Introduction
Major problems are generally encountered when acidizing sour oil or gas wells. Sulfide scales or minerals presented in the formation or production tubular will react with acids to release H₂S, which is corrosive and hazardous. H₂S scavenger is generally required while acidizing sour gas or oil wells to inhibit corrosion and resolve safety concerns.
H₂S scavenger is used in acid fluids to control corrosion effect of H₂S that may present due to acid reaction with sulfide scales or formation minerals. H₂S scavenger will remove H₂S in acids by reaction to form non-corrosive or non-hazardous compounds.

Physical Properties and Hazards

Chemical Properties and Application
Sulfide minerals present in the formation or sulfide scales deposited at tubulars will react with acids while acidizing sour gas or oil wells. H₂S scavenger is a mixture of organic compound that can be easily dispersed in acids, brines, or solvents. The active ingredients in H₂S scavenger will react with H2S to form stable and non-corrosive compounds.
H₂S scavenger is effective in most acid systems such as HCl and mud acids. It can be used at temperature up to 350 degF and for protection time up to 24 hours.
The loading of H₂S scavenger depends on formation mineralogical property and scaling conditions of wellbore. The acidizing design must also include procedures to flush away produced gas from tubing or casing before acid comes in contact with formation or scales.
H₂S scavenger is compatible with most additives in acids. It is also readily biodegradable and presents lower toxicity to organisms than other H₂S scavengers.