Vol.16, No.5, 2020, pp.1031-1046, doi:10.32604/fdmp.2020.011145
A Multiphase Wellbore Flow Model for Sour Gas “Kicks”
  • Miao He1,2, Yihang Zhang1,*, Mingbiao Xu1,2,*, Jun Li3
1 Yangtze University, School of Petroleum Engineering, Wuhan, 430100, China
2 Hubei Cooperative Innovation Center of Unconventional Oil and Gas, Yangtze University, Wuhan, 430100, China
3 China University of Petroleum, Beijing, 102249, China
* Corresponding Authors: Yihang Zhang. Email: Luckyzhangyh@foxmail.com; Mingbiao Xu. Email: xumingbiao@yangtzeu.edu.cn
Received 22 April 2020; Accepted 24 August 2020; Issue published 09 October 2020
This study presents a new multiphase flow model with transient heat transfer and pressure coupling to simulate HTHP (high temperature and high pressure) sour gas “kicks” phenomena. The model is intended to support the estimation of wellbore temperature and pressure when sour gas kicks occur during drilling operation. The model considers sour gas solubility, phase transition and effects of temperature and pressure on the physical parameters of drilling fluid. Experimental data for a large-diameter pipe flow are used to validate the model. The results indicate that with fluid circulation, the annulus temperature with H2S kicks is the highest, followed by CO2, and CH4 is the lowest. The phase transition point of H2S is closer to wellhead compared with CO2, resulting in a faster expansion rate, which is more imperceptible and dangerous. With fluid circulation, the drilling fluid density and plastic viscosity both first decrease and then increase with the increase in the well depth. The bottom hole pressure when H2S kicks is greater than that for CO2 with the same amount of sour gas, and the pressure difference gradually increases with the increase of H2S/CO2 content. In addition, a parametric sensitivity analysis has been conducted to evaluate qualitatively and rank the influential factors affecting the bottom hole temperature and pressure.
Multiphase flow model; HTHP; sour gas kicks; phase transition
Cite This Article
He, M., Zhang, Y., Xu, M., Li, J. (2020). A Multiphase Wellbore Flow Model for Sour Gas “Kicks”. FDMP-Fluid Dynamics & Materials Processing, 16(5), 1031–1046.
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