采油用高温缓蚀阻垢剂的研究及应用

目的通过化学防腐技术,解决油田生产中高温油井腐蚀结垢影响油田正常生产的难题。方法进行挂片失重实验和容量分析实验,开展现场水质分析和垢样分析,通过正交实验研究不同种类缓蚀阻垢剂在不同添加量、不同温度下对缓蚀效率、阻垢效率的影响。结果在明确油井腐蚀结垢原因的基础上,有针对性地研制出了以咪唑啉衍生物和有机膦酸盐等为主,以耐高温的氟碳咪唑啉为辅的HZG系列缓蚀阻垢剂。其缓蚀阻垢效果较好,缓蚀率达90%以上,阻垢率达95%以上,有效缓解了高温油藏(大于100℃)油井井筒腐蚀、结垢的问题。经10口井现场应用,铁离子下降率平均达到82%,钙离子浓度明显上升,平均检泵周期延长了2.2倍。结论氟碳咪唑啉的加入有效提高了缓蚀阻垢剂的耐温性。HZG系列缓蚀阻垢剂用于现场的缓蚀阻垢效果较好,解决了高温油井腐蚀结垢的难题。     

The Link Between the Corrosion and calcium carbonate scaling susceptibilities of heat transfer surfaces

The nucleation of CaCO₃ scales on copper, graphite, aluminium and mild steel heat transfer surfaces at surface temperatures 54–56°C, from turbulent solutions (Re 22,000) of bulk temperature 30 °C, has been studied using thermal resistance and corrosion potential measurements and scanning electron microscopy. The rate of CaCO₃ scale nucleation and growth decreases in the order mild steel > aluminium > copper and graphite. Scale nucleation apparently proceeds from the very outset, throughout an apparent thermal induction period, the end of which appears to be associated with the development of nuclei into aragonite clusters. The differing scaling susceptibilities of the materials are directly related to their corrosion susceptibilities. Studies on aluminium highlight the importance of the nature and integrity of surface oxide films in determining scaling susceptibility. Under the conditions examined, scales consist primarily of aragonite, with small amounts of calcite and vaterite. Mild steel surfaces apparently favour growth of “flower” vaterite.     

炼化厂水冷器常见腐蚀形式与控制措施

近几年对炼化厂生产装置进行腐蚀调查发现,各厂水冷器结垢及腐蚀问题是装置主要腐蚀问题之一,水冷器腐蚀结垢问题严重影响装置正常运行。各炼化厂水冷器采用涂料防腐、阴极保护、材质升级、水质控制等措施减缓腐蚀。同时,在装置运行期间保证水冷器管束内部流速,控制循环水出口温度,可有效减轻水冷器结垢和垢下腐蚀。在装置大检修期间,开展水冷器专项腐蚀调查,排查水冷器存在的泄露隐患,总结分析水冷器运行存在的问题,以便采取有针对性的控制措施。通过这一系列措施,可以有效改善水冷器腐蚀问题和结垢问题。     

一种HAP型高效缓蚀阻垢剂的研制及应用

目的通过对延长油田JX区块腐蚀结垢情况分析,针对性地研制并筛选缓蚀阻垢剂配方,获得阻垢、缓蚀效果最佳的HAP缓蚀阻垢剂。方法采用EDTA滴定法、称重法和腐蚀挂片分析技术,在温度为90℃时,对缓蚀阻垢剂的缓蚀效果和阻垢性能进行评价,通过反复对比分析,筛选配方,并进行了现场试验。结果与未添加缓蚀阻垢剂时相比,油井产出液分离水的腐蚀速率由0.125~0.161 mm/a下降到0.023~0.034 mm/a,缓蚀率达到了80%以上;混合结垢量由130~290 mg/L下降到7~15 mg/L,阻垢率达到了91%以上。结论应用EDTA滴定法、称重法和腐蚀挂片分析技术优选了缓蚀阻垢剂配方,在高温环境下,缓蚀阻垢剂综合性能优良,现场试验中的缓蚀阻垢效果显著。     

Characterisation and understanding of the corrosion behaviour of the nugget in a 2050 aluminium alloy Friction Stir Welding joint

The corrosion behaviour of the nugget of a Friction Stir Welding joint employing a 2050 Al–Cu–Li alloy was investigated. The results showed that the nugget was susceptible to both intergranular and intragranular corrosion. Such corrosion behaviour was related to microstructural heterogeneities observed on a microscopic scale. Furthermore, heterogeneities in the corrosion behaviour of the nugget observed on a macroscopic scale were evidenced by a different corrosion behaviour from the top to the bottom of the nugget and by a localisation of the corrosion damage related to the “Onion ring structure”. Critical microstructural parameters were identified to explain the results.     

