含硫气井定量风险分析方法

Quantitative Risk Assessment for Natural Gas Well with Hydrogen Sulfide

随中国经济对石油天然气能源依赖程度的加深,大力开发含硫化氢气田成为重要任务,而定量评价含硫气井的风险显得更加必要和迫切。提出了含硫气井井喷事故硫化氢泄漏扩散过程中个人风险定量计算方法,根据相关统计资料,提出了井喷事故概率的参考值,将该方法应用于川渝地区某含硫气井,获取了该井周边区域个人风险等值线,并与可接受风险水平进行对比分析。结果表明,由于地形条件的影响,在气井周边不同方向的个人风险水平差异很大,可接受风险水平上限值等值线距井口的距离在不同方位上相差可达1000m,在对气井进行定量风险分析时必须充分加以考虑。该方法可为油气田开发企业、安全监管部门对含硫气井开发过程实施定量风险评价和管理提供有效技术手段,并为应急计划区的划分及边界确定提供参考。

With the heavy dependence of domestic economy on oil and gas, the exploitation of natural gas fields with hydrogen sulfide is an argent project in China. The quantitative risk assessment for natural gas wells with hydrogen sulfide is a necessary and impending requirement. A quantitative calculation method for an individual risk for leakage and dispersion process of hydrogen sulfide in blowout of gas wells is proposed in this paper. Based on the statistical analysis of data in literature, the probability of blowout incident is brought forward for reference. The method is applied to a typical gas well in Sichuan and Chongqing district as a practical example. The contour curves of individual risks in the area around the well are obtained, and compared with the acceptable level of the individual risks. The results show that the topographic conditions of the gas well greatly influence the calculation results of the individual risks, the distance between the upper limit isoline of acceptable risk and the well in different directions can reach 1000m. So it must be fully considered when performing the quantitative risk assessment of gas wells. This method offers an effective technical measure for administration departments and enterprises to conduct quantitative risk assessments and risk managements during the exploitation process of natural gas fields with hydrogen sulfide. The method can be used in dividing emergency planning zones and deciding the boundary for natural gas wells with hydrogen sulfide.