California River Well Rehab
Hopkins Groundwater Consultants, Inc. and WellJet recently teamed up to rehabilitate a river well in central California.
The well was drilled in 1998 to a total depth of 60 feet, and constructed with a stainless steel wire-wrapped screen placed between the depths of 25 and 45 feet.
The well originally produced at a rate of 600 fpm resulting in a drawdown of 5 feet and a specific capacity of 120 gpm/ft of drawdown.
Recently, well performance and efficiency had declined, and routine monitoring indicated an increasing drawdown and a reduced specific capacity value of 40 gpm/ft.
The hydrogeology consultant on the project, Mr. Curtis Hopkins, studied the well conditions and concluded that a majority of the plugging was in the formation material surrounding the well screen. To rehabilitate the well, Mr. Hopkins recommended a combination of WellJet along with simultaneous evacuation of dislodged material via suction pump and hose.
WellJet mobilized to the site, positioning the pump and reel unit close to the well, alongside the pump and vacuum hose setup that Hopkins Groundwater deployed. As the well was located in an environmentally sensitive area, several hundred feet of tubing was utilized to remove wastewater and dislodged deposits from the well area, and discharge safely away from the river.
There was demonstrable evidence that WellJet delivered energy into the gravel pack and surrounding formation materials, as silt and fine-to-coarse-grained sand was removed from the well screen interval.
WellJet’s effectiveness was also clearly documented in the Before & After video survey comparison.
Results were successful. The specific capacity improved from 40 gpm/ft t0 180 gpm/ft, an increase of 450% over pre-rehab performance – and even 50% better than when the well was new.
