GENERAL35422 - Laserfiche WebLink

Home Browse Search

• was added to the cement prior to pumping. This was performed by mixing the cement/plug gel in a lazge (150 gallon) tank (see figures 10 and l1). Once the cement was mixed, the mixriire was then pumped down the well through the tremie pipe until the cement was circulated to the surface. Additional cement was added as the tremie was extracted to ensure full cementing of the casing and annulus to ground surface. If the cement did not reach the surface in the first pumping, the tremie pipe was then partially extracted from the well, to a point were additional cement was mixed and pumped into the well until cement circulated to the surface. Then the tremie pipe was removed and additional cement added to ensure cement was seen at the surface. To place the concrete cap on top of the bedrock well, a 7.875" tri-wne bit was used to drill a hole 10 feet below ground surface after the well was filled with cement. This hole was then filled with concrete to near ground surface. A metal stake was then placed in the cement on which a metal tag with the alpha-numeric identification designation (see Well Data Table) for the well. The area was then smoothed, raked and seeded, with the previously described seed mixture. For those bedrock holes where the geophysical probe did not reach the recorded total depth, two options ensued. The first option required the washing of the well with'/." flexible black plastic tubing inserted into the well and flushing the well with clean water, until the projected depth was reached. If this did not work, the second option was the drilling of the well with a • 4" drag bit to the projected total depth. The wells that were drilled out are noted on the well data table at the end of this report. If the hole was flushed, and total depth was reached, the Goodwell crew was bought back to perforate these wells to aid in cementing. Following the perforation completion or drill out of the well casing, the hole was cemented following the procedure previously described. During the course of the project, no well exhibited flowing artesian conditions. Since the permeable zones in each well were unidentified, whether artesian conditions were present is not known. However, using the abandonment techniques previously discussed, any artesian layers were fully cemented and sealed. Field data on the wells sealed and abandoned during this project are included in the Well Data Table located at the end of this report. This table lists the wells abandoned and by what means by EFC during the course of the project. The table also lists those holes not abandoned by EFC due to possible use as water supply wells or for monitoring purposes by BLM. Following the completion of the abandonment, the Colorado Division of Minerals and Geology Coai Exploration Drill Hole or Well Abandonment Report was prepazed. A copy of this report is included with this report. CT&E Geologic Services 3 January 30, 2003 Gillette, Wyormng