温度对API—X60管线钢HeS／CO2腐蚀行为的影响

利用高温高压反应釜模拟高含硫气田H2S／CO2共存环境,在流动溶液介质中进行腐蚀试验,辅以扫描电子显微镜和X射线衍射仪等研究手段,探讨了温度对API—X60管线钢H2S／CO2腐蚀行为的影响。结果表明,随着温度的升高,API-X60管线钢的腐蚀速率先升高后降低,腐蚀形态由局部腐蚀趋于全面腐蚀,高温区有点蚀倾向。低温时形成的腐蚀产物以马基诺矿型晶体和铁的单硫化物为主,随着温度的升高,腐蚀产物以层片状马基诺矿型晶体为主,并出现少量磁黄铁矿型晶体,高温区则以磁黄铁矿型晶体为主。低温区点蚀的发生是由于腐蚀产物附着力差导致其覆盖率降低,膜层覆盖处的阴极效应促进了局部腐蚀。     

3Cr抗CO2和H2S腐蚀系列油套管开发

CO2、H2S腐蚀是石油天然气开采过程中的主要腐蚀问题。文章在分析油井管CO2腐蚀行为和腐蚀特点的基础上，介绍了抗CO2、H2S腐蚀油套管的研制过程并开发出腐蚀性能良好的3Cr系列经济型油套管。文章重点介绍了80、95、110等不同钢级成品管的力学性能，抗CO2、H2S应力腐蚀开裂性能。运用SEM扫描电境、X光电子能谱仪、X射线衍射、体视显微镜等分析了钢经腐蚀后的表面腐蚀产物的组成、结构，并对Cr元素改善钢的抗CO2腐蚀行为及机理进行了分析。     

CO2分压对油管钢CO2/H2S腐蚀的影响

采用高温高压釜、失重法和扫描电镜，对不同CO2分压(310．2642、930．7926、1551．3210、2171．8494kPa)条件下油管钢N80和P110的CO2／H2S腐蚀进行了研究。结果表明，随着CO2分压的升高，两种钢的CO2／H2S腐蚀速率均单调增加；除了CO2分压极低的情况以外，P110钢的腐蚀速率总是大于N80钢。     

低铬抗硫套管的H_2S/CO_2腐蚀行为研究

通过高温高压及H2S应力腐蚀开裂(SSC)实验,采用SEM、EDS、XRD和TEM技术,研究3Cr110S在模拟环境中的H2S/CO2腐蚀行为。结果表明:在模拟H2S/CO2高温高压腐蚀环境中,H2S腐蚀占主导作用,3Cr110S的均匀腐蚀速率为0.1272 mm/a,局部腐蚀轻微,试样表面腐蚀产物为FeS;在施加应力为72%、80%的最低屈服强度时,3Cr110S试样均未发生应力腐蚀开裂,具有良好的抗SSC性能;3Cr110S回火索氏体组织的条束之间位相差大,铬元素在晶界及晶内以粒状碳化物析出、位错纠结、弥散分布碳化物的位错定扎对SSC裂纹扩展起着良好的阻碍作用。     

多相流动状态下Cl~-对X70钢CO_2腐蚀的影响

用自制实验装置模拟起伏管路段塞流动条件下X70钢CO2腐蚀环境,通过电子显微镜、腐蚀挂片以及电化学在线监测等,对挂片表面形貌、腐蚀速率以及挂片在线腐蚀情况进行分析,采用实验与数值仿真研究了多相流动状态下Cl-对X70钢CO2腐蚀速率的影响,结果表明:在较低的Cl-浓度下,Cl-浓度对碳钢均匀腐蚀速率的影响存在一个临界浓度,超过临界浓度,碳钢均匀腐蚀速率大幅升高,继续增加Cl-浓度,对均匀腐蚀速率影响不大;在较高的Cl-浓度下,Cl-浓度对碳钢点蚀的影响也存在一个临界值,低于临界值,碳钢点蚀处在点蚀孔形成与钝化的动态平衡过程,高于临界值,这种平衡被打破。     

