Above: Jet Edge pump 2,000 ft. below surface in a mine.
May 2014 - Centura Oil Inc., a Minnesota-based waterjet service contractor to the oil, gas and mining industries, has developed a unique downhole casing and pipe cutting system that can fit inside pipes as small as 2 in. ID (51 mm) and cut multiple layers of grouted casing in a single pass with a 55K PSI (3800 bar) abrasive waterjet.
Operable in hazardous environments, Centura Oil’s CenJet 90® casing and pipe cutting system is designed especially for oil, gas and mining applications, including plug and abandon operations. Its cutting process does not exceed 140°F (60°C), minimizing the chance of ignition.
The CenJet 90 is powered by a 55K PSI, 200hp Jet Edge waterjet intensifier pump and features a modified Jet Edge Permalign abrasivejet cutting head that is coupled to coiled steel tubing or conventional threaded rods. The system, which is capable of cutting 16 in. (406 mm) thick steel, is deployed into the pipe or casing and cuts from the inside. It can perform cuts up to 300 feet (91 m) from the surface and can cut at any angle, horizontal, vertical and even overhead. The CenJet 90 uses only four gallons (15 l) of water and one pound (.45 kg) of garnet abrasive per minute. Garnet is a natural stone that can normally be disposed of in a landfill. The effluent created by the waterjet cutting process is circulated to the surface using formation water, treated water in strata prone to swelling, or nitrogen for an explosion-proof environment. The returns and cuttings are handled in accordance with industry standards.
Centura Oil originally developed the CenJet 90 as an environmentally friendly downhole waterjet cutting system for stimulating oil and gas well production at depths of 4000+ feet (1219 m). It modified the system for casing and pipe cutting for a recently completed project at a uranium mine. During this 2.5 year project, Centura Oil staff worked 2,100 ft. (640 m) underground and successfully cut hundreds of pipes and grouted casings at distances up to 300 ft., many at a 70° angle.
Image above: Three layers of casing cut at 300 feet deep recovered after overcoring.
Below: Very small casing sever and slot cut, 300 feet deep.
