CFD Modelling and Simulation of Drilled
Cuttings Transport Efficiency in Horizontal
Annulus During Gas Drilling Process: Effect
of Gas Injection Method
Kaiyu Zhang 1(B) , Jirui Hou 1 , and Zhuojing Li 2,3
1 The Unconventional Oil and Gas Institute,
China University of Petroleum-Beijing, Beijing 102249, China
kaiyu.zhang@vip.163.com, houjirui@126.com
2 College of Petroleum Engineering,
China University of Petroleum-Beijing, Beijing 102249, China
lzj_1208@163.com
3 State Key Laboratory of Petroleum Resources and Prospecting,
China University of Petroleum-Beijing, Beijing 102249, China
Abstract. Gas drilling, such as the air or nitrogen drilling, can improve the drilling
efficiency and effectively protect the oil and gas reservoir from the lost circulation
during the drilling process. However, a major disadvantage of the gas drilling is the
severe deposition of the drilled cuttings, especially in the horizontal gas drilling,
which mainly caused by the poor transport capacity of the gas phase due to its low
density and viscosity. Generally, the solution is increasing the gas injection rate,
but it will lead to a higher cost and may cause ice-balling of the drill bit. In this
paper, a pulsed gas injection method is proposed to overcome the shortcoming,
leading to cost reduction and efficiency increase. The Eulerian-Eulerian two-fluid
approach with the kinetic theory of granular flow is employed to simulate the gassolid two-phase flow in a 3D eccentric horizontal annulus using CFD modelling.
The RNG k-ε turbulence model is adopted to describe the turbulence behavior of
the gas phase. The effects of various gas injection methods on the gas inlet velocity,
pressure drop, cuttings volume fraction, granular temperature, turbulence kinetic
energy, and turbulence dissipation rate are systematically investigated. The results
show that almost no stationary cuttings bed is formed in the annulus under the
pulsed gas injection condition. The cuttings particles are conveyed out within the
wave-like moving cuttings bed. Compared with the constant-rate gas injection
method, the pulsed gas injection method provides a much better cuttings transport
efficiency at the identical condition of gas injection volume.
Keywords: Pulsed gas injection · Cuttings transport efficiency · Gas-solid
two-phase flow
1 Introduction
Since the first air drilling operation was conducted in the early 1860s, the gas drilling has
gradually been a popular alternative technique for drilling a well. Briefly, gas drilling,
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. N. Atluri and I. Vušanovi´ c (Eds.): ICCES 2020, MMS 97, pp. 199–211, 2021.
https://doi.org/10.1007/978-3-030-64690-5_19
Cuttings Transport Efficiency in Horizontal
Annulus During Gas Drilling Process: Effect
of Gas Injection Method
Kaiyu Zhang 1(B) , Jirui Hou 1 , and Zhuojing Li 2,3
1 The Unconventional Oil and Gas Institute,
China University of Petroleum-Beijing, Beijing 102249, China
kaiyu.zhang@vip.163.com, houjirui@126.com
2 College of Petroleum Engineering,
China University of Petroleum-Beijing, Beijing 102249, China
lzj_1208@163.com
3 State Key Laboratory of Petroleum Resources and Prospecting,
China University of Petroleum-Beijing, Beijing 102249, China
Abstract. Gas drilling, such as the air or nitrogen drilling, can improve the drilling
efficiency and effectively protect the oil and gas reservoir from the lost circulation
during the drilling process. However, a major disadvantage of the gas drilling is the
severe deposition of the drilled cuttings, especially in the horizontal gas drilling,
which mainly caused by the poor transport capacity of the gas phase due to its low
density and viscosity. Generally, the solution is increasing the gas injection rate,
but it will lead to a higher cost and may cause ice-balling of the drill bit. In this
paper, a pulsed gas injection method is proposed to overcome the shortcoming,
leading to cost reduction and efficiency increase. The Eulerian-Eulerian two-fluid
approach with the kinetic theory of granular flow is employed to simulate the gassolid two-phase flow in a 3D eccentric horizontal annulus using CFD modelling.
The RNG k-ε turbulence model is adopted to describe the turbulence behavior of
the gas phase. The effects of various gas injection methods on the gas inlet velocity,
pressure drop, cuttings volume fraction, granular temperature, turbulence kinetic
energy, and turbulence dissipation rate are systematically investigated. The results
show that almost no stationary cuttings bed is formed in the annulus under the
pulsed gas injection condition. The cuttings particles are conveyed out within the
wave-like moving cuttings bed. Compared with the constant-rate gas injection
method, the pulsed gas injection method provides a much better cuttings transport
efficiency at the identical condition of gas injection volume.
Keywords: Pulsed gas injection · Cuttings transport efficiency · Gas-solid
two-phase flow
1 Introduction
Since the first air drilling operation was conducted in the early 1860s, the gas drilling has
gradually been a popular alternative technique for drilling a well. Briefly, gas drilling,
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. N. Atluri and I. Vušanovi´ c (Eds.): ICCES 2020, MMS 97, pp. 199–211, 2021.
https://doi.org/10.1007/978-3-030-64690-5_19