高含H2S和CO2环境中L80钢的腐蚀规律

 采用失重腐蚀方法研究了在模拟气田井下腐蚀环境中腐蚀影响因素(总压力、温度、腐蚀时间、H2S、Cl-、溶液流速),对套管钢(L80)腐蚀的影响规律,并用扫描电镜分析了腐蚀产物膜形貌。结果表明：60 ℃为L80钢在H2S+CO2腐蚀环境中的腐蚀临界温度,此时,L80钢的腐蚀速率最小;当总压力大于等于9 MPa,温度为120 ℃,H2S、CO2达到各自的超临界点,L80钢的腐蚀速率比温度为90 ℃时小;随腐蚀时间延长,腐蚀速率明显下降;相对在单一的CO2环境下,引入H2S可降低腐蚀速率;Cl-可促进L80钢的腐蚀;溶液流速加快,腐蚀速率提高。     

φ88.9×6.45mm90SS抗硫油管断裂原因分析

某油田使用的?88.9×6.45mm规格90SS油管在上井服务期间发生管体断裂事故。采用体视显微镜、金相显微镜、扫描电镜、X射线衍射和能谱分析等对油管断裂原因进行分析。结果表明,断裂失效油管化学成分、硬度、夹杂物含量均满足产品标准要求;抗硫油管在服役或储存过程中受到CO2环境的腐蚀,油管外壁形成大量局部腐蚀点蚀坑,降低了油管有效承载能力,使油管在H2S腐蚀环境下应力集中而受到较大的载荷,导致油管产生H2S应力腐蚀开裂,产生脆性断裂。     

油管钢高温高压CO2腐蚀行为研究

在高温高压条件下,对P110,N80,J55三种油管钢在模拟油田CO2环境下的腐蚀性能进行了研究评价,结果表明在静态条件下,三种钢对温度和压力的依赖关系均为类似抛物线规律,P110最不耐蚀。动态条件下对P110钢的进一步研究显示,由于流速的存在,与静态下相比,最高均匀腐蚀速率点向温度和CO2分压升高的方向移动。     

Ca~(2+)和Mg~(2+)对CO_2环境中点蚀形貌的影响

研究了 CO2 环境下 P110油管钢在不同介质中的点蚀形貌。结果表明 :点蚀形貌与腐蚀介质组成密切相关。在不含可生成难溶性碳酸盐的金属阳离子的介质中 ,P110油管钢的点蚀形貌为典型的 V形点蚀坑 ;在含 Ca2 +或 Mg2 +的介质中 ,点蚀则表现为 V形、半球形和闭口圆球形 3种形貌并存。蚀坑腐蚀产物的 SEM分析证实 ,Ca2 +、Mg2 +影响点蚀形貌的重要原因是 :这些离子的难溶性碳酸盐在点蚀坑上部优先沉积 ,有效地抑制了点蚀坑上部的金属溶解速度。试验中还发现 ,Cl-的存在并不是 CO2 环境中发生点蚀的必要条件 ,但 Cl-会加速点蚀的发展     

集输管道CO2/油/水环境中X65钢的腐蚀特征

通过高温高压动态反应釜实验模拟油田集输管道腐蚀环境,采用腐蚀失重、X射线衍射、扫描电镜和电化学分析等方法,研究了CO₂/油/水环境中X65钢的腐蚀行为. 结果表明:不同原油含水率条件下,X65钢CO₂腐蚀形态发生改变. 含水率较低(40%~50%)时,原油的浸润作用使X65钢表面发生均匀腐蚀,局部由于原油吸附不均匀出现点蚀特征;含水率在70%~80%之间时,原油对钢表面屏障作用减弱,生成的产物膜厚而疏松、局部脱落引发台地腐蚀;含水率为90%时,台地腐蚀破坏区域扩大,腐蚀加重. 原油可以明显改变腐蚀产物晶体颗粒大小、堆垛方式、产物膜结构以及化学成分. 在原油的缓蚀作用下,X65钢CO₂腐蚀过程的温度敏感点向低温段移动,出现在50℃左右,腐蚀速率降低区间变宽,X65钢耐蚀性增强.     

