基于分段涂层时域反射探头的天然气水合物测试平台开发及实验研究  

Development of a natural gas hydrate testing platform based on a segmented coating time-domain reflectometry probe and experimental study

作　　者：邢兰昌[1] 马子胜 刘宝[1] 魏伟[2] 韩维峰 XING Lanchang;MA Zisheng;LIU Bao;WEI Wei;HAN Weifeng(College of Control Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China;Department of Alternative Energy,PetroChina Research Institute of Petroleum Exploration&Development,Langfang 065007,China)

机构地区：[1]中国石油大学(华东)控制科学与工程学院,山东青岛266580 [2]中国石油勘探开发研究院新能源研究所,河北廊坊065007

出　　处：《实验技术与管理》2024年第10期141-149,共9页Experimental Technology and Management

基　　金：国家留学基金项目(202106455003);山东省自然科学基金项目(ZR2024ME090);山东省本科教学改革研究重点项目(Z2023256);中石油“十四五”前瞻性基础性重大科技项目(2021DJ4901)。

摘　　要：该文基于分段涂层时域反射(time-domain reflectometry,TDR)探头,开发了一套用于开展海洋沉积物中水合物模拟实验和TDR响应测试的平台。平台的硬件部分包括样品容器、TDR测试单元、温度测量单元;软件部分包括TDR测试单元和温度测量单元软件。通过标定TDR探头参数、校正分段涂层影响,平台可同步测量高电导率海洋沉积物表观介电常数和电导率。用四氢呋喃水合物模拟天然气水合物,在天然海砂中模拟其生成分解过程并进行了TDR测试,通过分析水合物生成过程中TDR测试的表观介电常数和电导率动态变化特征、讨论水合物饱和度的影响规律,验证了该测试平台的可靠性。基于理论分析分别建立了基于表观介电常数、电导率以及两者联合的水合物饱和度计算模型,实验数据检验结果表明联合模型的水合物饱和度计算误差最低。[Objective]Dielectric permittivity and electrical conductivity are key parameters for characterizing the electrical properties of hydrate-bearing sediments and predicting hydrate saturation.Thus,petrophysical models based on the two electrical parameters for interpreting the dielectric and resistivity logging data need to be established.However,because of the peculiarity of marine sediments containing gas hydrates,effective petrophysical models for accurately evaluating hydrate saturation are lacking.Considering the high cost of obtaining real hydrate-bearing sediment samples from field drilling,researchers usually conduct simulation experiments in the laboratory to prepare hydrate-bearing samples and perform electrical tests.Time-domain reflectometry(TDR)has the advantage that both permittivity and conductivity can be derived from TDR responses.However,traditional TDR probes cannot be used in high-conductivity marine sediments because of the high attenuation of electromagnetic signals along the probe rods.Thus,the development of new TDR probes applicable to hydrate-bearing marine sediments with high porewater salinity is of great significance.[Methods]First,a new type of probe,called a segmented coating TDR probe,was designed.Then,a testing platform for hydrate simulation experiments in marine sediments and TDR testing was developed.To derive the permittivity and conductivity from the TDR responses,the TDR probe parameters,such as the real length of rods and geometric factor,were determined based on standard calibration tests.To correct the impacts of the segmented coatings on the derived electrical parameters,two groups of tests were designed and conducted.One group of tests was performed on standard materials with permittivity from 1 to 80,including air,ethanol,ethylene glycol,and deionized water.The other group of tests was performed on sodium chloride aqueous solutions with mass fractions up to 4%.Correction models were established based on the regression between the permittivity and conductivity derived fro

关 键 词：天然气水合物 测试平台 时域反射技术 分段涂层探头 电学模型 

分 类 号：N33[自然科学总论] P618.13[天文地球—矿床学]