A3碳钢在模拟油田水中的腐蚀行为研究

用极化曲线法探讨了A3碳钢在模拟油田水中的腐蚀电化学行为。试验了在不同矿化度、pH值、溶解氧及含S2-的模拟油田水中A3碳钢的腐蚀行为,并用电化学方法研究了缓蚀剂的缓蚀效果。结果表明,随着矿化度的增加,温度的升高,腐蚀速率增大;pH值在7~8之间为碳钢的钝化区;在中性或碱性条件下,碳钢的腐蚀主要受溶解氧的影响,溶解氧含量越高,腐蚀越严重;S2-的存在消除了溶解氧的影响,改变了腐蚀产物膜的组成,从而影响缓蚀剂的选择。     

尕斯油田注水系统腐蚀原因和影响因素研究

针对尕斯油田注水系统的腐蚀特征,通过电化学测试、腐蚀挂片等方法研究了各因素对N80碳钢腐蚀的影响。研究结果表明,尕斯油田的污水对N80碳钢的腐蚀主要是析氢腐蚀;S2-浓度增加,污水腐蚀性增强;pH＜6时,析氢腐蚀加剧;矿化度增加,以及温度升高都能使腐蚀速率增加。     

某海管在含H_2S/CO_2环境中腐蚀规律研究

通过模拟某油田腐蚀环境,研究了不同浓度的硫化氢对海管管线X65的腐蚀行为的影响,研究结果表明:微量硫化氢的加入减缓了腐蚀的发生,随着硫化氢浓度的增加,X65材料的均匀腐蚀速率呈现增大—减小—增大—减小的变化趋势,在25 ppm和300 ppm时出现极小值。在总压为2.5 MPa,CO_2分压为0.075 MPa环境条件下,当H_2S浓度≤50 ppm时,CO_2腐蚀占主导作用;当H_2S浓度≥100 ppm时,H2S腐蚀占主导作用。     

海上油田腐蚀探析及防护

通过分析南海某油田现场主要技术指标,确定导致腐蚀的主要影响因素包括高矿化度的水质、高含量的CO2以及H2S和硫酸盐还原菌(SRB);其中SRB是此油田腐蚀产生的最重要影响因素,也是产生点蚀的关键因素。通过在油井井下加入季铵盐衍生物类型的缓蚀剂,并定期应用季铵盐复合杀菌剂对整个系统进行杀菌处理,使油田的腐蚀得到了很好的控制。     

西江油田115油轮腐蚀探析

从115油轮现场工况入手,结合油田水质分析,分析了可能引起油田腐蚀的影响因素,结果表明:引起115油轮腐蚀的主要因素是硫酸盐还原菌(SRB)的滋生,同时伴有高矿化度引起的电化学腐蚀、CO2及H2S气体等引起的酸性腐蚀;就115油轮的腐蚀防护而言,一方面加注有效缓蚀剂,防止大面积发生腐蚀问题的发生,另一方面要定期杀菌,有效控制SRB的滋生与繁殖。     

元坝含硫气井油套环空腐蚀行为及机理分析

根据川东北元坝气田油套环空中存在腐蚀介质的现状,模拟开展了各种因素对钢片腐蚀行为的研究,并探讨了相关腐蚀机理。实验结果表明:Cl-会导致钢材表面保护膜致密性降低,钢片腐蚀速率随[Cl-]上升而增加;硫酸盐还原菌等细菌存在一个最佳活性温度,形成局部电池腐蚀钢片;当温度为160℃时溶解氧对钢片腐蚀速率达到0.734 mm/a;环空材质之间电偶腐蚀受电极面积比影响,但总体上腐蚀速率较低;CO2/H2S对钢片存在腐蚀敏感区域为60～80℃,钢片腐蚀速率随酸性气体压力增大而增加。     

套管寿命预测软件在盐池采油厂的应用

盐池采油厂的高矿化度地层水溶解氧、CO2和细菌(SRB),容易引起套管的腐蚀损坏,出现事故影响了油田的生产。基于此,运用De.Warrd模型编制套管腐蚀寿命预测软件,可以预测套管寿命,减少套损引起的事故,从而提高油田生产。     

