渤海油田典型井套管损坏原因分析

发布时间：2018-09-11 10:50

【摘要】：目的查明渤海油气田油井套损原因,为后期预防与治理套损井奠定基础。方法对渤海油田32口套损井的套损情况进行检查和收集,从区块分布、套损纵向分布、生产年限、套损类型等方面进行统计。根据统计结果寻找相应规律,在套损点附近地层情况、冲蚀情况、空化腐蚀情况等方面,探究套损事故发生的原因和机理,并提出相应的预防措施,以提高井的使用年限。结果渤海油田套损井主要发生在一些老油田,套损点多集中在2000 m以内井段,位置主要分布在明化镇组底部水层及环空注入井的吸入口附近。腐蚀是渤海油田套管损坏的主要原因,注入流体、管外地层水是腐蚀的主要介质。长期高速流体冲刷、套管内流速突然变化、套管外无水泥环都会加剧套损的程度。结论为预防新井套损,建议固井时应彻底封固明化镇组底部存在水层的井段,避免套管与地层水直接接触,以减弱腐蚀作用。对于新的注入井,建议提高注入水水质标准,降低注入量,增大注入口过流面积,避免环空注入等方式,尽量减少注入流体与套管长期接触。
[Abstract]:Objective to find out the causes of casing damage in Bohai oil and gas field and to lay a foundation for preventing and controlling casing damage in later stage. Methods the casing damage of 32 casing damage wells in Bohai Oilfield was checked and collected, and the distribution of blocks, longitudinal distribution of casing damage, production years and types of casing damage were statistically analyzed. According to the statistical results, this paper explores the cause and mechanism of casing damage accident in the aspects of formation condition, erosion situation and cavitation corrosion situation near the casing damage point, and puts forward the corresponding preventive measures in order to improve the service life of the well. Results the casing damage wells in Bohai Oilfield mainly occurred in some old oilfields, and most of the casing damage points were located in the well section within 2000 m. The location was mainly located near the bottom water layer of Minghuazhen formation and the suction hole of the annulus injection well. Corrosion is the main cause of casing damage in Bohai Oilfield. Long-term high-speed fluid scouring, sudden change of flow velocity in casing, and no cement sheath outside casing will aggravate the damage degree of casing. Conclusion in order to prevent casing damage in new wells, it is suggested that the section where water layer exists at the bottom of Minghuazhen formation should be completely sealed during cementing so as to avoid direct contact between casing and formation water, so as to weaken corrosion effect. For the new injection wells, it is suggested to raise the water quality standard of injection water, reduce the injection volume, increase the flow area of the injection outlet, avoid the annulus injection, and minimize the long-term contact between the injected fluid and the casing.
【作者单位】：中海石油(中国)有限公司天津分公司;
【基金】：“十三五”国家科技重大专项(2016ZX05058)~~
【分类号】：TE931.2

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