油气中汞的地球化学特征与科学意义

天然气中的汞主要来源于烃源岩，一般煤成气中汞含量高于油型气，煤成气中的高汞含量有煤系成因说和岩浆成因说等。异常高汞含量可能与深部断裂有关。天然气中‘汞主要以游离态存在且丰度较低；而凝析气和原油中汞的存在形式较为复杂，既有游离态汞，也有有机汞、无机汞和悬浮汞等。汞在油气中的含量很大程度上由其溶解度决定，油气混合物中，汞化学形式之间可能相互转化。由于汞的强吸附作用形成汞腐蚀，在油气运输、加工和利用过程中容易使设备不能正常工作，甚至会造成破坏性事故，因此，对于天然气中异常汞需要进行脱汞处理。图3表5参37

Mercury in oil and natural gas and its critical assessment

Abundance and forms of mercury in oil and gas have been increasingly paid attention to. There are mercury and its compounds in natural gas, condensate gas and crude oil. In natural gas, mercury exists exclusively in its elemental forms. Condensate gas and crude oil contain Hg of different forms, including elemental, organic, inorganic and suspended mercury. Hg stems from the hydrocarbon sources in natural gas, with Hg abundance higher in coal derived gas than in the oil derived gas. The abnormally high abundance of mercury in natural gas is related to the deep structure. Owing to its strong adsorption, Hg can easily form amalgams with a variety of metals causing problems in transportation pipeline or tank and other processing equipments, and even resulting in catastrophic events. So the abnormally high mercury must he removed from natural gas.