L290钢在H2 S/CO2环境中的腐蚀行为研究

在H_2S与CO_2共存的腐蚀介质条件下油气田管线及设备腐蚀问题突出,为了探究在此环境中L290金属的腐蚀行为,以某油田的管输介质为例,采用失重法实验的方式,探究试验温度、pH值、H_2S分压、Cl~-浓度四种因素对于腐蚀规律的影响,并通过观察微观形貌与研究元素成分分析腐蚀产物特征:(1)L290钢材的腐蚀速率随着实验温度的升高呈增大的趋势,在70℃时最大腐蚀速率达到0.692 mm/a;(2)材料腐蚀速率随油田模拟水溶液中的pH值的减小而呈现出增大的趋势,在pH=5时测得腐蚀速率高达到0.802 mm/a为极严重腐蚀程度;(3)材料腐蚀速率随着硫化氢分压的升高而呈现出增大趋势,在P_(H2S)=50 kPa条件下材料腐蚀速率最大达到0.813 mm/a为极严重腐蚀程度。(4)在实验过程中Cl~-浓度增加的同时材料的腐蚀速率呈现出增高的趋势,并在Cl~-=70000 mg/L时,腐蚀速率最大达到0.711 mm/a为极严重腐蚀程度。相关实验数据对相关油田集输系统从思路与实施方面具有借鉴意义。     

油田采出水对注水系统腐蚀机理的探讨

目前,我国油田已经进入注水开采中后期,采出水占采出液60%～70%,甚有高达90%以上。采出水中富含H2S、HCO3^-、溶解氧、硫酸盐还原菌（SRB）、Cl^-、CO2这些都是导致腐蚀的主要原因。通过对集输站注水管线腐蚀产物进行电镜扫描（SEM）、能谱（EDS）分析、X衍射及腐蚀产物成分定量分析（容量法）;通过室内静态腐蚀挂片实验,研究具有腐蚀物质不同浓度对腐蚀性的影响,进一步探讨腐蚀机理。     

靖边采油厂青阳岔区块油井缓蚀剂筛选与评价

靖边采油厂青阳岔区块部分油井产出液呈弱酸性,矿化度、H2S、CO2、CO32-、HCO3-及溶解氧含量高,腐蚀性强,腐蚀速率为0.199-0.386m/a.内室研究表明,加入80mg/L YC05缓蚀剂后,产出液腐蚀速率降为0.054mm/a.通过现场3个月的跟踪分析,添加缓蚀剂的油井产出液平均腐蚀均小于0.076mm...     

Study of the variational patterns for corrosion kinetics of carbon steel as a function of dissolved oxygen and NaCl concentration

The simultaneous occurrences of electrochemical reactions responsible for corrosion of carbon steel in NaCl solutions have been analyzed on the basis of the mixed potential theory in order to determine the combined effect of dissolved oxygen and NaCl concentration on corrosion potential, corrosion current density and hydrogen evolution. This was achieved through the estimation of the functional dependence from both, the dissolved oxygen and the NaCl concentration for each of the kinetic parameters involved in the corrosion process. The main finding is the existence of the critical dissolved oxygen value at which a notorious change in variational pattern for corrosion potential, corrosion current density and hydrogen evolution is observed. The validity of this feature is supported from experimental evidence reported in previous investigations. In this context the role of pitting corrosion, oxide film and diffusional effects are discussed.     

Effects of sulfate-reducing bacteria on the corrosion behavior of carbon steel

The influences of the growing process of sulfate-reducing bacteria (SRB) in seawater system on the medium state and corrosion behavior of carbon steel were studied by detecting solution state parameters and using corrosion electrochemical methods. The growing process of SRB in the seawater shows the three stages of growing, death and residual phases. The solution state parameters of the concentration of sulfide, the pH value and the redox potential changed during the three stages of the SRB growing process. And the corrosion rate of D36 carbon steel was accelerated during the growing phase and stable during the death and residual phases. The results indicate that the medium state and the corrosion rate of the steel do not depend on the number of active SRB, but depend on the accumulation of the metabolism products of SRB.     

Influence of sulphate-reducing bacteria on environmental parameters and marine corrosion behavior of Q235 steel in aerobic conditions

The growth cycle of sulphate-reducing bacteria (SRB), Desulfovibrio caledoniensis, and the effect of SRB on the environmental parameters and corrosion behavior of Q235 steel during a growth cycle in aerobic (air- and O₂-saturated culture solutions) and anaerobic (N₂⁻ saturated culture solutions) conditions were investigated. Oxygen dissolved in the culture solutions induced slow growth and fast decay of SRB. The growth process of SRB under anaerobic and aerobic conditions influenced sulphide anion concentration (Cs2−), pH, and conductivity (κ). The values of Cs2− and κ under aerobic conditions were lower than those under anaerobic conditions, and the pH values increased from O₂- to air- to N₂-saturated culture solutions. Aerobic conditions induced the open circuit potential (E_OC) to shift in the positive direction after the stationary phase of SRB growth. The charge transfer resistance (R_ct) increased quickly during the exponential growth phase, almost maintained stability during the stationary phase, and decreased after the stationary phase in all three conditions, and the impedance magnitude decreased from O₂- to air- to N₂-saturated culture solutions. The biofilms induced by SRB were observed by scanning electron microscopy (SEM) under aerobic and anaerobic conditions, and energy dispersive spectroscopy (EDS) was performed in abiotic and SRB-containing systems to distinguish the corrosion products. The reasons for the effects of SRB on the environmental parameters and corrosion behavior of carbon steel are discussed.     

