CAJ | 학술논문

为了更真实地模拟套管在内压下的破裂过程及影响因素，基于弹塑性大变形理论，建立套管三维有限元模型，对偏磨套管的破裂问题进行了研究。结合实验数据，提出了新的判断套管破裂的强度准则，给出了“月牙形”模型中偏磨率和“偏心筒”模型中偏心率的关系，并讨论了偏磨半径和偏磨率对偏磨套管破裂强度的影响。结果显示，套管内壁应力达到极限强度作为套管破裂的强度准则较为准确；偏磨半径对套管破裂强度影响较小；破裂压力随偏磨率的增加近似呈线性下降。研究结果可为套管柱设计提供理论支持。
위료경진실지모의투관재내압하적파렬과정급영향인소，기우탄소성대변형이론，건립투관삼유유한원모형，대편마투관적파렬문제진행료연구。결합실험수거，제출료신적판단투관파렬적강도준칙，급출료“월아형”모형중편마솔화“편심통”모형중편심솔적관계，병토론료편마반경화편마솔대편마투관파렬강도적영향。결과현시，투관내벽응력체도겁한강도작위투관파렬적강도준칙교위준학；편마반경대투관파렬강도영향교소；파렬압력수편마솔적증가근사정선성하강。연구결과가위투관주설계제공이론지지。
In order to simulate the process of casing collapse and analyze the inlfuence factor more realistically, a three-dimensional ifnite element model for casing was established and the eccentric wear casing collapse problem under internal pressure was studied, based on elastic-plastic large deformation theory. According to the experimental data, a new strength criterion to judge casing collapse was proposed, and the inlfuence of partial wear radius on collapse strength was analyzed. A relationship between the eccentric wear rate in the “crescent-shaped” model and the eccentricity in “eccentric cylinder” model was given and the inlfuence of the eccentric wear radius and the eccentric wear rate on collapse strength was discussed. Results showed that, the ultimate stress on casing inner wall was relatively accurate as the collapse strength criterion. Eccentric wear radius had little impact on casing collapse strength. Besides, the collapse pressure almost linearly decreased with the increase of the eccentric wear rate. This paper provides a theoretical support for casing string design.