Paper: Proper Treatment of Tubulars Key To Iron Control

Proper cleanout of millscale and other iron oxides from new tubular goods prior to their use reduces production damage by deposition (in the producing formation) of iron solids and iron in solution. Iron removed from new tubulars by stimulation fluids has caused formation damage and reduced production for many decades. This iron is available for removal from the walls of the casing and tubing by the action of stimulation acids and erosive proppants being pumped to stimulate the well. The sources of this iron are listed below. 1. Millscale (magnetite) is a thin layer of iron oxide found on the surface of tubulars. Millscale is deposited as a result of cooling the tubular steel after heating and extruding processes are done. 2. Iron oxides have many forms, but are basically rust. Although numerous iron scales are encountered in oilfield operations, and many are contacted by stimulation fluids, they are by-products of oil and gas production. Millscale and rust arrive on location with tubing and casing, and there is little doubt that the problem exists on most locations. This paper presents a method to "pickle" tubulars to help eliminate the source of many iron deposition problems.