Corrosion behavior of super 13Cr stainless steel in a H_2S and CO_2 environment

The corrosion behavior of 95 ksi grade super 13 Cr stainless steel in an environment consisting of H_2S and CO_2 was investigated.The results reveal that for both loading methods(constant load and four-point bending),local corrosion occurred on the surface of the samples tested at ambient temperature but was absent from the samples tested at high temperatures.The local corrosion was caused by the formation of pits at nonmetal inclusions; the pits were formed under the action of stress in an acidic environment, which was due to an acid solution.Subsequently, the corrosion extended along the direction of stress.The sensitivity of stress corrosion cracking increased because of the local corrosion.     

BT80SS抗H2S腐蚀石油套管的研制

根据化学元素对H2S应力腐蚀的影响,选用C,Mn,Cr和Mo为合金元素,控制S和P等有害元素的含量,同时加入RE;根据钢管的组织对抗H2S应力腐蚀的影响,采用淬火后高温回火的热处理制度,生产出了具有自主知识产权的抗H2S套管,该产品具有良好的耐H2S腐蚀性能。     

螺旋焊管抗H2S应力腐蚀试验研究

通过对螺旋焊管抗H2S应力腐蚀的试验研究，提出了螺旋焊管抗H2S应力腐蚀的几种途径，并对我国在抗H2S应力腐蚀的研究方面提出了一些建议。     

温度对3Cr钢在CO2-O2环境中腐蚀的影响

摘要：为了研究注多元热流体吞吐热力采油过程中温度对油套管钢的影响,利用高温高压电化学釜模拟注多元热流体采油工况,分别在60、100和100～60℃循环的温度条件下,对3Cr钢进行失重腐蚀挂片试验和电化学腐蚀试验,利用高温高压电化学釜得到了3Cr钢在模拟工况下的腐蚀速率和极化曲线,并利用SEM、XRD、EDS分析了腐蚀产物膜形貌和成分。结果表明,温度由60升高至100℃时,腐蚀速率由0.552增长至1.920mm/a,在100-60℃高-低温循环时,腐蚀速率进一步升高至4.292mm/a;60和100℃时,腐蚀产物均为单层膜结构,且存在点蚀坑;在100-60℃高 低温循环时,腐蚀产物为双层膜结构,且存在直径约为4μm的腐蚀坑。温度主要影响3Cr钢腐蚀产物膜的结构和点蚀的形态,60和100℃时,点蚀坑内的聚集的Cl-离子使点蚀向纵深处发展,在100.60℃高 低温循环时,溶液中的O2促进了点蚀的横向发展,而腐蚀坑底部富集的Cr将阻碍点蚀的纵向发展。注多元热流体热力采油过程应充分考虑温度变化对3Cr钢腐蚀的影响,同时也要考虑温度变化引起3Cr钢点蚀的敏感性。     

Investigation of Mechanical Property of Oil Tube Steel P110S in High Temperature and High Pressure Environment Containing H2S/CO2

With the exploitation of high sour and deep oil well in china,the corrosion medium containing CO 2,H 2 S,Cl-and organic acid threaten the safety of oil equipment and tube steel severely.In this article,many experiments,including corrosion tests,tensile tests,hydrogen concentration measurement tests and SEM examinations,were performed to investigate the effect of H 2 S partial pressure and loading stress on the mechanical property of oil tube steel P110S in high temperature and high pressure environment containing H 2 S/CO 2.The tensile strength and yield strength during fracture process of P110S steel were obtained experimentally and the fracture morphology was analyzed by SEM.The results indicate that both tensile strength and yield strength decreased after corrosion.The damage of tensile strength and yield strength became serious with an increase in H 2 S partial pressure and loading stress.According to the fracture analysis,the fracture mode exhibited quasi-cleavage and dimple mixed fracture,and the area of quasi-cleavage pattern increased with H 2 S partial pressure and loading stress increasing.According to the results of tensile test and hydrogen concentration measurement test,the tensile property degradation is closely associated with diffusible hydrogen concentration of P110S steel in the H 2 S/CO 2 environment.     

