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 Guidancz No. 5 wysiwyg://35/hup://www.epa.gov/reg5oh2o/uic/r5_o5.htm
• •
pressure allows the leak to resume. This is why it is important [o ensure a pressure differen
between the injection tubing and annulus.
If annulus pressure is lower than injection pressure and both the tubing and casing are leaki
any tracer material that leaks out of [he tubing will generally move toward and out through
casing leak. This is because the annulus pressure normally will be higher than the hydrostat
pressures within adjacent formations at all depths.
If only [he tubing is leaking, the tracer material will remain near the leak, spreading slowly
both up and down from the leak location.
Adherence of tracer material to the tubing can be differentiated from a tubing leak because
material adhering to the tubing will eventually be washed away with no movement evident
If no evidence of leaking is observed, the well has demonstrated part 1 of MI. Be aware that
demonstrations of MI using [he RTS will be examined very closely, and any conditions which
threaten [he ability to interpret them accurately must be removed.
ATTACHMENT4
WATER-BRINE INTERFACE TEST (W-BIT)
A. Basis
The water-brine interface test is based on:
The differences in liquid pressure gradients of the brine filling salt solution mining caverns
fresh water;
2. Pressurization of the cavern resulting from salt-solution mining; and
3. Pascal's Law, the transmission of pressure throughout a closed vessel.
The strategy governing [he test is [ha[ a decrease in wellhead pressure will be observed in the eve
of loss of a fluid of lower density filling a standpipe open to a reservoir filled with a fluid of high
density. In practice, this situation is produced by:
Flushing the well to be tested with sufficient fresh water to dissolve any salt precipitated of
interior of the casing;
2. Withdrawing water until cavern brine is brought to the surface; and
3. Depressing the cavern brine [o [he base of the well casing by the injection of a volume of fl
water sufficient to fill the casing to within 25 feet of the casing shoe.
Because the cavern is pressurized sufficiently to cause the heavy brine [o flow to the surface, the
pressure within the well filled with fresh water is greater than the hydrostatic pressures in any aqt
through which the well passes. Therefore, any leak will allow fresh water to flow outward, to be
replaced by dense brine flowing into the well from the cavern. Because the liquid pressure gradie
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