Learn All About the Hydrofracturing Process
There are many reasons for a private water well to produce less water as it ages. Sometimes the cause is natural, for example, low rain conditions or drought. Other times it can be overuse of the aquifer or sediment clogging the fractures in the well that allow water to flow freely.
One method well water professionals use to open new and existing fractures in a well is called hydrofracturing. This is a process that involves injecting water under extreme pressure via your well into the bedrock formation immediately surrounding it. This process is intended open new fractures and widens existing fractures in the rock to extend them further into the formation and enlarge the network of water-bearing fractures which supply water to your well.
Hydrofracturing is a cost-effective way to increase the yield of existing wells with insufficient recharge rates or existing older wells that have decreased production due to incrustation or mineralization of the existing bedrock fractures.
A Little Hydrofracturing History...
Hydrofracturing as a restorative well water technique can trace its origins back to the oil and gas industry. It originally was developed and used to increase production in the oil and natural gas fields. It's been adopted by well water industry for use in private wells.
There are other methods of increasing well yield including using dynamite and CO2 or dry ice. Both are uncontrolled as to their effectiveness. In some areas of the country, using dynamite is called “shot firing” and frequently causes wells to collapse. In the case of dry ice, an increased upward pressure within the well can crack the wellhead allowing surface water to infiltrate and contaminate the well. The introduction of hydrofracturing eliminates these issues and is a much more controllable process.
How Hydrofracturing Works
The hydrofracturing process starts by removing all piping and the pump from the well. The procedure involves lowering one or two inflatable balloons into the well. These are called packers, and once down the well, they are inflated to seal off a section of the well. The packers are set a minimum of 20 -25 feet below the end of the well casing, typically a minimum of 60 feet underground in order to prevent a breakout of water pressure that can allow surface water into the well.
High-pressure water is pumped through the packer. Within the sealed section, the pressure rises as the formation resists flow. At some higher pressure, the pressure will suddenly drop indicating that the formation is accepting outside water and the flow resistance has decreased. Water is pumped into the formation at a rate of 25-60 gallons per minute for from 5 to 45 minutes. Up to 1600 gallons can be pumped in. Success is measured by a sudden drop in pressure, and the increased flow of water into the well. The packers may then be lowered further into the well, and the process repeated until the bottom of the well is reached. If there is no pressure drop, the hydrofracturing most likely failed.
When considering hydrofracturing for your well, there are a couple of considerations. First, this method only works on bedrock wells, that is wells that obtain their flow through fractures and cracks in the rock that intersect the wellbore. If your well is sand, clay or any other substance hydrofracturing is not possible.
When hydrofracturing a well it's important to consider the placement of any adjacent wells. If another well is located within 20 or 30 yards, there is some danger of negatively impacting the other well. As the distance increases, the risk diminishes.
When considering hydrofracturing, compare the costs involved in drilling a new well and the related infrastructure. Depending on the situation, it might be more cost-effective to drill and place a new well on the property. Speak with your well water professional for a more detailed comparison.
Geographic conditions can also affect the success rate of hydrofracturing. It has been found that different rock structures produced different results. Hydrofracturing was most successful in well composed of sandstone and siltstone sequences. Shale and volcanic sequences showed a lower percentage increase in production. No testing was done in a well dug through granite, which is the most common bedrock here in northern New England. Increased yields ranged from 35 to 1000% with the average improvement being around 200%.
The water used in hydrofracturing is chlorinated to prevent the introduction of bacteria into the well. After the procedure, the well must be pumped for a period of time in order to remove the water introduced during the process before the water is fit for consumption.
If you've noticed a drop in your well yield or water pressure, give the experts at Skillings and Sons a call. We're experts at various techniques for restoring water flow rates. Let us help you by providing you with all of the information, options, and costs associated with restoring your well.