高温高压高酸性油气井用尾管顶部封隔器关键技术研究  

Research on the Key Technologies of Liner Top Packer for HT/HP and High Acidic Oil and Gas Wells

作　　者：尹慧博[1] 张瑞[1] 陈武君 李夯[1] 马兰荣[1] YIN Huibo;ZHANG Rui;CHEN Wujun;LI Hang;MA Lanrong(Sinopec Research Institute of Petroleum Engineering,Beijing,100101,China)

机构地区：[1]中国石化石油工程技术研究院,北京100101

出　　处：《石油钻探技术》2018年第5期63-68,共6页Petroleum Drilling Techniques

基　　金：国家科技重大专项课题"高压低渗油气藏固井完井技术"(编号:2016ZX05021005);中国石化科技攻关项目"ф178×ф127(ф114)mm双防旋转尾管悬挂器的研制"(编号:P14113)联合资助

摘　　要：针对尾管顶部封隔器在高温高压高酸性油气井环境中易腐蚀失效导致环空带压等问题,开展了封隔器耐温、耐压、耐腐蚀关键技术研究。根据尾管顶部封隔器各部件的特点及高温高压高酸性油气井对其性能的需求,进行了合理的选材,采用浸泡试验、应力腐蚀试验和电化学测试等方法评价了主要金属材料的均匀腐蚀、点蚀、应力腐蚀开裂性能及电偶腐蚀风险;测试了所选橡胶材料的耐温、耐压和耐腐蚀性能。试验发现,镍基合金718具有良好的抗均匀腐蚀、点蚀和应力腐蚀开裂的性能,可作为封隔器的主要金属材料;13Cr不锈钢和低合金钢与镍基合金718偶接使用时电偶腐蚀速率较小,可以作为主要的辅助材料;改性的四丙氟橡胶材料在150℃、H_2S分压3.5MPa、CO_2分压3.0MPa环境下腐蚀96h后力学性能保持率均在90%以上,用其加工的封隔器胶筒在高酸性腐蚀环境下具有良好的气密封性能。采用上述材料制备的尾管顶部封隔器在元坝10-3井进行了现场试验,结果显示该封隔器性能可靠,表明选材合理。研究认为,改进后的尾管顶部封隔器是解决高温高压高酸性油气井环空带压等问题的有效手段。The key technologies for the HT/HP and high corrosion resistance of the top packer liner have been studied pertinent to the problems of corrosion failure and even Sustained Casing Pressure(SCP)under the environment of HT/HP and high acidic oil and gas wells.According to the characteristics of each component of top packer liner and the performance requirements of such wells,a reasonable material selection was carried out,and the uniform corrosion,pitting,stress corrosion cracking and galvanic corrosion risks of the main metal materials were evaluated by immersion test,stress corrosion test and electrochemical test.Later,tests for temperature resistance,pressure resistance and corrosion resistance of selected rubber materials were conducted.The study found that 718 nickel-based alloy has good resistances to uniform corrosion,pitting and stress corrosion cracking,can be used as the main metal material of the packer.Further,13Cr stainless steel and low alloy steel have a low galvanic corrosion rate while contacting with 718 nickel-based alloy,and they can be used as the main auxiliary material.The modified tetra propylene rubber material presents a mechanical performance retention rate of 90%or higher after placing into corrosive environments for 96h at temperature of 150℃,H 2S partial pressure of 3.5 MPa,CO 2 partial pressure of 3.0 MPa.The packer element processed with such rubber has good tight gas performance in highly corrosive acidic environments.The top packer liner manufactured with the above materials was tested in Well Yuanba 10-3.The test results show that such top packer liner is reliable,indicating the practical materials selection.This research s uggests that the modified top packer liner is an effective means for solving the problems of SCP and similar problems existing in HT/HP and high acidic oil and gas wells.

关 键 词：高温 高压 封隔器 二氧化碳腐蚀 硫化氢腐蚀 金属 橡胶 

分 类 号：TE925.2[石油与天然气工程—石油机械设备]