边际海上油田零散天然气回收技术研究

目前边际油田伴生天然气均采取气液分离后排火炬烧掉的处理方式,既污染环境,又浪费能源,为有效地回收边际海上油田零散天然气,有必要进行回收技术的研究。采用"井口平台—自航船—陆地"的生产模式,天然气的压缩、集气、周转在自航船上进行。油气在试采平台上分离后,天然气通过高压软管,进入压缩天然气(CNG)生产、运输系统(自航船)。在该系统中,天然气首先进入缓冲罐,经天然气压缩机增压至20 MPa,经脱水装置脱水后,进入系统的储气装置中,储气到额定的压力或气量后,自航船将天然气运至码头,卸气至天然气管网。与其他生产方式相比,CNG生产方式具有工艺简单、投资少、适应性强、经营风险小等优点。通过边际海上油田零散天然气的回收,可以合理利用资源,保护环境,增加天然气产量和商品率,提高油田的经济效益。

Research on Natural Gas Recovery Technology Used in Offshore Oil Fields

At present,most of associated natural gas is burned after separated from oil in offshore oil fields.This treatment mode will not only result in environmental pollution,but also waste a lot of energy.In order to recover such marginal natural gas effectively,it is essential to study natural gas recovery technology.Through using production mode of "wellhead platform—barge—land",all works in gas compression,gathering and revolution are carried out in barge.After separated from oil on production platform,natural gas is pipelined into compressed natural gas(CNG) production and transportation system(barge).In this system,natural gas is firstly led into a buffer tank and then pressurized to 20MPa by gas compressor.After dehydrated through dehydration unit,gas is led into gas storage tank finally.When storage tank reaches to a rated pressure or volume,it is transported by barge to dock and gas is led from storage tank into gas pipeline network.CNG production method has such advantages as more simple process,less investment,higher adaptability and less operation risk than other production methods.Through recovery,natural gas resource can be utilized rationally,environment can be protected efficiently and economic benefits of oilfield can be improved greatly.