There are two types of pipeline cleaning programs available. One type is referred to as mechanical cleaning (the running of mechanical pigs dry) and second is Liquid Cleaning With Surfactant Base Cleaners.
Achieving greater solids removal from pipelines with fewer pig runs requires liquid cleaning, referred more commonly to as chemical cleaning. This type is becoming more popular in the industry . Liquid cleaning in tandem with mechanical pigs will remove a greater volume of debris with fewer runs.
Pipeline acid cleaners that dissolve solids could form harmful gases and be also detrimental to pipe-wall metals. Other liquid cleaners that dissolve iron sulfide MUST have water in them in order to facilitate the reaction. A popular product, aside from acids, is a product with an active ingredient called THPS, formulated with an ammonium ion or organic phosphonate to speedup the dissolution of iron compounds. 1 THPS is well known as a highly effective biocide for a variety of water treatment applications including oilfield down hole treating.