Waste gas management on offshore platforms

石油和天然气生产和加工过程中温室气体排放的最大单一来源之一是燃烧/排放。虽然燃烧只占世界人为二氧化碳的1%，占甲烷排放量的不到4%，但《京都议定书》已经确定，减少/消除燃烧相当于工业化国家温室气体排放潜力减少10%。此外，耀斑还排放大量氮、硫有机物和多环芳烃(PAH)。事实上，根据燃烧频率和气体体积的不同，单一平台产生的多环芳烃对海洋环境的输入可能从16-2000吨/年不等。远程/海上平台上的燃烧来自与石油联合生产的天然气，经济上决定了燃烧比回收和运输成本更低(由于平台的偏远和有限的空间)。这些产生的气体被称为搁浅气体，通常被燃烧、重新注入或用于平台上的公用事业。回注受到许多监管制度的限制，在一些深水油井中，回注往往会降低石油的整体采收率。此外，处理和压缩天然气以便重新注入所需的设备成本可能高达上部成本的12%，但不能提供任何附加值。最终，全部或部分天然气的回收将把对环境的影响降至最低，这不仅是因为减少了对海洋环境的排放，而且因为天然气是一种“更清洁”的化石燃料来源。许多因素决定了回收部分气流或全部气流(通过管道、压缩天然气(CNG)、液化天然气(LNG)和天然气转化为液体(GTL))的选择。然而，所有方案在运输/储存之前都需要某种类型的平台气体处理，例如凝析油/NGL去除、露点控制和/或污染物去除。这项工作的重点是通过去除NGL和污染物来降低燃烧气体的体积/毒性。

One of the single largest sources of greenhouse gas emissions in the production and processing of oil and gas is a result of flaring/venting. While flaring only contributes 1% of the world's anthropogenic CO2 and less than 4% of CH4 emissions, the Kyoto protocol has identified that reducing/eliminating flaring is equivalent to a 10% reduction in GHG emissions potential for industrialized countries. In addition, emissions of nitrogen and sulphur organics and polycyclic aromatic hydrocarbons (PAH) are produced from flares in significant amounts. In fact, the input into the marine environment of PAHs due to flaring from a single platform could vary from 16-2000 tonnes/yr depending on the frequency of flaring and volumes of gas. Flaring on remote/offshore platforms derives from gas co-produced with oil where economics dictate flaring is less expensive than recovery and transport (due to remoteness and limited space on the platform). This produced gas is referred to as stranded and is typically flared, re-injected or used for utilities on the platform. Re-injection is restricted in many regulatory regimes and in some deepwater wells the re-injection tended to degrade the overall oil recovery. Further, the equipment required to treat and compress the gas for re-injection can cost up to 12% of the topsides cost but provide no added value. Ultimately recovery of the all or part of the natural gas would minimize environmental impacts by not only decreasing emissions into the marine environment but also as natural gas represents a "cleaner" source of fossil fuel. A number of factors determine the option of either recovering part of the gas stream or all of the gas stream (via pipeline, Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), and Gas to Liquids (GTL)). However all options require some sort of platform gas treatment prior to transportation/storage such as condensate/NGL removal, dewpoint control, and/or contaminant removal. This focus of this work is to decrease the volume/toxicity of flared gas by removal of NGLs and contaminants.