氮气钻完井管柱的冲蚀机理分析及剩余强度预测

发布时间：2018-03-22 13:11

本文选题：氮气钻完井　切入点：管柱　出处：《西安石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文通过对管柱(钻柱、套管、油管)材料在不同条件下的冲蚀速率和磨损表面形貌的分析,研究了冲蚀角度、冲蚀速度等因素对氮气钻完井管柱冲蚀性能的影响,探讨了材料的冲蚀机理。在此基础上,采用Fluent软件对氮气钻井工况下环空气固两相流动规律进行了数值模拟研究。最后对管柱(钻柱、套管、油管)在不同条件下的剩余强度和剩余寿命进行预测。研究结果表明:随着冲蚀速度的提高,钻柱、套管、油管的平均失重率和平均壁厚减薄率均增加。钻井工况下,BG13Cr-110和S135两种钻柱材料的临界流速为20m/s,TP140套管材料在18°冲蚀角度的临界流速为20m/s,在75°冲蚀角度的临界流速为30m/s;生产工况下,P110油管材料无明显临界流速。延性材料30Cr Mo在较低冲蚀角下产生较大冲蚀,脆性材料Cr2O3在较高冲蚀角下将产生较大冲蚀。在相同冲蚀角下,喷涂Cr2O3的试样失重率均比30Cr Mo高。采用计算流体动力学方法建立了高速气体携岩冲蚀管柱的两相流模型。通过对环空气体流速、压力、岩屑浓度、钻柱和套管的冲蚀速率以及受到的剪切应力分布等的分析后发现,环空中心区域气体和岩屑的流速最大,由中心向套管内壁和钻杆外壁递减,直至壁面速度为零;钻杆母接头处岩屑沉积,浓度最大,并且钻杆母接头斜坡处剪切应力最大。在冲蚀试验的基础上,对在钻井工况条件下,钻柱BT13Cr-110和S135两种材料以及套管TP140材料的剩余强度和剩余寿命进行了计算;并且对在生产工况条件下,对油管P110材料的剩余强度和剩余寿命也进行了计算。
[Abstract]:Based on the analysis of erosion rate and wear surface morphology of pipe string (drill string, casing, tubing) under different conditions, the effects of erosion angle, erosion velocity and other factors on erosion performance of nitrogen drilling and completion string are studied in this paper. The erosion mechanism of materials is discussed. On the basis of this, numerical simulation of annular air-solid two-phase flow under nitrogen drilling condition is carried out by using Fluent software. Finally, the pipe string (drill string, casing, casing) is studied. The residual strength and residual life of tubing are predicted under different conditions. The results show that: with the increase of erosion speed, drill string, casing, Under drilling conditions, the critical velocity of BG13Cr-110 and S135 drilling string materials is 20 m / s at 18 掳erosion angle and 20 m / s at 75 掳erosion angle. 30 m / s; under production conditions, there is no obvious critical flow rate for the tubing material P110. The ductile material 30Cr Mo produces large erosion at lower erosion angles. The brittleness material Cr2O3 will produce larger erosion at higher erosion angle, and at the same erosion angle, The weight loss rate of the sample sprayed with Cr2O3 is higher than that of 30Cr Mo. A two-phase flow model of high speed gas carrying rock and erosion pipe string is established by using computational fluid dynamics method. After analyzing the erosion rate and shear stress distribution of drill string and casing, it is found that the velocity of gas and cuttings in the annulus center is the largest, from the center to the inner wall of casing and the outer wall of drill pipe, until the velocity of wall is zero; On the basis of erosion test, on the basis of erosion test, the maximum concentration of cuttings and the maximum shear stress at the slope of drill pipe mother joint are obtained. The residual strength and life of drill string BT13Cr-110 and S135 and casing TP140 are calculated, and the residual strength and life of tubing P110 are also calculated under production conditions.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE92

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