西部油田油管腐蚀结垢机理研究

通过对西部某油田油管腐蚀结垢现状调查、单井采出液成分分析和垢样XRD分析，结合油管结垢趋势预测及室内高温高压腐蚀试验，探讨了油管腐蚀结垢机理。结果表明：垢物主要是CaCO3、CaSO4和铁锈产物，在结垢出现的同时伴随油管腐蚀的发生。影响油管腐蚀结垢的主要因素是采出液中含有丰富的的Ca^2＋、HCO3^-,Cl^-以及原油伴生气中的CO2含量较多。该油田存在严重的腐蚀结垢趋势。     

Development of Corrosion Assessment Diagrams for High Temperature Chlorine Corrosion. Part I: State of the Art and Development of the Basis for a New Extended Approach

As in many other areas of material science there is an increasing need for computational tools predicting materials behaviour, also in high temperature corrosion. In many cases stability diagrams have been developed for the assessment of high temperature corrosion resistance of metallic materials where the potentially formed corrosion products are plotted as fields of stability as a function of the activities or partial pressures of the species in the reaction environment. One major drawback of these diagrams is that they only contain solid or liquid phases as reaction products, but in halogen induced high temperature corrosion volatile metal halides are also formed. In order to overcome this drawback, the present paper deals with the development of a new type of diagram for high temperature halogen corrosion which will be developed and discussed for the example of oxygen/chlorine environments and which will be named “dynamic” quasi-stability diagram. In part I of the paper, the basis for this new approach to the corrosion resistance assessment of metals under chlorine environments is established using the present understanding described in the literature. A comparison is made between the concept of the conventional stability diagram and the recently developed “static” quasi-stability diagram, where in the latter case the evaporation of the gaseous metal chloride phases is taken into account through the use of a critical metal chloride partial pressure of 10^?4 bar, as a criterion distinguishing critical and non-critical corrosion conditions. Concluding from the existing knowledge, the fundamentals for the new improved approach are developed in the form of a “dynamic” quasi-stability diagram. This new type of diagram is based not only on thermodynamic considerations (as for the diagrams existing so far) but also on the products and reactants flow through a gas boundary layer formed on the material surface. As a consequence, in this approach the criterion for corrosion resistance is given in terms of a metal recession rate for dynamic conditions as encountered in most industrial applications. In part II diagrams of the new type will be established for the most common alloying elements, i.e. Fe, Ni, Mo, Cr, Si and Al, and a comparison with experimental data will be performed.     

宝浪油田供热系统腐蚀和结垢的原因及其控制

对宝浪油田供热系统腐蚀物和垢样进行了分析，锅炉回水管线腐蚀主要为氧腐蚀，锅炉结垢系HCO3^-受热分解生成CO3^-，与其它离子结合形成。采取热力除氧和亚硫酸钠除氧，加强停用保护，投加阻垢剂等措施后，收到了缓蚀和阻垢的良好效果。     

常规水稳剂对HSn70-1A铜合金的腐蚀性能研究

通过旋转挂片失重法来测定几种水质稳定剂HPAA、HPMA、PBTC、HEDP、DTPMP、有机膦磺酸、马来酸-丙烯酸共聚物对HSn70-1A铜合金的腐蚀情况。研究表明，阻垢剂对铜离子有较强的络合作用，使用不当会造成腐蚀；常规使用浓度下，阻垢剂对铜合金HSn70-1A的腐蚀一般都是脱锌腐蚀；造成铜合金腐蚀和溶解的水质稳定剂浓度应视具体环境来确定。     

Influence of chloride and moisture content on steel rebar corrosion in concrete

Reinforced mortar samples were exposed in humidity chambers with different relative humidity or exposed in cyclic moisture conditions. The rebars were in an “as received” condition meaning that the preexisting oxide scale were intact. The lowest chloride concentration that initiated corrosion was 1% Cl^? by mass of cement, corrosion was then observed for samples exposed at 97% relative humidity. It is suggested that the corrosion rate decreases when samples are exposed to a relative humidity lower than 97%. The results indicate that threshold levels should be evaluated at rather humid conditions (97%) despite the fact that the maximum corrosion rate at higher chloride levels is observed in the interval 91–94%. For samples exposed to cyclic moisture conditions, a lower chloride concentration was needed to initiate corrosion compared to samples exposed in static moisture conditions.     

