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Water wells have been around for a long time, and some of the methods of cleaning, developing and rehabilitating them have been around almost as long. When rehabilitation is called for, even today, 1950s-vintage techniques, chemicals and equipment are sometimes used. Chemicals are simply poured in, surged and pumped out 12 hours later, with little or no idea of how effectively the process has worked until pumping rates are checked afterwards. A combination of physical and chemical cleaning provides the most cost-effective treatment. Before chemical treatment, the well should be physically cleaned as thoroughly as possible. This will reduce the amount of chemistry required to finish the job. | ||||||||||||||||||||
| Brushing or scraping | |||||||||||||||||||||
| Traditional methods include a wire brush and scraper to dislodge debris from inside the casing and screen. Brushing and scraping are effective inside the well screen and casing, but have virtually no effect on the surrounding formation. | |||||||||||||||||||||
| Surging | |||||||||||||||||||||
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Surging (agitation of the well with a plunging device called a surge block) is another traditional technique. Surging is somewhat effective in reaching into the surrounding aquifer, but doesn't provide consistent cleaning throughout the length of the screen. Surging is most effective near the bottom of the screen and progressively less so the closer the surge block gets to the top of the screen. Surging can cause channeling through the screen into the porous formation, leaving layers of silty, finer-grained particle formations undeveloped. If obstructing materials such as silt, sand and scale aren't physically removed from the well and its surrounding formation, the process can't truly be called development. |
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| Jetting | |||||||||||||||||||||
| The most effective way to clean the well screen and rehabilitate the surrounding aquifer jetting - shooting jets of water or other fluids through the screen and into the formation while simultaneously pumping the dislodged materials out of the well. The specialized jetting technique employed by Northwest Hydro-Fracturing is described in detail in a later section. | |||||||||||||||||||||
| Chemical treatment | |||||||||||||||||||||
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Over the years, a wide variety of chemical solutions have been devised to treat specific types of biological deposits and mineral scale. On their own, simply poured into a well, even the best chemicals have only limited effectiveness. Physical cleaning action is also required. Unfortunately, even today, most chemicals are hazardous and often aren't handled with sufficient care, sometimes endangering personnel, the aquifer, and the well site. Great care should always be taken in the application, removal and disposal of chemicals. For any of these techniques to be truly considered development, the scale and other debris dislodged from the well, and any chemicals used in the process, must be pumped out of the well for proper disposal. Redistribution of debris is not development. In fact, methods that simply blow holes into a blocked or biofouled formation can actually accelerate the reoccurrence of blockage and biofouling. |
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| To determine if hydro-fracturing is right
for 509-466-5078 · 800-368-0998 Email: djminden@msn.com |
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