Installation of Aquastream Unit to Control Sand Pumping in a Denver Basin Well

A Denver Basin well for a water district in the Colorado Springs area was drilled in 1971 to a depth of 908 feet. The well was gravel packed and completed with 300 feet of shutter screen in the Arapahoe aquifer. The original static water level was 390 feet. The original capacity was 250 gpm with a specific capacity of 1.2 gpm per foot of drawdown.

During routine maintenance in 1988 the well was inspected with a down hole video survey. The shutter screen was found to be approximately 70 percent plugged. The well was Sonar-Jetted, treated using a solution of sodium hypochlorite with a surfactant, wire brushed, and surged. During bailing to remove deposits from the well, it was evident that gravel pack was entering the well through the slots of the shutter screen. The enlargement of the slot openings may have developed from water flow erosion or electrolytic corrosion.

An Aquastream unit that was 119 feet in length was attached to a new submersible pump and installed in the well. Upon completion of this work, the well produced 248 gpm with a specific capacity of 1.9 gpm per foot of drawdown, an improvement of 158 percent of original performance.

Installation of an Aquastream Unit to Control Sand Pumping in an Alluvial Well

A municipal well in the alluvium of the South Platte River was completed to a depth of 80 feet in alluvial materials, with 13 feet of 16-inch shutter screen set at the bottom of the well. By 1989, the well was producing so much sand that it could no longer be operated economically. A down hole video survey was performed, and holes in the casing and screen were identified at several locations. After bailing the well clean to total depth, an Aquastream unit was installed opposite the screen and a blank PVC liner was installed to the ground surface. A vertical turbine pump was then installed inside the liner. The well was tested and found to produce 451 gpm of sand free water.

SUMMARY

In summary, new water well rehabilitation procedures and techniques are proving that well rehabilitation and treatment is effective in restoring well yield in an economical manner. The Aquastream suction flow control device can also be a cost-effective means of salvaging sand producing well.

ACKNOWLEDGEMENTS

The authors would like to thank Dan Callahan of Layne-Western Company for providing the data used for the case histories.