Relative Permeability Hysteresis Effects in the Near-Wellbore Region During Liquid Loading in Gas Wells

Zhang, H., Falcone, G. and Teodoriu, C. (2010) Relative Permeability Hysteresis Effects in the Near-Wellbore Region During Liquid Loading in Gas Wells. In: Latin American and Caribbean Petroleum Engineering Conference, Lima, Peru, 1-3 Dec 2010, ISBN 9781617821837 (doi: 10.2118/139062-MS)

Abstract

In oil and gas field operations, the dynamic interactions between reservoir and wellbore cannot be ignored, especially during transient flow in the near-wellbore region. A particular instance of transient flow in the near-wellbore region is the intermittent response of a reservoir that is typical of liquid loading in gas wells. Our previous numerical simulation study (Zhang et. al. 2009 and 2010) successfully captured the liquid backflow rates resulting from bottomhole pressure (BHP) oscillations typical of liquid loading, and emphasized their detrimental effect on gas production. This paper presents a numerical modeling effort to investigate the relative permeability hysteresis effects in the near-wellbore region during transient flow conditions for a synthetic, low permeability gas reservoir. Firstly, the previously validated "U-shaped?? pressure profile along the reservoir radius was generated with an increased BHP from a starting steady-state flowing configuration. This pressure profile can lead to reinjection of the liquid phase into the reservoir. The BHP was then let to decrease, with a corresponding temporary recovery in gas productivity. With subsequent BHP oscillations, the flow direction was allowed to switch back and forth, which could represent a typical liquid loading scenario. The Killough method was used to calculate the relative permeability hysteresis during the various imbibitions and drainage processes. The results reveal that the hysteresis effect is negligible at a high-frequency alternation of imbibition and drainage in the near-wellbore region, and may therefore not be significant in liquid loading problems.

• Item Type: Conference Proceedings
• Additional Information: SPE Latin American and Caribbean Petroleum Engineering Conference Proceedings. Volume 2, 2010, pages 974-987.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Falcone, Professor Gioia
• Authors: Zhang, H., Falcone, G., and Teodoriu, C.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• ISBN: 9781617821837