HYDRO29443

• Permit No: M1999002
• IBM Index Class Name: Hydrology
• Doc Date: 5/28/1999
• Doc Name: UIC INFO
• Media Type: D
• Archive: No

Underground Injection Control Branch Guidance No.~
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the casing precludes the use of logging techniques, cementing records demonstrating the presence of
adequate cement to prevent fluid migration into USDWs pursuant to 40 CFR § 146.8(c)(2) and (c)(3)
respectively. Demonstrations of both pan l and part 2 of MI must be made before injection can be
authorized.
The procedures which are recommended in the attachments to this document will, in most cases, result
development of valid data which Region 5 will be able to interpret with confidence. Deviations from [h
procedures may result in anomalies which will complicate or even invalidate test results. If the
recommended test results do not result in definitive information, any anomalies noted should be
investigated immediately, including re-doing the tests. Results which provide demonstrations of MI are
purpose of this guidance, but adherence to guidance may not ensure development of acceptable results i
cases. In such cases, mere adherence to guidance does not absolve the operator from the requirement to
demonstrate MI. In cases in which there is doubt about the certainty of outcomes, reference [o and
compazison with previous tests can often be used to clarify the test results. In this vein, comparison of t.
through time, especially the comparison of temperature and radioactive tracer logs can make interpretat
easier and make progressive change apparent. In all cases, operators should submit proposed testing
procedures to the UIC Branch's Direct Implementation (DI) Section for approval before the testing is do
This can prevent misunderstandings and possible retesting.
III.
A. Mechanical Integrity Pursuant to 40 CFR § 146.8(a)(1)
There are a limited number of means by which part 1 of MI (the absence of significant leaks in tubing.
casing, and packer) may be demonstrated. Therefore, little discussion of the relative merits of the variot
tests is necessary.
1. The Standard Annulus Pressure Test (SAPT)
The SAPT is the most common means used [o demonstrate part 1 of MI. This test is based on the princi
that a pressure applied to fluids filling a sealed vessel will persist. A well's annulus system, though clos
to transfer of matter, is not closed to energy transfer because it is not isolated from transfer of heat from
surroundings, therefore an allowance for small pressure changes is necessary. The test provides an
immediate demonstration of whether or not leaks, detectable by these means, exist. A discussion of and
procedures for [he SAPT are outlined in Attachment 1.
2. The Standard Annulus Monitoring Test (SAMT)
Pursuant to 40 CFR § 146.8(6), monitoring of the annulus pressure is an approved method for establish
part 1 of MI for all wells. Annulus pressure monitoring for Class I wells required a[ § 146.13(6)(2) to ve
the maintenance of a minimum pressure differential is not the SAMT, because changes in pressure due
loss of annulus liquid are attenuated by the presence of a gas blanket which is replenished as pressure
decreases. If annulus monitoring is used to demonstrate MI, an initial SAPT is required. Annulus
monitoring may continue throughout the life of the well or the operator may choose, at any time, to con
a SAPT every five years and after well reworks (on rule authorized Class II wells and on permitted well
the particular UIC permit allows it), thereby discontinuing the SAMT. A discussion of the merits and
procedures for the SAMT is provided in Attachment 2.
3. The Radioactive Tracer Survey (RTS)
On September 18, 1987, the USEPA published a Federal Register (FR) notice at 35324 et seq. FR 52,1`
181, giving interim approval for [he use of the RTS as an alternative MIT. In a FR Notice at 46837 et se
FR 52, No. 237 on December 10, 1987, the USEPA announced final approval of [he RTS as a
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