HYDRO24705

• Permit No: M1983194
• IBM Index Class Name: Hydrology
• Doc Date: 2/20/2004
• Doc Name: Plan to Cement Subsidence Monitoring Well 3M-TDR
• From: Natural Soda Inc.
• To: DMG
• Media Type: D
• Archive: No

~~~ ~ ~-~~
NATURAL SODA, INC. L ~ ~` ~~'`- y ~ i i
3200 County Rd. 31 Phone: [phone]
Rifle, Colorado 81650 Fax: [phone]
1/
February 18, 2004 ~ ~ 1~ w l: ~~ h+'~ j~ ~ 3 _ ~ 9
Mr. Gregg R. Squire RECEIVED
Environmental Protection Specialises FEB 2 0 2004
Division of Minerals and Geology
1313 Sherman Street, ROOM 315 Division of Minerals & Geology
Denver, Colorado 80203
Subject: ~. Plan to Cement Subsidence Monitoring We113M-TDR
Dear Mr. Squire,
Subsequent to our letter of October 24, 2003, which provided we113M-TDR
completion details, cement bond, CCL and caliper logs; additional logs and
data have been obtained. After completion of we113M-TDR the water
balance to and from the well field has been abnormally equal. Typically, the
injection flow exceeds the recovery flow by 10-15 gpm to compensate for
volume of nahcolite dissolved. Additions in the facility from centrifuge
wash, pump seal leaks, heat exchanger wash, and clean up water is off-set by
the nahcolite displacement. As a result of limited or no consumption of
water, the process pond is full and Dissolution Surface wells are barely
within piezometric limits. This water balance problem coincides with the
eazly October 2003 completion of 3M-TDR.
A portion of the caliper log (10-5-03) is attached, which indicates a "wash-
out" zone from 1712' to 1760' feet from surface (FFS). The cement bond
log (10-10-03) attached, indicates the good cement top at ~ 1760' FFS.
Temperature logs from 11-7-03 and 1-13-04 indicates a temperature gradient
from top to bottom of less than 10 degrees F. A gradient of 15 degrees F per
1000 feet is typical, therefore we would except a temperature change of
greater than 20 degrees F. As a result, NSI believes there is a flow of 8-15
gpm down the annulus of 3M-TDR from the A, B Grooves, and Perched
aquifers. NSI attempted to shut off the flow by trying to do a remedial
cement job using three perforations in the casing at ~ 1650' FFS. This
attempt involved setting a retrievable plug (CIBP) covered with sand just
below the perforations and pumping 9.5 sacks of sodium silicate followed by