基于CT的含水合物沉积物电阻率测量系统设计与开发

Design and Development of a Resistivity Measurement System for Sediments Containing Natural Gas Hydrate Based on CT

摘要:

为满足从微观尺度研究沉积物孔隙中水合物分布对电阻率响应特性影响的需求，设计开发了基于CT的含水合物沉积物电阻率测量系统，包括天然气水合物实验模拟部分、电阻率测量部分和CT扫描部分，实现了水合物原位生成过程中电阻率和CT扫描图像的同时监测。通过开展甲烷水合物生成实验，验证了系统的可用性。实验结果表明：（1）电阻率随通过CT图像计算的水合物饱和度呈指数规律上升；（2）水合物饱和度为17.13%~30.72%时，阿尔奇公式中饱和度指数在1.57至2.48之间。所开发的测量系统为进一步开展不同环境条件下水合物生成分解实验提供了技术保障，为研究水合物微观分布对电阻率的影响以及优化水合物饱和度计算模型提供了数据支撑。

Abstract:

In order to meet the requirement of studying the influence of hydrate distribution in sediment pores on the resistivity response of sediments from microscopic scale, the resistivity measurement system for sediments containing hydrate based on Computed Tomography(CT) was designed and developed, included the gas hydrate experimental simulation part, the resistivity measurement part and the CT scan part, and the resistivity and CT images during hydrate formation in situ were simultaneous monitored, the method was established of CT image processing and hydrate saturation calculation model optimization. The availability of the system was verified by methane hydrate formation experiment, the experiment showed that (1) Resistivity increased exponentially with hydrate saturation calculated from CT images; (2) When the hydrate saturation ranged between 17.13% and 30.72%, the saturation index is between 1.57 and 2.48 in Archie's formula. The measuring device provided technical support for further hydrate formation and decomposition experiments of different environmental conditions. The measurement system was used as data support for studying the influence of hydrate microscopic distribution on resistivity in pores and optimizing the hydrate saturation calculation model.