Water Well Journal
Issue link: https://read.dmtmag.com/i/655200
Some aquifers are fairly broad, but not thick. In those cases, a conventional verti- cal well can quickly exhaust the water supply in a small zone around the well— the cone of depression—and run out of water. Depending on the permeability of the soil, recharge, and other factors, a vertical well might be limited in how hard you can pump it without stressing the aquifer. If you put in several wells, you need to connect them all and sometimes access becomes a big issue. In these circumstances, you can put a horizontal well near the bottom of the aquifer and extend it for hundreds of feet. This greatly increases the capacity of the well, and it still only has one well head to connect, one pump, etc. John McCray: Horizontal and angled wells should be much more effective than vertical wells if you deduct where the water-bearing formations are, but they are much more expen- sive to drill. Of course, a single horizontal or angular well might be as effective as four or five vertical wells, so it might actually end up being cheaper. WWJ: Is lithology an issue when deciding whether to use it? John: The basic idea behind a horizontal well is it can better access fluids for most geologic settings. Oil, gas, and ground- water all exist in porous geologic formations that are prima- rily sedimentary. In the case of oil it is the organic matter that turns into oil, and in the case of water the sediment fills up as water rains into it or as lakes form over it. David: If you are in a type of geology where a river cuts through the state and both sides of the river basin have diffi- culty getting water, we can drill parallel to the river basin or go under the river basin because many river basins are filled with gravel that was laid down with the water initially. We keep the horizontal incline, trying to avoid certain layers with lower quality water to find water that has lower total dissolved solids than the river water itself. Traut Wells installs the 40 slot Muni-Pak well screen for the third well at a 15° angle. The angle allows them to increase the screen's length, which in turn increases the well's yield. David Traut, MGWC, CVCLD waterwelljournal.com 30 April 2016 WWJ ANGLED WELLS from page 29 ...the instrument of choice for professionals worldwide Water Level Meters s Well Casing Indicators Well Depth Indicators s Data Loggers s Temperature Meters Conductivity Meters s Interface Meters s Pressure Transmitters Tag Lines s Borehole Inspection Cameras Made in Canada www.heroninstruments.com s 1-800 -331-2032