Evaluation and optimization of the integrity of HDD installed pipelines

水平定向钻井（HDD）用于在水体、道路和其他地面障碍物下安装管道和公用设施，而传统的露天施工是不可行的。HDD过程包括沿预定的井眼方向钻孔，扩大井眼，并通过将管道拉入井眼内来安装管道。正在安装的管道受到复杂的应力和应变组合，而这些应力和应变组合尚不清楚。安装过程中产生的应力/应变会影响管道的使用寿命。对HDD安装进行更详细的调查需要评估轴向和周向应力，以及管段上施加的应变，因为它被迫符合井眼几何形状。这项研究将包括基于实际HDD安装过程中应变计测量的管道所经历的应力/应变分析，以评估管道的结构安全性。本研究计划将使用应变测量工具记录在不同条件和不同管道尺寸下管道安装的纵向和周向应变。这些数据将被分析以计算轴向、弯曲、环向、热应力和剪切应力。这些发现将与当前行业标准推荐的理论计算进行比较。该分析将为研究最新和先进的HDD安装管道设计规范的应用提供基础，并确定可能改进当前设计指南的任何领域。应力/应变分析还将包括起升管段并与井眼对齐时的起升作业。将进行单独的应变监测系统，以测量管道垂直、水平弯曲处的实际管道应变，有时两者同时弯曲。有限元（FE）模型也将被开发出来与实际测量结果进行比较。这些模型将根据现场测量结果进行验证，并对建模输入参数进行校准。这些校准参数将成为未来模型和设计的基础。

Horizontal Directional Drilling (HDD) is used to install pipelines and utilities beneath waterbodies, roads, and other surface obstacles where traditional open-cut construction is not feasible. The HDD process includes drilling a borehole along a pre-determined alignment, enlarging the borehole, and installing the pipeline by pulling it inside the borehole. The pipe being installed is subjected to a complex combination of stresses and strains that are not well understood. The stresses/strains that develop during installation have an impact on lifetime of the pipe operation. A more detailed investigation of the HDD installation requires evaluating axial and circumferential stresses, as well as the imposed strain on the pipe section as it is forced to conform to the borehole geometry. This research will include the analysis of stress/strain experienced by the pipe based on strain gauge measurements during actual HDD installations to evaluate the structural safety of pipelines.This research program will use a strain-measurement tool to record longitudinal and circumferential strains throughout the pipe installation under various conditions and different pipe sizes. This data will be analyzed to calculate axial, bending, hoop, thermal, and shear stress. These findings will be compared with theoretical calculations recommended by current industry standards. This analysis will provide a basis to investigate the application of more recent and advanced design codes for HDD installed pipelines, and identify any areas that may improve the current design guidelines. The stress/strain analysis will also include pipe lifting operations while the pipe section is being lifted and aligned with the borehole. A separate strain monitoring system will be conducted to measure the actual pipe strain where the pipe bends vertically, horizontally, and sometimes a combination of the two. Finite Element (FE) models will also be developed to be compared against the actual measurements. These models will be verified against field measurements, and the modeling input parameters will be calibrated. These calibrated parameters will be the basis for future models and designs.