高温高压高含硫气井镍基合金油套管适用性评价方法  

A method for evaluating the applicability of nickel-based alloy tubing/casing in high-temperature,high-pressure,and high-sulfur gas wells

作　　者：孙金声[1] 王熙 曾德智[1] 杨建 李祚龙 罗建成 史胜垚 张林 SUN Jinsheng;WANG Xi;ZENG Dezhi;YANG Jian;LI Zuolong;LUO Jiancheng;SHI Shengyao;ZHANG Lin(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Engineering Technology Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610017,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室•西南石油大学 [2]中国石油西南油气田公司工程技术研究院

出　　处：《天然气工业》2024年第11期1-10,共10页Natural Gas Industry

基　　金：国家自然科学基金项目“静载、振动与腐蚀作用下H_(2)S/CO_(2)气井完井管柱螺纹密封面的力化学损伤机制研究”(编号:51774249)。

摘　　要：深层高温高压高含硫气藏腐蚀环境复杂且苛刻,井筒管柱合理选材是保障井筒完整性和安全的关键,目前仅以环境开裂和腐蚀速率为核心评价指标进行选材存在一定局限。为此,采用高温高压反应釜模拟了四川盆地东北部(以下简称川东北)地区某高含硫气藏气井服役的井筒环境,以腐蚀速率、应力腐蚀损伤程度、抗外挤强度、抗内压强度、抗拉强度和成本为指标构建了镍基合金油套管适用性层次结构评价模型,评价了BG2532、G3和SM2550镍基合金管材在苛刻环境中的耐蚀性能、应力腐蚀损伤和强度衰减规律,并定量评价了上述3种镍基合金管材的适用性。研究结果表明:①模拟工况条件下BG2532、G3和SM2550的腐蚀速率都符合油田控制指标,且SM2550耐蚀性能最好,腐蚀速率为0.0083 mm/a;②应力腐蚀试验后,3种合金管材的屈服强度和抗拉强度、断后伸长率和断面收缩率、硬化指数和断裂韧性都衰减,其中SM2550衰减率最小,力学性能较稳定;③依据适用性定量评价结果,川东北地区高含硫气井完井管材油管推荐选用顺序为:SM2550>BG2532>G3,套管选用顺序为:G3>SM2550>BG2532。结论认为,构建的高温高压高含硫气井镍基合金油套管适用性评价新方法为苛刻服役环境的油套管选材提供了有力依据,将有助于保障高含硫、特高含硫天然气的安全绿色效益开发。Due to the complex and harsh corrosion environment of deep,high-temperature,high-pressure,and high-sulfur gas reservoirs,the rational selection of materials for pipe string is crucial to ensuring wellbore integrity and safety.The current materials selection solely based on environmental cracking and corrosion rate as core indicators is limited to some extent.In this paper,a high-temperature and high-pressure reactor was used to simulate the service environment of a high-sulfur gas well in a high-sulfur reservoir in the northeastern Sichuan Basin,and a hierarchical structure model was constructed with indicators such as corrosion rate,stress corrosion damage degree,collapse resistance,burst resistance,tensile strength,and cost,to evaluate the applicability of nickel-based alloy tubing/casing.With this model,the BG2532,G3,and SM2550 nickel-based alloy pipes were evaluated for their corrosion resistance,stress corrosion damage,and strength degradation under harsh conditions,and their applicabilities were quantified.The results show that,under simulated working conditions,the corrosion rates of BG2532,G3,and SM2550 all meet the oilfield control indices,with SM2550 exhibiting the best corrosion resistance and a corrosion rate of 0.0083 mm/a.After stress corrosion testing,the yield strength,tensile strength,elongation after fracture,section shrinkage,hardening index,and fracture toughness of BG2532,G3,and SM2550 declined,with SM2550 demonstrating the smallest decline and thus relatively stable mechanical properties.Based on the quantitative evaluation of applicability,the recommended order of materials to be selected for pipes in high-sulfur gas wells in the northeastern Sichuan Basin is as follows:SM2550>BG2532>G3 for tubing,and G3>SM2550>BG2532 for casing.It is concluded that the proposed new method for evaluating the applicability of nickel-based alloy tubing/casing in high-temperature,high-pressure,and high-sulfur gas wells is instrumental for selecting materials for tubing/casing to be used in harsh conditions,the

关 键 词：深层超深层 高含硫气藏 镍基合金油套管 评价指标 腐蚀速率 强度衰减 应力腐蚀 

分 类 号：TE931[石油与天然气工程—石油机械设备]