TY - JOUR
TI - Transient flows in a wellbore during killing of an empty well
AU - Jiang Lin
AU - Wei Na
AU - Liu An-Qi
AU - Meng Ying-Feng
AU - Li Hai-Tao
AU - Sun Wan-Tong
AU - Zheng Li-Jun
AU - Fu Qiang
AU - Pang Wei-Xin
JN - Thermal Science
PY - 2019
VL - 23
IS - 4
SP - 2297
EP - 2306
PT - Article
AB - Failure to adequately equipping the wellhead with appropriate well control  equipment may result in a high pressure in the gas drilling when it reaches  a high-yield gas layer. This would require the execution of a well killing  operation to facilitate follow-up drilling and well completion. An empty  well of gas-phase brings implementation of a gas-liquid two-phase transient  flow, filling with killing mud. The operation may also entail coupling of  the transient seepage from the formation with the gas-liquid two-phase  transient flow through the wellbore. In this study, a mathematical model and  a numerical method for coupling the transient gas flow through the formation  with the gas-liquid two-phase transient flow in the wellbore were developed.  The numerical simulation results showed that successful killing of an empty  gas-drilled well required proper co-ordination of several key parameters  among which the wellhead backpressure is particularly crucial to the  operation. The findings of this study promise to facilitate the pro-cess  design and parameter optimization for the killing of empty gas-drilled  wells.