The operator shall case and cement all
wells with a sufficient number of strings in a manner necessary to:
(a) prevent communication between separate
hydrocarbon-bearing strata (except such strata approved for commingling) and
between hydrocarbon and water-bearing strata;
(b) prevent contamination of
freshwater-bearing strata;
(c)
support unconsolidated sediments; and
(d) otherwise provide a means of controlling
formation pressures and fluids.
(2) The operator shall install casing that
meets American Petroleum Institute (API) standards. Standard cement shall be
used and shall be mixed with water of adequate quality so as not to degrade the
setting properties. Safety factors in casing program design shall be of
sufficient magnitude to provide optimum well control while drilling and to
assure safe operations for the life of the well.
(a) Surface Casing. The minimum amount of
surface casing to be set below ground level, the cement requirements and the
test pressure requirements shall be determined from Table 1.
TABLE 1
Proposed True Vertical Minimum Casing
Depth (TVD) (ft) Required (ft) Cement required Surface
test-pressure (psi)
0 - 4,000 300 Circulate to surface 300
4,001 - 5,000 400 Circulate to surface 600
5,001 - 6,000 600 Circulate to surface 800
6,001 - 7,000 800 Circulate to surface 1,000
7,001 - 8,000 1,000 Circulate to surface 1,000
8,001 - 9,000 1,400 Circulate to surface 1,000
Greater than 9,000 1,800 Circulate to surface 1,500
The Supervisor may specify surface casing requirements other
than those set forth in Table 1 if such requirements are needed to provide for
increased protection of freshwater resources.
(b) Production Casing. All producing wells
shall be completed with a production string of casing that shall be properly
cemented at a sufficient depth adequate to protect the methane bearing
coalbeds.
1. For cased hole completions or
cased/open hole completions, casing shall be cemented in place with a
calculated volume of cement sufficient to fill the annular space at least two
hundred (200) feet above the top of the uppermost coalbed which is to be
completed, except that the annular space adjacent to a coalbed or coalbeds may
be left uncemented.
2. For open
hole completions, the bottom of production casing shall be set not more than
one hundred (100) feet above the depth of the uppermost coalbed which the
operator intends to complete, unless prior approval is granted by the
Supervisor. The casing shall be cemented with a calculated volume of cement
sufficient to fill the annular space at least two hundred (200) feet above the
base of the casing.
(c)
The Supervisor may approve an alternative casing program upon written
justification by the operator.
(3) If there are indications of inadequate
primary cementing (such as lost returns, cement channeling, or mechanical
failure of equipment) of the surface or production casing strings, the operator
shall evaluate the adequacy of the cementing operations by pressure testing the
casing shoe, running a cement bond log or a cement evaluation tool log, running
a temperature survey, or a combination thereof before continuing operations. If
the evaluation indicates inadequate cementing, the operator shall re-cement or
take other actions as approved by the Supervisor. The operator shall verify the
adequacy of the remedial cementing operations as described above.
(4) Pressure Testing. An operator shall give
notice to the Supervisor prior to pressure testing.
(a) After primary cementing of surface
casing, drilling shall not be resumed until a time lapse of twelve (12) hours
under pressure. Cement is considered under pressure when one or more float
valves are employed and are shown to be holding the cement in place or when
other means of holding pressure are used. After cementing and prior to drilling
the plug, surface casing shall be pressure tested as set forth in Table 1
above. All pressure tests are to be held for thirty (30) minutes. If during
this test period the pressure declines more than ten percent (10%) of the
initial test pressure, then such corrective measures shall be taken to insure
that the casing string is so set and cemented that it will hold the test
pressure for thirty (30) minutes without a drop of more than ten percent
(10%).
(b) Upon conclusion of the
drilling of the well, or prior to the setting of production casing, the surface
casing shall be re-tested in accordance with Rule
400-3-4-.09(2)(a)
in order to verify the integrity of the casing string. This requirement will
not apply if the well is permitted to be drilled to a total depth of less than
six thousand (6,000) feet and no problems are encountered during the drilling
of such well that would require a retest to verify the mechanical integrity of
its surface casing string.
(c)
After primary cementing of production casing, drilling shall not resume until a
time lapse of twelve (12) hours under pressure. Cement is considered under
pressure when one or more float valves are employed and are shown to be holding
the cement in place or when other means of holding pressure are used. After
cementing and prior to drilling the plug, production casing shall be pressure
tested at a pressure of six hundred (600) pounds per square inch (psi), if the
plug is to be drilled. All pressure tests are to be held for thirty (30)
minutes. If during this test period the pressure declines more than ten percent
(10%) of the initial test pressure, then corrective measures shall be taken to
insure that the casing string is so set and cemented that it will hold the test
pressure for thirty (30) minutes without a drop of more than ten percent (10%)
unless otherwise approved by the Supervisor.
(5) Recording Test Pressures.
(a) Proper documentation of pressure tests,
including beginning and ending pressures and the duration of each test shall be
recorded in a daily drilling report.
(b) Unless witnessed by an agent of the
Board, all pressure tests and retests shall be documented with a properly
calibrated continuous pressure recorder or other pressure recording device
acceptable to the Supervisor. A representative of the operator shall sign the
pressure test record(s) following completion of each pressure test.
(c) The operator shall maintain all pressure
test records at the well site during drilling operations. Such records shall be
made available for inspection upon request.
(d) The operator shall maintain all pressure
test records for a minimum of three (3) years from the date such pressure tests
were conducted.
(6)
Reporting Test Pressures. The operator shall report casing pressure tests on
Form OGB-7.
Author: State Oil and Gas Board
Statutory Authority:
Code of Ala.
1975, §§
9-17-1, et
seq.
