Removing a Typical Iron Sulfide Scale The Scientific Approac

Iron sulfide scales vary in composition; this paper, in three parts, describes how a thorough analysis of the scale is necessary to optimize the chemical treatment and successfully remove the damage. The first part describes the different types and compositions of iron sulfide scale and the need for a tubing cleanout prior to an acidizing treatment. The second part describes the detailed analysis of the scale through the use of quantitative X-ray diffraction analysis and elemental analysis by energy dispersive X-ray. The third part of this paper presents scale removal treatment case histories.