| (iii) Any alternate casing program shall include pumping
sufficient cement to fill the annular space from the shoe or multi-stage
tool to the ground surface. If cement is not circulated to the ground
surface or the bottom of the cellar, the operator shall run a temperature
survey or cement bond log. The appropriate district office shall be
notified prior to running the required temperature survey or bond
log. After the top of cement outside the casing is determined, the
operator or the operator's representative shall contact the appropriate
district director and obtain approval for the procedures to be used
to perform any required additional cementing operations. Upon completion
of the well, a cementing report shall be filed with the Commission
on the prescribed form.
(iv) Before parallel (nonconcentric) strings of pipe
are cemented in a well, surface or intermediate casing must be set
and cemented through the protection depth.
(I) Mechanical integrity test of surface casing after
drillout.
(i) If the surface casing is exposed to more than 360
rotating hours after reaching total depth or the depth of the next
casing string, the operator shall verify the integrity of the surface
casing by using a casing evaluation tool or conducting a mechanical
integrity test or equivalent Commission-approved casing evaluation
method, unless otherwise approved by the district director.
(ii) If a mechanical integrity test is conducted, the
appropriate district office shall be notified at least eight hours
before the test is conducted to give the district office an opportunity
to witness the test. The operator shall use a chart of acceptable
range (20% - 80% of full scale) or an electronic equivalent approved
by the district director, and the surface casing shall be tested at
a pump pressure in pounds per square inch (psi) calculated by multiplying
the length of the true vertical depth in feet of the casing string
by a factor of 0.5 psi per foot up to a maximum of 1,500 psi for a
minimum of 30 minutes. A pressure test demonstrating less than a 10%
pressure drop after 30 minutes constitutes confirmation of an acceptable
pressure test. The appropriate district office shall be notified within
24 hours after a failed test. Completion operations may not re-commence
until the district director approves a remediation plan and the operator
successfully implements the approved plan, and successfully re-tests
the surface casing.
(2) Intermediate casing requirements for land wells
and bay wells.
(A) Cementing method. Each intermediate string of casing
shall be cemented from the shoe to a point at least 600 feet (measured
depth) above the shoe. If any productive zone, potential flow zone,
or zone with corrosive formation fluids is open to the wellbore above
the casing shoe, the casing shall be cemented;
(i) if the top of cement is determined through calculation,
from the shoe up to a point at least 600 feet (measured depth) above
the top of the shallowest productive zone, potential flow zone, or
zone with corrosive formation fluids;
(ii) if the top of cement is determined through performance
of a temperature survey, from the shoe up to a point at least 250
feet (measured depth) above the top of the shallowest productive zone,
potential flow zone, or zone with corrosive formation fluids;
(iii) if the top of cement is determined through performance
of a cement evaluation log, from the shoe up to a point at least 100
feet (measured depth) above the top of the shallowest productive zone,
potential flow zone, or zone with corrosive formation fluid; or
(iv) to a point at least 200 feet (measured depth)
above the shoe of the next shallower casing string that was set and
cemented in the well (or to surface if the shoe is less than 200 feet
from the surface); or
(v) as otherwise approved by the district director.
(B) Top of cement. The calculated or measured top of
cement shall be indicated on the appropriate completion form required
by §3.16 of this title (relating to Log and Completion or Plugging
Report).
(C) Alternate method. In the event the distance from
the casing shoe to the top of the shallowest productive zone, potential
flow zone, and/or zone with corrosive formation fluids make cementing,
as specified above, impossible or impractical, the multi-stage process
may be used to cement the casing in a manner that will effectively
isolate and seal the zones to prevent fluid migration to or from such
strata within the wellbore.
(3) Production casing requirements for land wells and
bay wells.
(A) Centralizers. In deviated and horizontal holes,
the operator shall provide centralization as necessary to ensure zonal
isolation between the top of the interval to be completed and the
shallower zones that require isolation.
(B) Cementing method. The production string of casing
shall be cemented by the pump and plug method, or another method approved
by the Commission, with sufficient cement to fill the annular space
back of the casing to the surface or to a point at least 600 feet
above the shoe. If any productive zone, potential flow zone and/or
zone with corrosive formation fluids is open to the wellbore above
the casing shoe, the casing shall be cemented in a manner that effectively
seals off all such zones by one of the methods specified for intermediate
casing in paragraph (2) of this subsection. A float collar or other
means to stop the cement plug shall be inserted in the casing string
above the shoe. Cement shall be allowed to stand under pressure for
a minimum of eight hours before drilling the plug or initiating casing
pressure tests. In the event that the distance from the casing shoe
to the top of the shallowest productive zone, potential flow zone
and/or zone with corrosive formation fluids make cementing, as required
above, impossible or impractical, the multi-stage process may be used
to cement the casing in a manner that will effectively seal off all
such zones, and prevent fluid migration to or from such zones within
the wellbore. Uncemented casing is allowable within a producing reservoir
provided the production casing is cemented in such a manner to effectively
isolate and seal off that zone from all other productive zones in
the wellbore as required by §3.7 of this title (relating to Strata
To Be Sealed Off).
(C) Reporting of top of cement. Calculated or measured
top of cement shall be indicated on the appropriate completion form
required by §3.16 of this title.
(D) Isolation of gas/oil contact zones. The position
of the gas-oil contact shall be determined by coring, electric log,
or testing. The producing string shall be landed and cemented below
the gas-oil contact, or set completely through and perforated in the
oil-saturated portion of the reservoir below the gas-oil contact.
(4) Tubing requirements for land wells and bay wells.
(A) Tubing requirements for oil wells. All flowing
oil wells shall be equipped with and produced through tubing. When
tubing is run inside casing in any flowing oil well, the bottom of
the tubing shall be at a point not higher than 100 feet (vertical
depth) above the top of the producing interval nor more than 50 feet
(vertical depth) above the top of the liner, if a liner is used, or
100 feet (vertical depth) above the kickoff point in a deviated or
horizontal well. In a multiple zone structure, however, when an operator
elects to equip a well in such a manner that small through-the-tubing
type tools may be used to perforate, complete, plug back, or recomplete
without the necessity of removing the installed tubing, the bottom
of the tubing may be set at a distance up to, but not exceeding, 1,000
feet (vertical depth) above the top of the perforated or open-hole
interval actually open for production into the wellbore.
(B) Alternate tubing requirements. Alternate programs
requesting a temporary exception pursuant to subsection (d) of this
section to omit tubing from a flowing oil well may be authorized on
an individual well basis by the appropriate district director. The
district director shall deny the request if the operator has not demonstrated
that the alternative tubing plan will achieve the intent as described
in subsection (a)(1) of this section. If the proposal is rejected,
the operator may request a review by the director of field operations.
If the proposal is not approved administratively, the operator may
request a hearing. An operator shall obtain approval of any alternative
program before commencing operations.
(c) Casing, cementing, drilling, and completion requirements
for offshore wells.
(1) Casing. An offshore well shall be cased with at
least three strings of pipe, in addition to such drive pipe as the
operator may desire, which shall be set in accordance with the following
program.
Cont'd... |