脱氮硫杆菌生长特性及其对碳钢SRB腐蚀的防护作用研究

将脱氮硫杆菌(TDN)作用于被硫酸盐还原菌(SRB)微生物腐蚀的碳钢,研究了SRB和TDN生长特性及最适生长条件.利用静态挂片法研究SRB在不同环境下的腐蚀行为,以及TDN的防护效果;并借助扫描电子显微镜、X-射线能谱仪等研究了腐蚀后钢片的形貌及腐蚀产物.结果表明,SRB和TDN生存条件相似并可共存于同一环境;SRB可加速对X70钢的腐蚀,若有TDN共存时腐蚀程度明显降低,且TDN可消耗SRB代谢的具有腐蚀性的硫化物从而减轻SRB对钢基体的腐蚀.     

一株分离自输油管线中的硫酸盐还原菌生理生化特性及腐蚀行为研究

从塔里木某输油管线中分离出一株硫酸盐还原菌(SRB),并对其生理生化特性及腐蚀行为进行研究。结果表明:该株SRB在不同碳源培养基中生长速率存在明显差异,最适生长温度为35℃左右,最适p H在7.5左右,最适Na Cl浓度在0.5%左右;接菌溶液中Q235钢片的腐蚀速率达到0.043 6 mm/a,远大于其在无菌溶液中的腐蚀速率。     

用线性极化法研究碳钢在几种酸性介质中的腐蚀行为

采用线性极化法评价碳钢分浓硫酸、氢氟酸及其混酸中的腐蚀情况,讨论了不同酸性介质中温度、浓度对线性极化电阻Rp的影响规律.研究结果表明:混酸会加重碳钢的腐蚀;碳钢在70%H2SO4 20%HF中Rp最小;单组分的H2SO4、HF中,碳钢的Rp都随着温度的增加而减小;H2SO4的浓度对碳钢的腐蚀有较大的影响.     

High-temperature desulphurization of low-CV fuel gas

Experimental results on desulphurization of synthesized low-CV fuel gas using Western Kentucky No.9 gasifier coal ash as the sorbent are presented; oxides of iron in the ash react with the hydrogen sulphide, and ferrous and ferric sulphides are formed. Fixed beds of ash, held at 1000 K, removed 99% of the hydrogen sulphide at a concentration of 1.25% and a throughput of 2000 h⁻¹. Increasing temperature, pressure, sulphide concentration and space velocity increased the sorption capacity of the ash markedly. In the conditions tested, results were consistent with diffusion control from laminar flow. Spent ash was regenerated by passing air through the beds, when sulphur dioxide was evolved and ferric oxide reformed. Potentials for other chemical reactions were examined by chemical equilibrium; the gases hydrogen, carbon dioxide, carbon monoxide and water react during desulphurization and their concentrations reach equilibrium. It is suggested that gasifier coal ashes having significant iron content are suitable sorbents for high-temperature desulphurization from synthetic low-CV fuel gases derived from coal.     

Durability of concrete incorporating large volumes of low-quality fly ash

The carbonation, corrosion of steel reinforcement in concrete and corrosion resistance of concrete, incorporating large volumes of low-quality fly ash (LVLQFA), were studied. The effect of concentration of carbon dioxide used in the experiment on estimating the carbonation resistance of LVLQFA concrete were also investigated. Test results show that the LVLQFA concrete with an activator has good carbonation and corrosion resistances of steel reinforcement. The corrosion resistance of LVLQFA concrete is better than that of the control concrete. The concentration of carbon dioxide used in the experiment has considerable effect on estimating the carbonation resistance of LVLQFA concrete.     

钼酸盐复配体系对碳钢缓蚀作用研究

本文采用腐蚀失重、电化学阻抗谱、极化曲线和扫描电镜(SEM)等方法研究了钼酸钠及其与磷酸氢二钠的复配体系在3.5%NaCl介质中对碳钢的缓蚀性能。结果表明,与钼酸钠单独使用时相比,与磷酸氢二钠的复配使用能够提高其缓蚀效率。当钼酸钠与磷酸氢二钠两种缓蚀剂的复配比为3∶7时,对Q235的缓蚀效果最佳,缓蚀效率达到90%,能更有效地抑制碳钢的腐蚀。