Fracture roughness scaling and its correlation with grain boundary network structure

Roughness scaling laws for intergranular cracks deviate from self-affine (fractal-like) behavior at length scales related to the polycrystalline microstructure. We consider two versions of the same alloy material with many of the same microstructural length scales but differing in their processing history: one conventional and one grain boundary engineered. The engineered material, processed to contain a high fraction of “special” grain boundaries, fails more slowly and more isotropically. We present evidence that the difference is determined by processes related to clusters of twin-related grains, shown through analysis of scales of the fracture roughness measured with confocal microscopy and the special grain boundary network determined by electron backscatter diffraction. Above the cluster scale, the fracture roughness exponents in the two materials are nearly indistinguishable (confirming theoretical predictions); below this scale conventional cracks exhibit correlations indicating consistently weak paths for crack propagation, suggesting percolation of “random” boundaries.     

Einige Anmerkungen zur Arbeit von H. Leyerzapf „Zur Bedeutung und Geschichte des Wortes ‚Korrosion’︁”︁ (Werkstoffe und Korrosion 36 (1985) 88–96) [1]

Some comments to H. Leyerzapf's paper ”?A contribution to the meaning and history of the term “corrosion” A critical comment on H. Leyerzapf's paper (Werkst. Korros. 36 (1985) 88–96) is given. His restriction on the term “corrosion” is regarded as unjustified, since in the historical context, the word “rust” (and its equivalents in all languages) is of the same importance, and this word, too, was used as a technical term. This fact is illustrated by examples from the author's own research into the history of corrosion research. It cannot be said either that corrosion theories were missing in earlier corrosion research. By reference to the interdisciplinary character of this field of research is shown that periods of minor activities were only apparent rest periods because the evolution in these periods occurred in other disciplines.     

Effect of Caand Mg on corrosion and scaling of galvanized steel pipe in simulated geothermal water

In this paper, the effects of scaling ions (Ca²⁺ and Mg²⁺) on corrosion and scaling processes of galvanized steel pipe in geothermal water are presented. Spherical corrosion products and needle-shaped scale coexisted on the pipe surface. The concentration of Zn²⁺ and OH⁻ affected the nuclei formation of scale. The corrosion products and scale were identified as Zn(OH)₂, ZnO, CaCO₃ and MgCO₃, respectively. When scale formed on the galvanized steel pipe, the corrosion rate slowed down and the pitting region became smaller.     

Anticor type Romanian made corrosion inhibitors for refinery and petrochemical plant equipment

The anticorrosion treatment of refinery and petrochemical units in many cases are using corrosion inhibitors. SC ZECASIN‐Brazi is a research and manufacturing company specialised in following products: neutralizers, cathodic inhibitors, organic inhibitors, filmforming inhibitors, antifouling agents, biodispersant agents, inhibitors for chemical decrustation, passivators. The products are manufacturing under the name “ANTICOR”. The corrosion tests have been performed using gravimetric, volumetric, electrochemical and metallographic methods. Recommendations for the continuous use of the inhibitors have been made, based on the results of the laboratory, pilot and industrial scale tests. The effect of using inhibitors mentioned is in 80% decreasing of the corrosion process, and previous localized corrosion and blistering by diffussion of atomic hydrogen.     

Hochtemperaturkorrosion hochlegierter Stähle unter simulierten Müllverbrennungsbedingungen

High temperature corrosion of high alloy steels in simulated waste incineration environments The corrosion of high alloy steels was investigated in discontinuous exposures in N₂-O₂-HCl-SO₂ at 600°C with and without deposits, taken from a waste incinerator. Additions of 500–3000 vppm HCl to N₂-O₂ leads always to accelerated corrosion due to the formation of Cl₂. The Cl₂ diffuses through cracks and pores of the oxide scale and mainly FeCl₂ is formed at the metal/scale interface; by evaporation and outward diffusion through the oxide scale it is oxidized to Fe₂O₃ (“active oxidation”). After addition of SO₂ the corrosion process is retarded by sulfide formation on the metal-chloride. At 600°C the main corrosion process under deposits is “hot corrosion” caused by a sulfate melt. In N₂-O₂ oxide scales are dissolved by basic fluxing, the corrosion products are PbCrO₄ and zinc-rich spinel. In N₂-O₂-SO₂ the oxide scales are dissolved by acidic fluxing as sulfates; under these conditions Cr₂O₃-layers are sufficiently resistent. In N₂-O₂-HCl, (K, Na) Cl is formed in the deposits and therefore catastrophic corrosion occurs by Cl₂. After addition of SO₂ to N₂-O₂-HCl the corrosion rate is decelerated and acidic behaviour of the melts is induced.     

