不规则充液管柱模型中几何参数与流体声速反演

Inversion of geometric parameters and ultrasonic wave velocity in an irregularly liquid-filled pipe model

充液管柱受管内外介质和环境的影响,会发生变形、腐蚀等问题,需要使用特定仪器进行定期检查以确保系统安全和可靠运行。实际测量环境复杂,管柱变形、仪器重力、居中器不当使用、管内流体性质变化等多重因素影响,使得测量仪器难以在理想的工作状态,从而降低检测精度。本文以套管井超声波测井为例来阐述以上问题,并结合超声波测量仪器的特点,设计了一套迭代优化算法。该算法能够在不规则充液管柱中,利用超声波测量到时定位仪器偏心测量轨迹、计算管柱内部流体声速、反演不规则管柱内边界。模拟和实测数据表明,本文提出的方法能够很好地预测仪器偏心轨迹,准确反演管柱内的流体声速并确定不规则管柱的几何参数(形状和位置)。该方法可以进一步提升套管井超声波测井仪器的使用性能,为后续进行管柱外的水泥评价提供可靠的约束。

Fluid-filled pipes are susceptible to deformation and corrosion due to the influence of the media inside and outside the pipe as well as environmental conditions.To ensure system safety and reliable operation,it is necessary to conduct regular inspections using specialized instruments.The practical measurement environment is complex,affected by factors such as pipe deformation,instrument gravity,improper use of centralizers,and variations in the properties of the internal fluid,all of which can hinder the measurement instruments from functioning ideally and reduce the precision of inspections.This paper focuses on ultrasonic logging within fluid-filled casings as a case study to address these challenges.Leveraging the characteristics of ultrasonic logging tools,we have developed an iterative optimization algorithm.This innovative algorithm allows for the ultrasonic measurements to accurately locate the eccentric trajectory of the inspection tool within an irregular fluid-filled pipe,calculate the ultrasonic wave velocity in the pipe′s internal fluid,and infer the internal boundaries of an irregular pipe.Both synthetic data and field data indicate that the proposed method can effectively evaluate the instrument′s measurement state,precisely determine the ultrasonic wave velocity in the internal fluid,and ascertain the geometric parameters(such as shape and position)of irregular pipes.This approach significantly improves the usability of ultrasonic logging tools in fluid-filled casings,providing reliable data for further assessments,such as external cement evaluation in the context of well casings.