Corrosion Behavior of 110S Tube Steel in Environments of High H2S and CO2 Content

 The corrosion behavior of the 110S tube steel in the environments of high H2S and CO2 content was investigated by using a high-temperature and high-pressure autoclave, and the corrosion products were characterized by scanning electron microscopy and X-ray diffraction technique. The results showed that all of the corrosion products under the test conditions mainly consisted of different types of iron sulfides such as pyrrhotite of Fe0. 95S, mackinawite of FeS0. 9, Fe0. 985S and FeS, and the absence of iron carbonate in the corrosion scales indicated that the corrosion process was controlled by H2S corrosion. The corrosion rate of the 110S steel decreased firstly and then increased with the rising of temperature. The minimum corrosion rate occurred at 110 ℃. When the H2S partial pressure PH2S below 9 MPa, the corrosion rate declined with the increase of PH2S. While over 9 MPa, a higher PH2S resulted in a faster corrosion process. With the increasing of the CO2 partial pressure, the corrosion rate had an increasing trend. The morphologies of the corrosion scales had a good accordance with the corrosion rates.     

TiB2含量对TiB2(p)/ZL205复合材料组织和耐蚀性的影响

以混合盐法制备不同TiB₂颗粒含量的TiB₂(p)/ZL205复合材料(其中TiB₂颗粒含量为2%,4%,6%,质量分数),通过热分析、扫描电镜(SEM)、电位极化测量和电化学阻抗谱测量等方法研究TiB₂含量对复合材料组织和耐蚀性的影响。结果表明:随着TiB₂颗粒含量的增多,复合材料凝固速度变慢,θ相析出量减少且析出温度由547.71℃降低到531.87℃。在铸态下,随着TiB₂颗粒含量增加,团聚物的数量和尺寸变大,晶间腐蚀和点蚀数量增加,自腐蚀电流密度(icorr)值提高,对电化学阻抗谱进行拟合,发现钝化膜电阻(Rf)以及电荷转移电阻(Rct)之和(Rf+Rct)逐渐减小,复合材料耐蚀性逐渐降低;经T6热处理后,复合材料中析出相的数量明显减少,且分布变得更加弥散,且随着TiB₂颗粒含量的增加,大尺寸颗粒团聚物内部变得更加弥散,复合材料耐蚀性逐渐降低。相比于相同颗粒含量铸态下的试样,T6热处理后晶间腐蚀和点蚀的数量相对减少,icorr值提高但幅度较小,(Rf+Rct)值明显提高,说明经T6热处理后复合材料耐蚀性有所提高。     

Effect of CO2 partial pressure on corrosion of 3Cr steel in high temperature steam environment

To study the effects of CO2 pressure on 3Cr steel in the high temperature steam environment. The corrosion tests were conducted in a HTHP autoclave to simulate the CO2 auxiliary steam drive. 3Cr steels were subjected to weight loss test under the condition of CO2 partial pressure range of 1-4MPa at 160??. The corrosion morphology and product composition were explored by SEM, EDS, XRD and XPS. The results show that the corrosion rate of 3Cr steel is lower than the corrosion control line of oil field (0. 076mm/a). With the increase of CO2 partial pressure, the corrosion rate firstly increases and then decreases. When the CO2 partial pressure is 1-2MPa, the FeCO3 generated by corrosion process gradually deposits on the surface of steel, and the number of FeCO3 crystals gradually increases. When the CO2 partial pressure is 3-4MPa, a small amount of FeCO3 crystals in the corrosion products dissolves, and the corners of FeCO3 crystals become rounder and the corrosion products become more compact. The results show that CO2 partial pressure mainly affects the deposition and dissolution of FeCO3 in the high temperature steam containing CO2 environment, which influences the protective properties of 3Cr steel corrosion products, thus further affecting the corrosion rate.