深海大尺寸取样钻柱力学行为数值研究
发布时间：2019-04-24 07:56
【摘要】：针对深海天然气水合物钻探取样钻具结构及工艺流程的特殊性以及所受载荷的复杂性,“天然气水合物钻探取芯工程样机及配套技术”课题组开发了无扰动保压保真取样钻具系统进行水合物的钻探取样。本文结合国内外研究现状,通过理论分析、数值计算的方法对取样钻柱的力学行为进行分析研究。首先,论文对取样钻柱的静态特性进行了计算分析。忽略取样过程中的动态因素,将取样钻柱所受外部载荷按照作用机理以静力等效方式施加到结构上,对取样钻柱的受力及变形特性进行了计算分析。得出最危险工况下,取样钻柱等效应力最大值为266MPa,发生在钻杆与钻铤连接部位的钻杆处。论文探讨分析了不同钻压、扭矩、波浪以及水流对取样钻柱静力学特性的影响规律,得到了钻压以及扭矩对取样钻柱等效应力影响较大、波浪以及水流对取样钻柱变形影响较大等结论,对钻具设计具有一定的指导意义。其次,论文对取样钻柱的振动模态进行了计算分析,得出了钻柱横向、纵向以及扭转振动的前20阶振动频率及相应的振型;研究了不同钻铤长度对取样钻柱振动频率的影响,计算得出不同钻铤长度下取样钻柱的前20阶振动频率值;为防止取样钻柱在钻探取样过程中发生共振,计算得到了取样钻柱发生共振时的临界转速。而后,在考虑惯性力及阻尼作用力的基础上,论文对取样钻柱的瞬态动力学特性进行了计算分析,探讨了在波浪、水流作用下以及波浪、水流与钻压、扭矩的联合作用下,取样钻柱危险位置处节点横向位移、纵向位移以及单元等效应力随时间的变化规律;得出了钻探取样开始阶段,取样钻柱横向以及纵向存在较大的振动等结论。最后,论文对取样钻柱的稳定性进行了特征值屈曲分析以及非线性屈曲分析,结果表明:非线性屈曲分析更加适合于取样钻柱的稳定性分析;计算分析得到了取样钻柱前10阶屈曲临界载荷,取样钻柱最大施加钻压不得超过60KN,对取样工艺制定具有重要指导意义。
[Abstract]:In view of the particularity of the structure and technological process of sampling drill tool for deep-sea gas hydrate drilling, and the complexity of load, The "Gas Hydrate drilling coring Engineering prototype and its supporting Technology" has developed the undisturbed pressure-preserving fidelity sampling tool system for gas hydrate drilling and sampling. In this paper, the mechanical behavior of sampled drill string is studied by means of theoretical analysis and numerical calculation according to the present research situation at home and abroad. Firstly, the static characteristics of sampled drill string are calculated and analyzed. Ignoring the dynamic factors in the sampling process, the external load on the sampled drill string is applied to the structure in a static equivalent manner according to the action mechanism, and the force and deformation characteristics of the sampled drill string are calculated and analyzed. Under the most dangerous condition, the maximum equivalent stress of the sampled drill string is 266MPa, which occurs at the connecting part of the drill pipe and the drill collar. In this paper, the influence of different drilling pressure, torque, wave and current on the statics characteristics of sampled drill string is discussed and analyzed. The results show that the effect of drilling pressure and torque on the equivalent stress of sampled drill string is greater. The conclusion that wave and current have great influence on the deformation of sampled drill string has certain guiding significance for drilling tool design. Secondly, the vibration modes of the sampled drill string are calculated and analyzed, and the first 20 order vibration frequencies and corresponding vibration modes of the horizontal, longitudinal and torsional vibrations of the drill string are obtained. The influence of different drill collar length on the vibration frequency of sampled drill string is studied, and the first 20 order vibration frequency values of sampled drill string under different drill collar length are calculated. In order to prevent the resonance of the sampled drill string during drilling, the critical rotation speed of the sampled drill string is calculated. Then, on the basis of considering inertia force and damping force, the transient dynamic characteristics of sampled drill string are calculated and analyzed, and the combined action of wave, current, drilling pressure and torque is discussed. The variation of transverse displacement, longitudinal displacement and element equivalent stress with time at the dangerous position of drill string is investigated. It is concluded that there is a large vibration in the horizontal and longitudinal direction of the sampled drill string in the initial stage of drilling sampling. Finally, the stability of sampled drill string is analyzed by eigenvalue buckling analysis and nonlinear buckling analysis. The results show that the nonlinear buckling analysis is more suitable for the stability analysis of sampled drill string. The critical load of the first 10 order buckling of the sampled drill string is obtained, and the maximum applied drilling pressure of the sampled drill string is not more than 60KN, which is of great significance to the formulation of the sampling process.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P634
[Abstract]:In view of the particularity of the structure and technological process of sampling drill tool for deep-sea gas hydrate drilling, and the complexity of load, The "Gas Hydrate drilling coring Engineering prototype and its supporting Technology" has developed the undisturbed pressure-preserving fidelity sampling tool system for gas hydrate drilling and sampling. In this paper, the mechanical behavior of sampled drill string is studied by means of theoretical analysis and numerical calculation according to the present research situation at home and abroad. Firstly, the static characteristics of sampled drill string are calculated and analyzed. Ignoring the dynamic factors in the sampling process, the external load on the sampled drill string is applied to the structure in a static equivalent manner according to the action mechanism, and the force and deformation characteristics of the sampled drill string are calculated and analyzed. Under the most dangerous condition, the maximum equivalent stress of the sampled drill string is 266MPa, which occurs at the connecting part of the drill pipe and the drill collar. In this paper, the influence of different drilling pressure, torque, wave and current on the statics characteristics of sampled drill string is discussed and analyzed. The results show that the effect of drilling pressure and torque on the equivalent stress of sampled drill string is greater. The conclusion that wave and current have great influence on the deformation of sampled drill string has certain guiding significance for drilling tool design. Secondly, the vibration modes of the sampled drill string are calculated and analyzed, and the first 20 order vibration frequencies and corresponding vibration modes of the horizontal, longitudinal and torsional vibrations of the drill string are obtained. The influence of different drill collar length on the vibration frequency of sampled drill string is studied, and the first 20 order vibration frequency values of sampled drill string under different drill collar length are calculated. In order to prevent the resonance of the sampled drill string during drilling, the critical rotation speed of the sampled drill string is calculated. Then, on the basis of considering inertia force and damping force, the transient dynamic characteristics of sampled drill string are calculated and analyzed, and the combined action of wave, current, drilling pressure and torque is discussed. The variation of transverse displacement, longitudinal displacement and element equivalent stress with time at the dangerous position of drill string is investigated. It is concluded that there is a large vibration in the horizontal and longitudinal direction of the sampled drill string in the initial stage of drilling sampling. Finally, the stability of sampled drill string is analyzed by eigenvalue buckling analysis and nonlinear buckling analysis. The results show that the nonlinear buckling analysis is more suitable for the stability analysis of sampled drill string. The critical load of the first 10 order buckling of the sampled drill string is obtained, and the maximum applied drilling pressure of the sampled drill string is not more than 60KN, which is of great significance to the formulation of the sampling process.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P634
【参考文献】
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