边际效益天然气回收工艺技术研究及应用

Research and Application of Natural Gas Recovery Technique of Marginal Contribution

边际效益天然气主要包括陆地气田管网衔接不上、年久失修管线的气井和油田伴生气,以及海上人工岛产出的就地无法利用的小股量天然气。目前,对这些零散气的常规处理方式主要是点火炬燃烧或放空,这加剧了环境污染和资源浪费。通过对陆地和海上人工岛开展边际效益天然气回收技术研究,陆地采用CNG撬装技术,形成天然气回收、脱水、干燥、压缩、运输等配套服务的能力;通过改造陆地收气设备,建立人工岛移动式模块化天然气回收站,集天然气的增压、回收、净化、计量、卸载于一身,利用多台机组联机作业,大幅提高机组运行效率,简化人工岛伴生气的开发过程,降低回收成本,形成了完整的回收工艺技术。该技术经过推广应用,目前已形成年压缩天然气5200×104m3的技术能力,解决了收气项目中气源零散、低压难回收、回收效率低等技术难题,实现伴生气、零散气的全面回收。

Natural gas of marginal contribution consists of gas wells with the old pipeline in bad repair and no-joint with land gas field pipeline network and oilfield associated gas,and little natural gas unavailable for use in situ produced from offshore artificial island.Normal processing mode for these scattered gas is burning or relief mainly now,which will make more environment pollution and resource waste.Recovery technology of the natural gas with marginal contribution is researched on land and offshore artificial island.On land,CNG skid-mounted technology is applied for complete service of recovery,dehydration,aridity,compress,transportation of natural gas and so on.Movable and modular recovery station of the natural gas in man-made island is built through reforming the gettering unit on land,which can be used for boosting,recovering,purifying,measuring and unloading.On-line job by several machine trains may improve the operating efficiency of the machine trains.Simplified exploitation process of the associated gas on the man-made island may drop the recovery cost.Then a whole set of recovery technique may be formed.After the application and population of the technology,compressed natural gas has been up to 5200×104m3 per year.The technical puzzle of scattered gas source,difficult to recovery at low pressure and low efficiency of recovery may be solved and associated gas and scattered gas may be recovered completely.