Waste gas management on offshore platforms

在石油和天然气的生产和加工过程中，燃烧/排放是温室气体排放的最大单一来源之一。尽管燃烧仅贡献世界人为CO2排放的1%和CH 4排放的不到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GHG排放潜力减少10%。此外，燃烧产生大量的氮和硫有机物以及多环芳烃。事实上，由于单一平台的燃烧而进入海洋环境的多环芳烃可能在16-2000吨/年之间，这取决于燃烧的频率和气体的体积。偏远/海上平台上的燃烧来自与石油共同生产的天然气，其中经济性决定燃烧比回收和运输便宜（由于平台上的偏远和有限空间）。这种采出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设施。在许多监管制度中，回注受到限制，在某些深水威尔斯井中，回注往往会降低总体石油采收率。此外，处理和压缩用于再注入的气体所需的设备的成本可高达上部结构成本的12%，但不提供附加值。最终回收全部或部分天然气将最大限度地减少对环境的影响，因为不仅减少了向海洋环境的排放，而且天然气是一种“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的选择（通过管道、压缩天然气（CNG）、液化天然气（LNG）和气制液体（GTL））。然而，所有选项都需要在运输/储存之前进行某种平台气体处理，例如冷凝液/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和污染物来减少火炬气的体积/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.