Waterjetting has been around for decades. But prior to WellJet, it was not possible to generate sufficient downhole pressure to dislodge stubborn deposits. Some tenacious strains of iron bacteria and other minerals adhere to steel inside a well at up to 15,000 psi. It is necessary for any waterjet to exceed that pressure to truly make a difference.
On steel wells, WellJet operates at between 16,000 and 20,000 psi – more than enough to break up even the toughest bacterial deposits. Since the yield strength of mild and stainless steel ranges between 35,000 and 55,000 psi, and since the WellJet tool is in constant motion when under load, the risk of damaging casing or perforated areas is minimal.
An array of nozzles, mounted on a self-rotating head, emits this highly-pressurized water in a laminar flow, not only clearing obstructions inside the well screen, and opening perforations, but penetrating deep into the gravel pack – disintegrating the harmful deposits that are often the true cause of inadequate performance.
It is one thing to generate pressure at the surface – and quite another to deliver it 1,000 feet below ground. WellJet’s unique, patented delivery and internal nozzle design provide both the high downhole pressures and laminar flow needed to open up the perforations and stimulate the gravel pack.
The tool treats 100% of the perforated area and penetrates into the gravel pack where the real obstructions are frequently found.
Following WellJet treatment, the dislodged material is typically pulled from the gravel pack with a dual-swab surge block, and then evacuated from the bottom of the well via airlift, bailing or pump development.
The result is the world’s most effective method for water well rehabilitation.
WellJet is to ailing wells as penicillin was to sick humans in the 1940s. There is simply nothing else like it!
Three Steps for Success
WellJet recommends this three-step process for a successful well rehabilitation:
1) Analysis – well data, water sample + downhole video. Well data provides information about the well, formation and local hydrological conditions. The water sample tells us what kind of bacteria are present in the well. WellJet recommends SDK Laboratories, and can provide sample kits upon request. The downhole video tells us how badly the perforations are obstructed, and if any breaks or other damage are visible.
2) Open Pathways – the WellJet tool and delivery mechanism are lowered into the well to the bottom of the perforated area. The assembly is pressurized and retrieved. The jets clear obstructions from the entire perforation zone, and penetrate into the gravel pack and near-wellborn formation to break up deposits and open pathways for water flow.
3) Removal of Dislodged Material – WellJet recommends surging with a tightly-fitted dual-swab surge block to draw the dislodged material out of the gravel pack and into the bottom of the well, where it can be removed by airlift, bailer bucket or pump development.
