Surface treatment of downhole motor- the successful solution to the corrosion in saturated brine

1. Successfully solved the corrosion problem in saturated brine.

Processing method comparison:

a. Chromium plating is the most widely used method at present. 90% of domestic petroleum customers use this method, which has a short service life and low price. The biggest problem of electroplating is environmental pollution, and electroplating cannot work in saturated brine.

b. Spraying WC, customers basically require WC coating on drilling tools, in addition to strong wear resistance, it is also resistant to hydrogen sulfide, salt water and other corrosion. The disadvantage is high cost, and the advantage is long service life. The drilling tool has been used for more than 600 hours and is still intact, and can be used normally in saturated brine.

2. Coating Technology Solve Saturated Salt Water Corrosion Problem

a. Coating technology (only introduces the successful solution to the corrosion problem in saturated salt water)

Slurry pumps have prominent helical areas called “lobes” with 4, 5 or 7 lobes at the top called crests (or crests). The crests form the “main diameter”. The main size varies from 4.0 to 6.5 inches, which becomes the size range of the motor.

The lowest point is called the trough (or trough), and the trough forms the “minimum diameter”. The standard distance from lobe to trough is about ¼-inch (6.35mm). There are very strict requirements for the “wave top” in the middle of the motor and the “jump” between the two ends. As a standard, the “runout” value should be less than 0.010″ (0.254 mm). Anything more and the pump’s rubber hose will quickly be destroyed when the motor spins during operation.

surface preparation

a. For spray coating, grit blasting is not required. The surface needs to be cleaned with hand tools only when necessary or degreasing is required. Spraying can still be used as a backup, when it is necessary to quickly clean the surface or partially repair the sprayed coating.