Black Powder Phenomenon in Gas Transmission Pipelines
Proceedings Publication Date
Black powder solids are a universal problem in sales gas transmission pipelines. These solid compounds can delay in-line inspection, erode control valves, and contaminate customer supply. Saudi Aramco has developed multiple initiatives to identify the black powder compound types, determine formation causes and identify removal processes. These initiatives consist of 1) using advanced mechanical cleaning tools, 2) performing basic research on identifying its compound types and formation mechanism, 3) pilot testing chemical cleaning methods, 4) planning to field test an inertial separator, and 5) revising company standards and construction practices. These initiatives can be further sub-categorized into short term and long term solutions. Before comprehensive solutions can be reached, the following questions need to be answered: What is the definition of a black powder? What level of black powder cleanliness is desired in the line? And what is the acceptable quantity of black powder that can be delivered to the customer? The type of black powder in the line can determine the chemical reactions and may determine the pipeline network type involved (e.g., upstream gathering field or transmission line). The level of black powder cleanliness desired in the line will dictate the degree of cleaning required to reach the specified cleanliness level (e.g., mechanical cleaning only versus chemical cleaning or filter installation). Finally, worldwide gas quality standards do not specify a solids amount. Simply declaring gas to be “commercially free” of solids is ambiguous and creates difficulties in designing proper facilities to meet this uncertain requirement. Answers to the three questions presented here will direct the impacted operating companies to a more focused and effective solution. Attendees will benefit from this presentation by understanding the impacts of the black powder solid, how black powder is formed, and the advantages and disadvantages of chosen solutions for remedy.