The sour gas produced from the offshore Point Arguello oil field will be transported through a pipeline consisting of offshore and onshore sections terminating at an onshore processing plant. Accurate prediction of the complex flow behavior of the fluid in both pipeline sections is essential for proper operation of the pipeline. The objective of this paper is to analyze and provide engineering solutions for the operational problems occurring during the different production phases of the field.
It was found that the Point Arguello pipeline would exhibit different flow behaviors, depending upon the input flow rates. A simplified, flow pattern dependent, transient two-phase flow simulator was used to predict this complex flow behavior. For low input flow rates the offshore pipeline section would operate under slug flow conditions, with liquid accumulating in the line, and frequent pigging being required. For high input flow rates, the offshore pipeline section would operate under stratified flow, resulting in less liquid accumulation and liquid being transported into the onshore section. These different operational modes play an important role in leak detection analysis.
The rigorous analysis of the complex flow behavior presented in this paper provides solutions for proper operation of offshore wet gas pipelines. This includes solutions for liquid accumulation, pigging frequency, and pressure fluctuations for leak detection.