油气工业生物及化学硫化氢清除剂研究进展

Recent Research Progresses of Biological and Chemical H 2S Scavengers in the Oil and Gas Industry

在油气工业,硫化氢具有剧毒和强腐蚀性,会威胁人员安全,破坏设备和管道,必须及时清除。其中最常用的是化学清除剂,其与水/油/气相中的硫化氢结合,可转化为无毒、腐蚀性较弱、易于清除的物质。对于酸性气体,可以直接添加化学清除剂,也可以通过吸收或吸附等方法处理。此外,在钻井液等石油工程领域,亦广泛使用吸附型硫化氢清除剂。研究表明,活性纳米材料(NASS)和生物酶制剂是新型的高效硫化氢清除剂。NASS通过先进化学纳米技术工艺制造,无毒、无害,具有比表面积大、孔隙率高、形态独特、附加表面官能团等特性,且其反应活性高、化学选择性强,能够吸附各种有害化学物质。由于NASS的化学反应活性中心集中在更大的表面积上,且有更高的孔隙率,可将清除剂有效时间延长4~6倍。生物酶制剂是利用重组DNA和蛋白质表达技术开发的新颖的硫化氢清除剂。它是通过克隆嗜热菌的cDNA序列,并在合适载体中编码和表达,获得的一种功能蛋白质。实验室和现场试验表明,在盐水、原油和混合液中,生物酶清除剂能有效降低硫化氢,去除率为72%~90%。本文总结了油气工业中各种硫化氢清除技术,以及存在的问题和解决办法,指出应重点研发完全可再生的吸附清除剂技术,同时,环保高效的生物纳米技术将是重要发展方向。

It is well known that hydrogen sulfide(H_(2)S)is a highly toxic and corrosive chemical,imposes severe health threat on human beings,and may lead to equipment and pipelines failures.Every effort has been made to completely remove H_(2)S.The most suitable method is to employ some effective chemical scavengers,which react with H_(2)S dissolved into an aqueous/oil/gas phase and convert it into a nontoxic and less corrosive compound that can be easily removed.Instead of direct addition of a chemical scavenger,different approaches,including absorption and adsorption,are also adopted to eliminate H_(2)S from gas streams and during well-drilling processes under the actual reservoir conditions.The most recent research advancements are the applications of nano-active sulfide scavengers(NASS)and bio-enzyme scavengers(BES)for H_(2)S removal.NASS is a non-toxic,non-hazardous,non-dangerous chemical that is manufactured by using advanced chemical nanotechnology processes.It has unique molecular properties to enhance chemical reactivity and selectivity and can absorb a wide range of harmful chemicals.Due to its enhanced chemical reactivity and selectivity as well as exceptionally high porosity,NASS improves scavenger efficacy by 4—6 times.On the other hand,BES is generated by cloning the cDNA sequence from a thermophilic organism and an encoded protein in a suitable vector.Its efficacy is evaluated in the reservoir brine,crude oil and mixed reservoir fluids from laboratory-scale tests to pilot-scale tests with the reduction of H_(2)S concentration in the range of 72%—90%.This review presents the most recent research progresses and technical evaluations of a variety of chemical and biological H_(2)S scavengers that are currently used in the oil and gas industry.It also reveals some technical challenges and offers potential technical solutions.Future studies are required to design and formulate high-capacity sorbents with 100%re-generability.In addition,advanced studies are also required to research and develop environment-friendly and highly effective hydrogen sulfide scavengers through bio-nanotechnology.