| (v) At least one long string casing, using a sufficient
number of centralizers, must extend through the injection zone. The
long string casing must isolate the injection zone and other intervals
as necessary for the protection of underground sources of drinking
water and to ensure confinement of the injected and formation fluids
to the permitted injection zone using cement and/or other isolation
techniques.
(vi) The applicant must verify the integrity and location
of the cement using technology capable of radial evaluation of cement
quality and identification of the location of channels to ensure that
underground sources of drinking water will not be endangered.
(vii) The director may exempt existing wells that have
been associated with injection of CO2 for
the purpose of enhanced recovery 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.
(C) Special equipment.
(i) Tubing and packer. All injection wells must inject
fluids through tubing set on a mechanical 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, and maximum proposed
volume of the CO2 stream;
(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,
as applicable, a description of the proposed well stimulation program
and a determination that well stimulation will not compromise containment.
(f) Plan for logging, sampling, and testing of injection
wells after permitting but before injection. The applicant must submit
a plan for logging, sampling, and testing of each injection well after
permitting but 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. If the fracture pressures
are determined through calculation, the Commission will include in
any permit it might issue a limit of 90% of the calculated fracture
pressure to ensure that the injection pressure does not exceed the
fracture pressure.
(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 submit analyses of whole cores
or sidewall cores representative of the injection zone and confining
zone and formation fluid samples from the injection zone. 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.
(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 mechanical
integrity for each injection well by pressure testing the tubing-casing
annulus.
(C) Following an initial annulus pressure test, the
operator must continuously monitor injection pressure, rate, injected
volumes, and pressure on the annulus between tubing and long string
casing to confirm that the injected fluids are confined to the injection
zone.
(D) At least once every five years, the operator must
confirm that the injected fluids are confined to the injection zone
using a method approved by the director (e.g., diagnostic surveys
such as oxygen-activation logging or temperature or noise logs).
(E) The operator must test injection wells after any
workover that disturbs the seal between the tubing, packer, and casing
in a manner that verifies mechanical integrity of the tubing and long
string casing.
Cont'd... |
