气田集输系统安全性量化分析

Quantitative Analysis on the Security of the Gathering and Transportation System in Gas Fields

天然气属于易燃易爆物,天然气开采属于重点防火防爆行业,随着安全技术规范的全面发布,各气田普遍存在采气、集气工程建设项目安全距离不足的问题。针对川西气田典型案例,中国石化西南油气分公司开展了天然气泄漏扩散距离试验,以工况压力变化、壁厚余量、天然气流量、安全距离为风险分析评价因子,提出可与设计进行比较并可量化计算的安全系数Fs概念;同时结合天然气泄漏扩散距离,分别对地面管道正上方泄漏、侧向泄漏、埋地管线泄漏扩散范围进行比较,提出安全距离不足的风险判别方法和风险削减具体措施。经现场应用,该方法对工程项目安全距离不足问题的后期处置具有极大的参考价值。

Natural gas is a kind of flammable and explosive gas, and gas production belongs to the major industries that need to prevent fire and explosion. As the issue of safety technical norms, almost every gas field has the problems that the safe distance of gas production and gas gathering construction projects is short. The test study of diffusion distance for the gas leakage in Southwest Oil and Gas Branch begins with typical cases of gas fields in western Sichuan, with risk evaluation factors including pressure changes of working conditions, excess of wall thickness, rate of natural gas and safe distance, and the safety coefficient Fs that can be compared with design and calculated quantitatively is proposed. With the diffusion distance of gas leakage, the leakage diffusion scales of overhead leakage, lateral leakage and buried- pipeline leakage are compared respectively. The risk evaluation methods and risk reduction measures of safe distance lacking are put forward. Through the field application and analysis, it is concluded that the method has strong applied values in the after- treatment of safe distance lacking in construction projects.