Investigation of sulphide scale formation and inhibition in mixed H2S and CO2 - containing environments

摘要-与含硫化氢能源生产环境中腐蚀和结垢引起的硫化物有关的发展问题地热和油气系统的能源生产通常以气体和离子物种的复杂混合物为特征。卤水化学成分对这些物种有重大影响，特别是在使用碳钢的情况下，会对金属-流体界面的流动保证和与腐蚀相关的现象产生影响。一些关键的气体物种包括混合的硫化氢和/或二氧化碳。由于卤水化学中存在碱土和/或过渡阳离子，与流动保障相关的问题也越来越多。其中一些阳离子，如Ba2+、Ca2+、Zn2+、Pb2+等，除了影响金属界面的腐蚀特性外，还可能影响表面和体垢沉积动力学。溶解硫化物物种的存在和腐蚀过程中FeS的生成动力学可能会导致与过渡阳离子发生复杂的相互作用。这种相互作用会影响PbS和ZnS等硫化物物种的表面和体相沉积动力学及附着力。在FeS膜中加入阳离子可以显著改变FeS膜在金属界面的腐蚀性能。虽然已经尝试通过缓蚀剂和阻垢剂(顺/SIS)来缓解这种有害的界面和本体现象，但仍然缺乏对这些顺/SIS如何与腐蚀途径相互作用从而缓解这些界面现象的了解，尤其是：1)在存在各种形态的硫化铁(FeS)的复杂混合物的条件下；2)当FeS可能与竞争同一界面的过渡阳离子结合时。在锌和铅离子存在的情况下，在体液中形成的硫化锌和硫化铅沉积在表面的电位可能会引起腐蚀和流动保障问题。所有这些复杂的现象都没有得到充分的研究。基础研究表明，在简单的单相环境中FeS的形成与FeS的电子性质导致的点蚀损伤有关。在碱土和/或过渡阳离子存在的多相体系中形成的FeS的复杂性也可能改变FeS膜的电子性质，并可能影响点蚀特性的性质。虽然在金属-卤水界面上，显然迫切需要优化顺式化合物和/或SiS与复杂化学物质的硫化物垢相互作用的功能性质，但需要对这些界面进行初步的了解和准确的表征。

Summary - Developing Issues related to corrosion and scale induced sulfide in H2S-containing energy productions environmentsEnergy production from geothermal and oil and gas systems are usually characterized by a complex mixture of gaseous and ionic species. Brine chemistries have significant influences on these species, with consequential effects on flow assurance and corrosion related phenomena at the metal - fluid interface, especially with the use of carbon steel. Some of the key gaseous species includes mixed H2S and/or CO2. There have also been increasing flow assurance related concerns due to the presence of alkaline earth and/or transition cations present within brine chemistry. Some of these cations; Ba2+, Ca2+, Zn2+, Pb2+ etc have the potential to influence surface and bulk scale deposition kinetics in addition to corrosion characteristics of the metal interface. The presence of dissolved sulphide species and the kinetics of FeS formation from corrosion process is likely to induce a complex interaction with transition cations. Such interactions could influence the surface and bulk deposition kinetics and adhesion of sulphide species such as PbS and ZnS. Cations incorporated in FeS films could substantially transform the corrosion properties of FeS scales at the metal interface. While attempts have been made to mitigate such deleterious interfacial and bulk phenomena with corrosion and scale inhibitors (CIs and SIs), there is still a lack of understanding of how these CIs/SIs interact with corrosion pathways to mitigate these interfacial phenomena; particularly: 1) in conditions where a complex mixture of various Iron sulphide (FeS) morphologies exist; 2) when FeS is potentially incorporated with transition cations which are competing for the same interface. In the presence of Zn2+ and Pb2+ cations, the formation of ZnS and PbS in the bulk fluid which the potential to deposited on the surface are likely to induce corrosion and flow assurance issues. None of these complex phenomena have been fully investigated. Fundamental research has shown that the formation of FeS in simple single phase environments is linked to pitting corrosion damage as a result of the electronic properties of FeS. The complexity of FeS formed in the presence of alkaline earth and/or transition cations in multiphase systems may also transform the electronic properties of FeS scales and may influence the nature of pitting corrosion characteristics. While there is clearly an urgent need to optimize the functional properties of CIs and/or SIs in interaction with sulphide scales of complex chemistries at metal-brine interfaces, these interfaces need to be initially understood and accurately characterized.