Investigation of the Effect of Tubing Dimensions on Oil Well Production and Flow Assurance: A PIPESIM Simulation Study

The design of the production tubing string is a primary factor controlling pressure drop, liquid holdup, and flow patterns in oil wells. This study utilizes the PIPESIM steady-state multiphase flow simulator to conduct a comprehensive sensitivity analysis on the effects of tubing length (۴۷۲۷ ft, ۸۰۲۱ ft, and ۹۱۹۶ ft) and internal diameter (۲.۷۵, ۲.۹۹۲, and ۳.۰۶۸ inches) on well productivity. Using a calibrated Black Oil fluid model representing a well in southwest Iran, our simulations confirmed a strong correlation between increased tubing diameter and reduced frictional pressure losses, resulting in lower liquid holdup and higher production rates. However, the analysis critically highlights the economic principle of diminishing returns, where the incremental production benefit shrinks significantly at larger diameters. For a ۹۱۹۶ ft tubing, upsizing from ۲.۹۹۲ to ۳.۰۶۸ inches increased production by only ~۳%, a marginal gain that may not justify the higher completion cost. The key finding is that optimal tubing selection requires a balanced techno-economic analysis, weighing the value of marginal production gains against associated capital expenditures. This research provides engineers with a quantitative basis for making informed design choices that maximize economic value rather than just theoretical flow rates.

کلیدواژه ها:

Tubing size ، Production rate ، Pressure drop ، Liquid holdup ، Flow pattern