侏罗系油井套管破损原因分析及采油工艺防腐措施优化

Analysis of Casing Damage in Jurassic Oil Wells and Anticorrosion Measures for Optimization Oil Production Technology

在侏罗系油井套管破损严重区块典型油井套管破损规律和破损原因调研分析的基础上,通过室内试验和现场腐蚀监测结果,探讨加深花管采油工艺防腐措施的可行性。结果表明:典型套管破损位置均在动液面以下,即主要集中在1000 m以下管段;套管破损以内腐蚀穿孔为主要特征,套管破损井段平均温度约为60℃;含水率及CO_(2)含量过高是导致套管发生腐蚀的主要原因;加深花管的采油工艺防腐措施使油套环空中油水界面位置下移,从而避开CO_(2)腐蚀的敏感温度区间,其在一定程度上可缓解侏罗系油井套管的腐蚀程度,但需与其他配套防护措施联合使用。最后,指出了采油工艺防腐措施的进一步优化方向。

Based on the investigation and analysis of the typicalcasing damage rules and causes of Jurassic oil wellwhich the casing damagewas serious,the feasibility of anticorrosion measures for optimizing oil production technology using deepened screen wasstudied through laboratory tests and on⁃site corrosion monitoring.The results show that thetypical casing damage locationsare all below the dynamic liquid level whichis mainly concentrated in the pipe section below 1000 m.The main casing damage feature is internal corrosion and perforation,and the average temperature of casing damage section is about 60℃.The high water content and CO_(2) content are the main reasons for casing corrosion.The measures for optimizing oil production technology using deepened screen can move down the position of oil⁃water interface within casing⁃tubing annulus,thus avoiding the sensitive temperature range of CO_(2) corrosion.The anticorrosion measures can alleviatecasing corrosion of Jurassic oil wells to a certain extent,but it needs to be used with other protection technologiestogether.The direction offurther optimization of anticorrosion measures for oil production technology is also pointed out.