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

总结--在含H2S的能源生产环境中与腐蚀和结垢引起的硫化物相关的发展中问题地热和油气系统的能源生产通常以气体和离子物质的复杂混合物为特征。盐水化学对这些物质具有显著影响，从而对金属-流体界面处的流动保证和腐蚀相关现象产生影响，特别是在使用碳钢的情况下。一些关键的气体物质包括混合的H2S和/或CO2。由于盐水化学中存在碱土金属和/或过渡阳离子，也存在越来越多的流动保证相关问题。其中一些阳离子; Ba ~（2+）、Ca ~（2+）、Zn ~（2+）、Pb ~（2+）等离子除了影响金属界面的腐蚀特性外，还可能影响表面和体尺度的沉积动力学。溶解的硫化物物种的存在下，从腐蚀过程中形成的FeS的动力学可能会引起一个复杂的相互作用与过渡阳离子。这种相互作用可能会影响表面和本体沉积动力学和硫化物物种，如PbS和ZnS的粘附。掺入FeS膜中的阳离子可以显著改变FeS膜在金属界面处的腐蚀性能。虽然已经尝试用腐蚀和结垢抑制剂来减轻这种有害的界面和本体现象（CI和SI），仍然缺乏对这些CI/SI如何与腐蚀途径相互作用以减轻这些界面现象的理解;特别是：1）在存在各种硫化铁（FeS）形态的复杂混合物的条件下; 2）当FeS潜在地与竞争相同界面的过渡阳离子结合时。在存在Zn 2+和Pb 2+阳离子的情况下，在本体流体中形成ZnS和PbS，其可能沉积在表面上，这可能引起腐蚀和流动保证问题。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形成FeS与点蚀损伤有关，这是由于FeS的电子性质。在多相系统中碱土金属和/或过渡阳离子的存在下形成的FeS的复杂性也可能改变FeS垢的电子性质，并可能影响点蚀特性的性质。虽然显然迫切需要优化CI和/或SI在金属-盐水界面处与复杂化学物质的硫化物垢相互作用的功能性质，但这些界面需要最初理解和准确表征。

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.