油气井下CO_2动态腐蚀模拟试验装置的研制  

Development of Simulation Test Rig for Dynamical Evaluation of Corrosion Induced by Downhole Carbon Dioxide

作　　者：高斐[1] 楼一珊[1] 李忠慧[1] 浦尚树 韩福伟 郑旋[1] 常公喜[4] 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [2]中石化河南石油工程有限公司,河南南阳473132 [3]渤海钻探第三钻井公司,天津300280 [4]中原油田分公司采油五厂,河南濮阳457001

出　　处：《材料保护》2014年第7期48-51,66,共5页Materials Protection

基　　金：国家自然科学基金(51274047)资助

摘　　要：CO2腐蚀在石油行业中普遍而严重,室内模拟试验难度大,现有的动态腐蚀试验装置无法真实模拟井下流体的流动状态。研制了一种模拟性和实用性都较强的井下CO2动态腐蚀模拟试验装置。该试验装置不仅能够真实模拟井下油套环空及抽油泵吸入口附近腐蚀介质的流速和流态,还能评价井下动液面以上、动液面附近、动液面以下、泵吸入口附近、筛管以下等不同位置油套受温度、CO2分压、流速等因素控制下的腐蚀状态。结果表明:在现场工况条件下,试样腐蚀速率随温度、CO2分压、流速的增大而增大,与Corrtest Co.35 MPa耐腐蚀高压釜试验结果一致,并且较后者更接近于现场挂片试验结果;横向比较井下不同位置的腐蚀状况发现,泵吸入口附近套管的腐蚀速率最大,并且以局部腐蚀为主,腐蚀形貌与现场套管腐蚀穿孔特征相吻合。该装置结构合理,性能稳定,为研究井下CO2腐蚀机理及影响因素提供了新的测试手段和研究方法,具有很好的应用前景。A simulation test rig to dynamically simulate downhole CO_2 corrosion was developed.The test rig could simulate not only the condition of downhole tubing casing,flow velocity and flow pattern of corrosive medium near the oil pump suction mouth,but also the different corrosion conditions controlled by temperature,CO_2 partial pressure and flow velocity at the position of above,near,and below the dynamic liquid level,or near the oil pump suction mouth.The comparative test results showed that the corrosion rate increased with increasing temperature,CO_2 partial pressure and flow velocity,which well conformed to the results obtained with Corrtest Co.35 MPa anticorrosion autoclave.The corrosion rate at the pump casing mouth was the highest,and the local corrosion was dominant.The morphology of the corroded surfaces was consistent with the corrosion characteristics found in downhole field casing.The present test rig could provide new experimental method to study the mechanism of downhole CO_2 corrosion,and it exhibited promising application prospect.

关 键 词：井下CO2腐蚀 模拟试验装置 工况条件 流动状态 

分 类 号：TG174.3[金属学及工艺—金属表面处理] TE980[金属学及工艺—金属学]