Flow assurance is an engineering analysis process to assure hydrocarbon fluids are transmitted economically from the reservoir to the end user over the life of a project in any environment.
The term "Flow Assurance" was first used by Petrobras in the early 1990s, it originally only covered the thermal hydraulics and production chemistry issues encountered during oil and gas production. While the term is relatively new, the problems related with flow assurance have been a critical issue in the oil/gas industry from very early days. Hydrates were observed causing blockages in gas pipelines as early as the 1930s.
Another problem is slugging and liquid handling. The occurrence of slug flow in a transportation pipeline and a gathering system can cause many problems in design and operation processes, which include kinetic force on fittings and vessels, pressure cycling, control instability and inadequate phase separation. Slugging affects greatly the design of receiving facilities. In gas condensate systems, larger lines result in more liquid being retained in the pipeline at low rates. When the flow rate is increased, much of the liquid can be swept out, potentially overwhelming the liquid handling capability of the receiving facilities. The facilities can be flooded and damaged if the slugs larger than the slug catcher capacity. Therefore, quantifying the slug size, frequency and velocity is necessary prior to equipment design.