Applications of High-Pressure Hydrojetting in Water Well Development and Rehabilitation
It's not magic. You'll just think it is.
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“WellJet® was so good, we are mandating it on all of our new wells.”
Although recent California winters have been wetter than usual, the default condition of the state is one of water scarcity – due to geography, climate, and a burgeoning human population. 85% of Californians depend on groundwater for at least some of their water needs. For residents in a particular Water District south of Santa Cruz, that figure is 100%.
It’s vital that the District’s groundwater wells perform at peak efficiency, to control costs in this challenging economic environment, and, as responsible public servants, to shrink the carbon footprint and energy consumption of groundwater production.
To continue providing safe, reliable water to its 40,000 customers, the District elected to have a new well drilled. A highly respected southwest hydrogeology firm provided the well design, and consulting services throughout the construction and development process. An experienced drilling contractor with 30 rigs and 70 employees won the drilling contract.
Well #2 was situated on a small plot of land in a crowded residential neighborhood. To reduce the noise impact of operations, the driller constructed an impressive series of sound-baffling walls.
The well was drilled to a total depth of 540’, with a diameter of 16”.
Based on e-logs showing the disposition of water-bearing strata in the formation, stainless steel wire-wrapped screens were placed at 257-307, and 340-530, a total of 240’ of perforated area. Static water level in the well was 182’.
The contractor drilled and developed the well using their standard practices that have proven successful for decades, but performance was suboptimal. This was due at least in part to shallow submergence limiting the effectiveness of airlifting. The well was producing approximately 400 gpm, with 73’ of drawdown, for a Specific Capacity of 5.5 gal/ft/minute – less than targeted output, with considerably less than desired efficiency.
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