| (vii) The director may exempt existing Class II wells
that have been associated with injection of CO2 for
the purpose of enhanced recovery, Class V experimental technology
wells, and stratigraphic test wells from provisions of these casing
and cementing requirements if the applicant demonstrates that the
well construction meets the general performance criteria in subparagraph
(A) of this paragraph. A converted well must meet all other requirements
under this section. The demonstration must include the following:
(I) as-built schematics and construction procedures
to demonstrate that repermitting is appropriate;
(II) recent or newly conducted well-log information
and mechanical integrity test results;
(III) a demonstration that any needed remedial actions
have been performed;
(IV) a demonstration that the well was engineered and
constructed to meet the requirements of subparagraph (A) of this paragraph
and ensure protection of USDWs;
(V) a demonstration that cement placement and materials
are appropriate for CO2 injection for
geologic storage;
(VI) a demonstration that the well has, and is able
to maintain, internal and external mechanical integrity over the life
of the project; and
(VII) the results of any additional testing of the
well to support a demonstration of suitability for geologic storage.
(C) Special equipment.
(i) Tubing and packer. All injection wells must inject
fluids through tubing set on a packer. Packers must be set no higher
than 100 feet above the top of the permitted injection interval or
at a location approved by the director.
(ii) Pressure observation valve. The wellhead of each
injection well must be equipped with a pressure observation valve
on the tubing and each annulus of the well.
(2) Construction information. The applicant must provide
the following information for each well to allow the director to determine
whether the proposed well construction and completion design will
meet the general performance criteria in paragraph (1) of this subsection:
(A) depth to the injection zone;
(B) hole size;
(C) size and grade of all casing and tubing strings
(e.g., wall thickness, external diameter, nominal weight, length,
joint specification and construction material, tubing tensile, burst,
and collapse strengths);
(D) proposed injection rate (intermittent or continuous),
maximum proposed surface injection pressure, external pressure, internal
pressure, axial loading, and maximum proposed volume and mass of the
CO2 stream to be injected;
(E) type of packer and packer setting depth;
(F) a description of the capability of the materials
to withstand corrosion when exposed to a combination of the CO2 stream and formation fluids;
(G) down-hole temperatures and pressures;
(H) lithology of injection and confining zones;
(I) type or grade of cement and additives;
(J) chemical composition and temperature of the CO2 stream; and
(K) schematic drawings of the surface and subsurface
construction details.
(3) Well construction plan. The applicant must submit
an injection well construction plan that meets the criteria in paragraph
(1) of this subsection.
(4) Well stimulation plan. The applicant must submit
a description of the proposed well stimulation program, including
a description of the stimulation fluids, and a determination that
well stimulation will not compromise containment.
(f) Plan for logging, sampling, and testing of injection
wells before injection. The applicant must submit a plan for logging,
sampling, and testing of each injection well prior to injection well
operation. The plan need not include identical logging, sampling,
and testing procedures for all wells provided there is a reasonable
basis for different procedures. Such plan is not necessary for existing
wells being converted to anthropogenic CO2 injection
wells in accordance with this subchapter, to the extent such activities
already have taken place. The plan must describe the logs, surveys,
and tests to be conducted to verify the depth, thickness, porosity,
permeability, and lithology of, and the salinity of any formation
fluids in, the formations that are to be used for monitoring, storage,
and confinement to assure conformance with the injection well construction
requirements set forth in subsection (e) of this section, and to establish
accurate baseline data against which future measurements may be compared.
The plan must meet the following criteria and must include the following
information.
(1) Logs and surveys of newly drilled and completed
injection wells.
(A) During the drilling of any hole that is constructed
by drilling a pilot hole that is enlarged by reaming or another method,
the operator must perform deviation checks at sufficiently frequent
intervals to determine the location of the borehole and to assure
that vertical avenues for fluid movement in the form of diverging
holes are not created during drilling.
(B) Before surface casing is installed, the operator
must run appropriate logs, such as resistivity, spontaneous potential,
and caliper logs.
(C) After each casing string is set and cemented, the
operator must run logs, such as a cement bond log, variable density
log, and a temperature log, to ensure proper cementing.
(D) Before long string casing is installed, the operator
must run logs appropriate to the geology, such as resistivity, spontaneous
potential, porosity, caliper, gamma ray, and fracture finder logs,
to gather data necessary to verify the characterization of the geology
and hydrology.
(2) Testing and determination of hydrogeologic characteristics
of injection and confining zone.
(A) Prior to operation, the operator must conduct tests
to verify hydrogeologic characteristics of the injection zone.
(B) The operator must perform an initial pressure fall-off
or other test and submit to the director a written report of the results
of the test, including details of the methods used to perform the
test and to interpret the results, all necessary graphs, and the testing
log, to verify permeability, injectivity, and initial pressure using
water or CO2 .
(C) The operator must determine or calculate the fracture
pressures for the injection and confining zone. The Commission will
include in any permit it might issue a limit of 90% of the fracture
pressure to ensure that the injection pressure does not exceed the
fracture pressure of the injection zone.
(3) Sampling.
(A) The operator must record and submit the formation
fluid temperature, pH, and conductivity, the reservoir pressure, and
the static fluid level of the injection zone.
(B) The operator must take whole cores or sidewall
cores representative of the injection zone and confining zone and
formation fluid samples from the injection zone. The director may
require the operator to core other formations in the borehole. The
director may accept data from cores and formation fluid samples from
nearby wells or other data if the operator can demonstrate to the
director that such data are representative of conditions at the proposed
injection well. The operator must submit to the director a detailed
report prepared by a log analyst that includes well log analyses (including
well logs), core analyses, and formation fluid sample information.
(g) Compatibility determination. Based on the results
of the formation testing program required by subsection (f) of this
section, the applicant must submit a determination of the compatibility
of the CO2 stream with:
(1) the materials to be used to construct the well;
(2) fluids in the injection zone; and
(3) minerals in both the injection and the confining
zone.
(h) Mechanical integrity testing.
(1) Criteria. This paragraph establishes the criteria
for the mechanical integrity testing plan for anthropogenic CO2 injection wells that an applicant must include
in an application.
(A) Other than during periods of well workover in which
the sealed tubing-casing annulus is of necessity disassembled for
maintenance or corrective procedures, the operator must maintain mechanical
integrity of the injection well at all times.
(B) Before beginning injection operations and at least
once every five years thereafter, the operator must demonstrate internal
mechanical integrity for each injection well by pressure testing the
tubing-casing annulus.
Cont'd... |
