高含硫天然气净化厂安全监控技术——以普光气田为例

Safety monitoring and control technology of a high H_2S natural gas sweetening plant:A case study from the Puguang Gas Field,Sichuan Basin

四川盆地普光高含硫气田天然气净化厂年处理能力为120×108 m3,生产出的天然气为满足《天然气》(GB 17820—2012)一类气的优质商品天然气。如此大规模高压高含硫天然气净化过程,一旦泄漏或者工况失控,将会造成人员、设备以及环境的重特大危害。为此,针对此苛刻工况的安全控制技术难题,系统设计了多级安全仪表系统及各级联锁触发条件,优化了现场高危工段的液位、压力、流量等工艺控制点的监控、报警、联锁与动作方式,建立了一套稳定可靠的一体化安全联锁控制体系,关断有效率达100%;根据净化工艺过程HAZ0P分析与危害分级,合理地确定了泄漏监测布点方案,优化集成了有毒有害可燃气体泄漏监测、火灾报警、视频监控等多重安全系统,形成了净化过程的立体多元全方位监控与应急处置技术,泄漏监控率达100%,处置有效得当。该技术在普光气田天然气净化厂的应用,实现了高含硫高压天然气净化过程的安全、平稳、受控运行。

Gas produced in the Puguang Natural Gas Sweetening Plant with the annual capacity of 12 billion m3 is of good quality meeting the standard requirement in the National Code GB 17820-2012：Natural Gas.During the high pressure and high-H2S natural gas sweetening process on such a large scale,any failure or gas leakage will possibly result in major hazards or damages to working staff,equipments and the neighboring environment.Therefore,safety monitoring and control is a key issue in this case.In view of this,we designed a multi-level safety instrument system with all levels of interlocking trigger mechanism and optimized the monitoring,alarming,interlocking and action-taking methods especially at the high-risk points such as liquid level,pressure,flow rate,etc.Thus,we built a reliable and steady integrated interlocking safety control system with the shut-off rate of 100％.Additionally,we applied the Hazard and Operability Analysis （HAZOP） to classify the potential damage at levels and then reasonably determined the leakage monitoring points.On this basis,a multiple safety system was formed focusing on the toxic,harmful and flammable gases by optimizing and integrating all the measures like leakage monitoring,fire alarming,video surveillance,and so on.Meanwhile,three-dimensional multiple comprehensive monitoring and emergency response technologies were developed to ensure a hundred percent of leakage monitoring as well as proper and efficient disposals to be taken in the whole sweetening process.With the above safety monitoring and control technologies adopted,the Puguang Sweetening Plant is keeping on its smooth running with everything under control.