Current through Register Vol. 48, No. 38, September 20, 2024
a) All
Class I injection wells must be sited in such a fashion that they inject into a
formation which is beneath the lowermost formation containing, within 402
meters (one-quarter mile) of the well bore, an underground source of drinking
water.
b) All Class I injection
wells must be cased and cemented to prevent the movement of fluids into or
between underground sources of drinking water. The casing and cement used in
the construction of each newly drilled well must be designed for the life
expectancy of the well. In determining and specifying casing and cementing
requirements, the following factors must be considered:
1) The depth to the injection zone;
2) The injection pressure, external pressure,
internal pressure, and axial loading;
3) The hole size;
4) The size and grade of all casing strings
(wall thickness, diameter, nominal weight, length, joint specification, and
construction material);
5) The
corrosiveness of injected fluid, formation fluids, and temperatures;
6) The lithology of injection and confining
intervals; and
7) The type or grade
of cement.
c) A Class I
injection well, except a municipal well injecting non-corrosive wastes, must
protect underground sources of drinking water against movement of fluids from
the injection zone upward through the well. An operator may do this by
injecting fluids through tubing with a packer set immediately above the
injection zone, or tubing with an approved fluid seal as an alternative. The
tubing, packer, and fluid seal must be designed for the expected service.
1) The use of other alternatives to a packer
may be allowed with the written approval of the Agency. To obtain approval, the
operator must submit a written request to the Agency that sets forth the
proposed alternative and all technical data supporting its use. The Agency must
approve the request if the alternative method will reliably provide a
comparable level of protection to underground sources of drinking water. The
Agency may approve an alternative method solely for an individual well;
however, the Agency may promulgate criteria approving alternatives pursuant to
35 Ill. Adm. Code
702.106.
2) In determining and specifying requirements
for tubing, packer, or alternatives the following factors shall be considered:
A) The depth of setting;
B) Characteristics of the injection fluid
(chemical content, corrosiveness, and density);
C) The injection pressure;
D) The annular pressure;
E) The rate, temperature, and volume of
injected fluid; and
F) The size of
casing.
d)
Appropriate logs and other tests must be conducted during the drilling and
construction of new Class I injection wells. A descriptive report interpreting
the results of such logs and tests must be prepared by a knowledgeable log
analyst and submitted to the Agency. At a minimum, such logs and tests must
include the following information:
1)
Deviation checks on all holes constructed by first drilling a pilot hole, and
then enlarging the pilot hole by reaming or another method. Such checks must be
at sufficiently frequent intervals to assure that vertical avenues for fluid
migration in the form of diverging holes are not created during
drilling.
2) Such other logs and
tests as may be needed after taking into account the availability of similar
data in the area of the drilling site, the construction plan, and the need for
additional information, that may arise from time to time as the construction of
the well progresses. In determining which logs and tests must be required, the
following logs must be considered for use in the following situations:
A) For surface casing intended to protect
underground sources of drinking water, the following:
i) Resistivity, spontaneous potential, and
caliper logs before the casing is installed; and
ii) A cement bond, temperature, or density
log after the casing is set and cemented.
B) For intermediate and long strings of
casing intended to facilitate injection, the following:
i) Resistivity, spontaneous potential,
porosity, and gamma ray logs before the casing is installed;
ii) Fracture finder logs; and
iii) A cement bond, temperature, or density
log after the casing is set and cemented.
e) At a minimum, the following
information concerning the injection formation must be determined or calculated
for new Class I injection wells:
1) Fluid
pressure;
2) Temperature;
3) Fracture pressure;
4) Other physical and chemical
characteristics of the injection matrix; and
5) Physical and chemical characteristics of
the formation fluids.
