海上完井管柱作业过程力学性能分析

An analysis of the mechanical property of the offshore completion pipestring on operation

为了确定出完井管柱插入封隔器作业过程中管柱内部流体的最优排量,从力学角度对井下管柱进行理论分析,建立了管柱力学模型,从流体力学角度建立了排量与井斜角及管体特征参数之间的函数关系,推导了最优排量的求解方法。建立模型时假设伸缩短节可作为支撑点,管体视刚度的增加主要来自于流体的压力差。结果表明,完井管柱的弯曲程度受井斜角、弯曲段管柱长度、半径及流体排量的影响,管柱下入过程的最优排量与井斜角、管体弯曲特征及流体性能呈二次函数关系;现场实例计算及作业验证表明,建立的最优排量求解模型与实际情况吻合,能够为现场作业提供预测指导。

To determine the optimal discharge in the completion pipestring in the process of inserting the pipestring into the packer,the mechanical model of the pipestring was established through a theoretical analysis of the borehole pipestring from the mechanical perspective.The functional relationship was established between discharge,hole deviation angle and the characteristic parameter of the pipe body from the mechanical perspective and the solution of optimal discharge was derived.Suppose that the telescopic sub could be used as the supporting point when the model was established.The increase of the tubular rigidity came mainly from the pressure difference of the fluid.The result showed that the bending degree of the completion pipestring was subject to the effect of the hole angle,the length of the pipestring in the bending section and fluid discharge.There existed a quadratic function between the optimal discharge of pipestring,hole angle,tubular bending features and fluid property.The field example calculation and operating verification showed that the established optimal discharge solution model agreed with the practical condition.This study can offer a guide to field operation.