Well swaging has modernized well repair

Swaging is a cold forging process in which the dimensions of metal are altered using dies to produce a different shape. In the past casing swaging was done by driving a hardened steel wedge, called a drive swage, through bent or mangled well casing. Today expandable swage tools are used to push casing back out to its intended shape and diameter. The best swages use double acting hydraulic cylinders with motor, controls, and all valves at the surface. This gives the operator complete control over up to two hundred tons of force used to forge out old casing and to forge in new steel. The advantage of a surface operated two way cylinder valve is the swage can work as a sizer, scraper or fishing tool that can never become hydraulicly stuck open. Some well repair is done using inflatable packer as swages. These swages don’t use harden dies or leverage and can’t push out tough breaks or mangled steel. They are mainly used to stretch out liners to stop deteriorated well casing from leaking in unwanted water. In well swaging it is important to understand patches are not liners. Patches are used to repair casing and liners are used to block or filter water entry.

Well Patching

Patches are sections of pipe made to the well diameter and are unfolded into a well’s existing casing to make a repair. Patches are used to stop unwanted water intrusion, sand entry or to connect separated broken casing. A well patch reduces the well size by about ¼-inch depending on the thickness of the patch and how much pressure is applied during swaging. Patches restores a well’s casing back to its proper size and dimensions without the need to reduce pump size or pumping rate. The patch is a piece of steel with folds or wedges in it. The patch is pressed out into the well’s casing using a hydraulic swage to form a round tight-fitting inside brace. The reason a hydraulic swage is used is it has up to 10,000 pounds per square inch of pressure to force a patch into the well casing, making the repaired area as strong or stronger than the original casing. The “rule of thumb for patch strength” is it takes the same amount of pressure to collapse a patch back in as it does to push it out. Watertight seals are made by matching the exact outside circumference of the patch to a well’s casing inside diameter and/or by adding rubber or neoprene to the patch.

Well swaging can be done off a crane or pump hoist making the difficult repair job accessible.

Well Lining

Well lining is long sections of patches or liners pressed out against old casing to give a well a coat or inner jacket of new steel. An inflatable swage packer does it with thin-wall stainless steel because stainless steel is more flexible and can be easily stretched out. Rubber backing is often use with stainless steel to prevent dissimilarity metal contact when this is a concern. A hydraulic swage is slower because it pushes out a smaller area with each push, but it can use thicker sleeves or patches for a stronger more permanent solution. The advantage of using patches is they can be made to the well’s exact inside diameter and don’t lose strength from thinning or stretching. Welding the sleeves or patches together before installing them down the well prevents water entry at connected joints and lessens the need for rubber backing to prevent water leaking. If the well casing is extremely deteriorated patches should be used because patches can be made thicker and are always stronger.

The City of Farmersville Ca main production well had missing and deteriorated casing in top 25 feet a 30 foot patch was lowered and swaged into place

Well Liners

Well liners are different from patching or lining. Unlike patches or liners pressed out against casing well liners have the full water table pressure pushing at them. This means a well liner is stand-alone pipe and should conform to pipe thickness and strength standards for water wells. Well liners are used to extend a well’s depth, replace long sections of failed casing, filter out sand or block unwanted water from traveling up or down inside the well. The consideration in installing a liner is it reduces a well’s diameter; often a pump needs to be downsize and the pumping rate lowered to conform to acceptable water entrance velocities. The rule of thumb here is the higher the water table is above the liner the stronger the liner needs to be to keep from collapsing. The best way to install a well liner is to keep it as short as possible and swage in a sealing boot at the top or bottom leaving the rest of the well as is.

The City of Farmersville Ca main production well had missing and deteriorated casing in top 25 feet a 30 foot patch was lowered and swaged into place.

Fishing and installing liners with a swage

A hydraulic swage can double as a hydraulic liner hanger or fishing spear. The swage can latch on to pipe, pump column, tail pipe or sand separator and lift it from the well. It can also be used to lower a long liner or section of sand screen down a well. Traditional fishing spears and liner hangers need to be the perfect size to grab onto something and are difficult to release. A hydraulic swage opens up and builds pressure when it encounters the object to be lifted or lowered. It is the equivalent of welding a liner or fish to the tool and being able to easily release it when wanted..

Headman Drilling in Sacramento California was hired to remove a send separator that came off a pump and to remove the sand that was in the bottom of the well. The hydraulic swage made an easy job of removing a 10-inch sand separator from a 12-inch well.

The most frequently asked questions about swaging are:

What is the difference from a hydraulic swage and a swage packer?

The answer is leverage. Most hydraulic pumps can develop 10,000 psi and that pressure is multiplied by the number of square inches of the piston inside the swage cylinder. Packers have no piston, and the pump pressure is the push pressure. A large swage can safely develop 200 tons of pressure a packer would burst at about ¼ of that.

What is the difference between a well patch and liner?

Liners are stand-alone pipe that require their own strength to keep from collapsing. They are considered new construction in an existing well and should conform to well construction standards. Patches expand out against existing casing making the casing thicker and stronger. In most cases they are not altering the designed construction only adding more metal to bring existing casing back to standards. Patches are normally made thin for room but need to be strong enough to seal and hold out damage casing. There are times, such as when sealing large sections of perforations that patches need to be made thicker or doubled up to hold against water pumping pressure.

I have a hole or break in my well; it’s not pumping sand. Do I need to fix it?

The answer is you should. A breach in the casing keeps growing and is a ticking time bomb and can fill the well with sand at any time. This usually happens when the well is struggling to make water when you need it the most.

Won’t bad water or sand find it way around a well patch?

The answer is no. Water flows into a well horizontally from an aquifer, and just like blank casing keeps brackish water out, a casing patch stops flow from that zone. Contaminates can migrate up or down a gravel or filter pack. If this is the case a patch along with pressure grouting can seal off the migrating contaminants.

Can PVC wells be patched?

The answer is yes, any type of well casing can be repaired by a skilled swage operator. Well casings smaller than 6 inch are not good candidates because the patch reduces well size, and a pump can’t be place inside the well.

Is hydraulic oil safe to use?

Yes, but care should be taken. Some swages still dump water or fluid into a well to release pressure. Today the best swages use hydraulic double acting cylinders; this means they are closed systems, and when operated the oil moves up and down inside hydraulic lines. Hydraulic lines use braided stainless steel and are very strong. Hydraulic oil is not considered very hazardous and floats on water just like the oil used in a turbine pump. If a line were to break the spill is minimal and can be easily cleaned up by using a skimmer pump or oil bailer.

Need a well swaged
Call or contact us:

Swaging is fast easy effective  well repair.

Contact us