Inventive Results Under Pressure

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 inch (51 millimeter) diameter and cut multiple layers of grouted casing in a single pass with a 55,000 PSI (3800 bar) abrasive waterjet.

Four layers of casing were jet cut six inches below the surface casing at 30.5 feet (9.3 meters). After removing this section the overcoring bit can be reduced, resulting in a successful retrieval of the entire string.
A DISTINCTIVE CHALLENGE
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 degrees Fahrenheit (60 degrees Celsius), minimizing the chance of ignition.

Very small casing sever and slot cut, 300 feet (91 meters) deep.

The hydraulic cylinders on the drill supporting the cutting head bled down while cutting causing this spiral effect.

Various used cutting heads, 4 inch (102 millimeter) OD to less than 2 inch (51 millimeter) OD.

Jet Edge pump 2000 feet (609.6 meters) below surface in a mine.
A POWERFUL PAIRING
The CenJet 90 is powered by a 55,000 PSI, 200 horsepower 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 inch (406 millimeter) thick steel, is deployed into the pipe or casing and cuts from the inside.  It can perform cuts up to 300 feet (91 meters) from the surface and can cut at any angle, horizontal, vertical and even overhead.
The CenJet 90 uses only 4 gallons (15 liters) of water and 1 pound (0.45 kilograms) 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.

A FLEXIBLE SOLUTION
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 over 4000 feet (1219 meters).  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 2100 feet (640 meters) underground and successfully cut hundreds of pipes and grouted casings at distances up to 300 feet (91 meters), many at a 70-degree angle.


Jet cutting using polymer enhanced circulation aids in carrying returns to the surface.

Three layers of casing cut at 300 feet (91 meters) deep recovered after overcoring.
Centura Oil’s worldwide services include waterjet well recompletion and production enhancement, well plug and abandonment, and mobile waterjet cutting. The company also sells its CenJet 90 systems under a licensing agreement. ■
About the Author

Nancy Lauseng is the marketing manager for Jet Edge. For more information about Jet Edge, visit www.jetedge.com or call 800.JET.EDGE (538.3343) or 763.497.8700. For more information about Centura Oil, visit www.centuraoil.com or call 952.545.6431.