Grundlagen der Entwicklung korrosionsbeständiger Legierungen

Fundamental aspects of the development of corrosion proof alloys After considering the basic aspects determining the corrosion resistance of alloys, the possibilities of improving this resistance are discussed. Apart from changing the thermo-dynamic stability and the inhibition of anodic or cathodic processes, the article is mainly concerned with the possibilities of “cathodic alloying” which strengthens the influence of cathodic processes. Small quantities of Pd, Cu or Re have the effect of improving the resistance of steel with high Cr content in sulphuric acid and formic acid (provided that no halogen ions are present). Similarly favourable effects are obtained with Pd admixtures (up to 1 per cent.) to Ti or TiNb alloys. As the inhibition of corrosion is much stronger than might be expected from the alloy component, it must be assumed that the following conditions must be fulfilled for the reaction to be effective the base metal must, in principle, be sutiable for passivation; the passivation currents must be limited; there must be an adequate negative passivation potential (so that a shift into the positive range is possible); there must be no proneness to transpassivity and pit corrosion within the range of the passivation potential. As the enhanced corrosion resistance is only obtained after a certain exposure to the medium concerned, it must be assumed that the cathodically effective component must first be concentrated in the surface.     

Untersuchungen zum Korrosionsverhalten von AlLi-Legierungen

Corrosion behaviour of aluminium-lithium alloys The AlLiMgCu alloy 8090 was studied in its texturated fine grained version “A” and in its recrystallized coarse grain structured version “C” in different artificially aged conditions in reference to several other AlLi alloys, each in its heat treatment condition of practical interest, and to the convetional alloy 2024 T3. The subject of research was the general corrosion behaviour of semifinished AlLi products, particularly sheet material, under alternate and permanent immersion conditions in neutral 3.5% sodium chloride solution; the stress corrosion behaviour was studied under constant load in the long transverse direction according to ASTM G44 and G49. The underaged conditions, which are the relevant conditions for technical application of the 8090 “A” and “C” sheets, showed an approximately equivalent or even better corrosion behaviour in comparison to the lithium-free alloy 2024 T3 in the corrosion tests with unloaded specimens. The threshold above which the AlLi alloy 8090 in some heat treatment conditions is attacked by stress corrosion cracking within the 30 days lasting constant load test depends on alloy composition, testing direction, grain size, stretch-forming, artificial ageing condition, surface pretreatment and the specimens' dimensions.     

Klärung der Einzelmechanismen bei der Schädigung von Kupfer unter Kavitationsbeanspruchung in wäßrigen Medien

Study of the individual mechanisms giving rise to the destruction of copper under cavitation in aqueous media An experimental method developed by the authors enables the overall destruction mechanism during cacitation corrosion to be subdivided into the two main components “mechanical destruction” and “corrosion”. With the aid of impressed current it is then possible in a defined way largely to control the ratio of the two components of attack. Mechanical sollicitation due to the successive formation and collapse of bubbles in the liquid corresponds to the pattern found in corrosion fatigue; the authors have indeed found the phenomenological pattern of corrosion fatigue in some systems (grain boundary attack by electrochemical action, glide line attack by mechanical sollicitation).     

集输管线硫酸盐还原菌诱导生物矿化作用调查

利用扫描电镜 (SEM)、能谱、X射线衍射仪 (XRD) 和超景深三维立体显微镜等表面分析手段,调查研究油田污水集输管线材料的腐蚀和结垢行为。实验结果表明,暴露在没有添加杀菌剂的污水中30 d的试样表面形成了大量的垢状沉淀物,局部放大可以发现以胞外聚合物为主的生物膜覆盖在试样表面,此时生物膜的厚度高达169.6 μm,生物膜中含碳酸盐垢和细菌代谢产物硫铁化合物,且膜下基体材料局部腐蚀孔深度达到23.96 μm。在连续添加100 mg/L有机胍类杀菌剂1个月后,试样表面覆盖物中以无机矿物为主,且膜层厚度较未添加的薄,厚度为48.6 μm,膜下腐蚀较均匀,局部腐蚀轻微。硫酸盐还原菌参与的生物作用是管线局部腐蚀穿孔的主要原因之一。