Swaging can extend the well service life and improves water quality while minimizing maintenance costs and service downtime.
By Todd E. Kerry and Ahmad T. Hamdan, PE
Many areas across the United States, including ours in the Midwest, are seeing water levels in wells declining due to overpumping, drought, and lack of recharge.
This not only creates challenges in increasing horsepower (hp) requirements as pumps are set deeper, but it also provides unique challenges when it comes to relining a well. In traditional well relining, a smaller diameter well casing is installed, which in many instances prevents reinstallation of the old pumping equipment. In most cases, it requires redesigning a smaller system at reduced capacity.
As wells age, steel well casings and steel liners placed in wells begin to corrode and fail due to several reasons: improper construction, aggressive and corrosive water, stray current, jetting, and general corrosion.
A breach in the well casing can lead to undesirable water entering the well, sanding conditions, well contamination, or collapse of the native materials that the well casing was designed to hold back. If the situation is not remedied, then a total loss of your client’s asset could be the result.
In these cases, the traditional method of well repair would be either install a smaller casing—which reduces the well diameter (i.e., relining 12-inch well, based on state and local regulations for grouting requirements of annular space, requires 8-inch liner) and quite possibly requires you to downsize the pumping equipment—or drill a new well.
Both options tend to be costly to the client and relining an old well comes with inherent risks caused by “doglegs,” hole deviation, and potential hole collapse.
A New Way
Swaging is a newer technology which in many cases may provide a third option that can maintain well capacity and is less expensive than drilling a new well or relining an old well.
This is a technology we’ve come across as a cost-effective alternative that almost always allows you to retain the same-sized pumping equipment. One of our industry partners has been applying these technologies in the oilfield market for years throughout the world, and we’ve been able to adopt this technology in our market.
The oilfield industry typically leads the way in cutting-edge technology since they generally put more into research and development than the water well industry. As water well contractors, we have taken the approach to look outside our industry to integrate some of these technological advancements where applicable. We’ve gained a lot of our technologies by looking outside of the industry to solve complex problems.
Swaging involves pressing a stainless steel swage liner—with or without a neoprene backing—to the existing well casing or liner. It can provide a cost-effective and long-lasting solution for repairing damaged areas of well casings or screens.
In some cases, permitting may not be required since you are not “altering” the well construction. Swaging can be done with either specialized high-pressure swage packers or a hydraulic expandable swage. Both methods provide for a bond to the existing casing once properly prepped.
However, with the high-pressure packer, we have found it creates a more uniform bond than traditional hydraulic swaging. In our area, we find that older sand and gravel wells fail at the transition point of the casing to the screen. Since the swage can cover holes in the well casing, it can be a partial liner (minimum 3 feet) to overlap the well casing and screen interface, preventing sanding conditions.
The swage patch technology is only ¼-inch thick, meaning the patch will not interfere with installation of the pumping equipment. Therefore, well owners can keep their existing equipment and they do not have to lose capacity, as is often the case with the traditional method of relining a well with smaller diameter casing. Swaging will extend the well service life and improves water quality while minimizing maintenance costs and service downtime. Often swage liners can be installed within a day, depending on the length you are repairing.
Benefits of Well Swaging
In applications where relining a well that has had a breach in the casing—thus allowing undesirable water quality to enter the borehole—relining and proper grouting can stop this.
Installation of a swage patch over the holes with a neoprene backing, in our experience, has also stopped water intrusion. The swage patches have proven to hold up to external hydraulic water pressure. Another application of the swaging technology is that it can be used to repair well casing that may be folded over, preventing access to the lower borehole.
We’ve successfully swaged wells across the country, and the technology has been used throughout the well in various well diameters and depths. As with all well repairs, swaging must be tailored as a unique solution for each well application.
The photos show some examples of wells in which we’ve applied swaging technologies to repair problems. As seen in photos 1-4 , an intruding formation was obstructing installation and compromising well structure. After swaging, we had restored well structure, provided a long-lasting stainless steel liner, and maintained the same pumping equipment and capacity (photos 5-6).
In other instances, when an entire long-string casing of a well was deteriorating, we were able to swage the entire length of the long-string, preventing the need to drill a new well for the client. Swaging saved the customer both time and money, and they were able to place the well back into operation within a short period of time. Not to mention, they had effectively received an all-stainless steel well casing string for a low cost.
The application of swaging can also be used to reform and straighten casing that may be ovaled or deformed. As shown in photo 7, an 18-inch liner that was hung in the hole was damaged and folded over the top of the liner. This prevented installation of the pumping equipment to the required depth, as it would not allow the pump to pass by the obstruction. After swaging, we were able to reshape the top of the 18-inch liner (photo 8), removing the obstruction and allowing safe installation of the pumping equipment.
In addition, the packer technology can be used for fishing to recover lost pumps and tools. The first time we used this technology, it was to fish out a 500 hp submersible that fell off and dropped 1500 feet. As we discovered from the downhole video, there was 100 feet of 10-inch column pipe above the pumping equipment.
We were able to lower our inflatable swage packer into the 10-inch column pipe, where we inflated the packer catching the “fish.” We were successful in fishing out the pump on the first attempt. The client was impressed with the application, which led to several more swaging jobs for their wellfield.
Overall, swaging has enabled us to cost-effectively extend the service life of many deteriorating wells. Applying emerging technologies is the future of our industry. Thinking outside the traditional repair toolbox increases customer confidence in our professional ability as water well contractors and as an industry.
Todd E. Kerry is the central regional wells director for SUEZ Advanced Solutions and is a third-generation water well contractor. Kerry has more than 25 years of experience with innovative water well rehabilitation technologies, having helped develop several of the technologies that are currently being used throughout the United States. Kerry can be reached at email@example.com.
Ahmad T. Hamdan, PE, is a project manager for SUEZ Water Well Solutions Illinois Division LLC. Hamdan has spent his career thus far working on well and pump design, construction, and well rehabilitation/repairs. Hamdan is a licensed professional engineer in Illinois and can be reached at firstname.lastname@example.org.