Ashley Bernard Johnson

An Abrasive Jetting Scale Removal System

We describe a novel abrasive jet cleaning system for removing scale from production tubulars. By careful selection of abrasives we can remove the mineral growth without damage to the steel. We also describe a field test for the system where it ran back to back with mills, an impact hammer and water jetting tools. The abrasive selection is a critical parameter in the performance of the system. Pure water jets will clean certain soft scales, although they tend to lift the growth off the tubular in large pieces which are not conducive to good hole cleaning. Some water jetting systems use acid to soften the scale, but this limits the applicability of the system. The use of sand as an abrasive is common for certain jetting applications, however this can damage the tubing of jewellery. We discuss the selection of the Sterling Beads to clean the scale without damaging the steel. We also describe the first field test of the system, where it was run in a well to clean Aragonite scale from 2 3/8 in. tubing. Numerous milling and tools had been tried, but all had failed to clean the tubing, and most had been destroyed. As had other mechanical and water jetting systems. The new abrasive jetting system using Sterling Beads was run and cleaned the tubing at a high penetration rate with minimal damage to the plastic coating which had originally coated the production tubing and no damage to the steel itself.