High-Pressure Washing Operations

The primary application of Weatherford’s MacJet^™ high-pressure downhole rotary jetting tool is the removal of scale precipitation restrictions in geothermal and hydrocarbon production tubing.

When this all-metal tool is used in conjunction with the rigid vane motor technology of the MacDrill^™ motor, flow input to the motor is expended on the wellbore through a number of high-pressure nozzles that are angled to facilitate well circulation. The resistance of the MacDrill motor to acidic fluids and solvents provides flexibility in selecting a pumping medium. The optimal differential pressure between the MacDrill motor and nozzle is 2,000 to 2,500 PSI (13,790 to 17, 237 kPa), which produces dynamic nozzle exit pressures in excess of 5,000 PSI (34,474 kPa) from the combination of high jet velocity and flow rate passing through a small nozzle.

Conventional wash nozzles rely solely on fluid velocity. Because it is deployed beneath a MacDrill motor, the MacJet tool also provides torque, which enables removal of hard-packed scale bridges that in many cases prevent the passage of standard wash nozzles.

Modular construction enables configuration of the MacJet tool for a variety of applications. For routine descaling operations, the MacJet tool is configured with two radially opposed jets; however, as many as four jets can be employed to remove softer scale restrictions such as asphaltine. A non-rotatable stabilizer can also be incorporated above the MacDrill motor to centralize the MacJet tool in the casing.