Analytical assessment of horizontal well efficiency with reference to improved oil recovery of the South-East Dragon oil field southern offshore of Vietnam

Nowadays, improved oil recovery (IOR) becomes much needed in field development planning, and is one of the main concerns for engineers in many reservoir management projects. Among IOR methods, horizontal wells have been widely applied in the world, and proved to be a promising technique. However, prudence is required in order to ensure maximum economic benefit in applying the technology. s study, the applicability of horizontal well in the South-East Dragon field, which is a small fractured basement reservoir in the southern offshore of Vietnam, was assessed. An overview of the SE Dragon reservoir characteristics was provided. The potential performance of horizontal wells was analyzed using analytical approaches, and the performance was compared with that predicted for vertical wells. Sensitivity study was conducted to investigate the effect of horizontal well length on well performance. The results of this study showed that, instead of a 350 m vertical well, drilling of a 400 m horizontal well at the same location could produce an additional 3,658,166 bbl of oil after 20 years. The efficiency increased proportionally with horizontal well length. The actual production rate can however be lower than predicted because of the assumptions used in the analysis.