Study on Cold Venting Characteristics of High-Sulfur Gas on Offshore Oil Platforms

Ying Liu; Zhen Shen; Shijia Zhang; Beibei Zheng; Shuai Liu

doi:10.6919/ICJE.202505_11(5).0015

Authors

Ying Liu
Zhen Shen
Shijia Zhang
Beibei Zheng
Shuai Liu

DOI:

https://doi.org/10.6919/ICJE.202505_11(5).0015

Keywords:

Cold Venting; PHAST; Toxic Gas; Dispersion Analysis; Maximum Downwind Distance.

Abstract

This study investigates the dispersion characteristics of cold venting gas containing hydrogen sulfide on an offshore platform in the western South China Sea using PHAST software. The maximum downwind distances of gas clouds under different atmospheric stabilities and venting rates were analyzed for both flammability and toxicity. For H2S toxicity analysis (minimum concentration threshold: 7 ppm), the maximum downwind distance initially increased and then decreased with rising wind speed. The optimal distance of 176.7 m occurred at a venting rate of 18 kg/s and wind speed of 4 m/s. This phenomenon arises from the dual effects of wind-driven horizontal transport and turbulence-induced dilution. For flammability analysis, the maximum downwind distance exhibited a continuous growth trend at a venting rate of 18 kg/s, reaching 52 m at 20 m/s wind speed. Here, horizontal transport dominated over dilution effects. These findings provide critical guidance for operational safety and accident prevention on offshore platforms.

Downloads

Download data is not yet available.

References

[1] Chen R Q. Determination of flare system design discharge rates for offshore platforms[J]. China Offshore Oil and Gas, 1997, 9(5): 4-7.

[2] Liu M S. Consequence simulation of H₂S leakage in Sichuan-Chongqing gas pipelines[D]. China University of Geosciences (Beijing), 2010.

[3] Mao H Z. Numerical simulation of natural gas leakage on offshore platforms[D]. Hebei University of Engineering, 2022. DOI:10.27104/d.cnki.ghbjy.2022.000735.

[4] Yuan J, Zhao D F, Meng Y F. Comparative analysis of gas dispersion models for engineering applications[J]. Petrochemical Safety and Environmental Technology, 2016, 32(01): 16-19.

[5] Huang W H, et al. Review of heavy gas leakage and dispersion models[J]. Zhejiang Chemical Industry, 2009, 40(07): 18-22.

[6] Cheng Y, et al. Hazards, origins, and mitigation of H₂S in offshore oilfields[J]. Petrochemical Technology, 2022, 29(12): 194-196.

[7] Tang P. Height optimization for emergency atmospheric discharges[J]. Petrochemical Safety and Environmental Technology, 2023, 39(02): 22-24.

[8] Yao J J, et al. Dispersion simulation of H₂S-containing flammable gas in enclosed ground flares[J]. Refining Technology and Engineering, 2016, 46(08): 16-19.

[9] Du J M. Risk assessment of LNG leakage and vapor cloud dispersion[D]. Harbin Institute of Technology, 2020. DOI:10.27061/d.cnki.ghgdu.2020.005253.