浅层地下流体保真取样技术及工程应用

开展地下流体取样作为地下环境保护的基础性工作，是实现地下能源可持续发展的关键性措施。通过对比国内外地下流体取样技术，气体推动式取样技术具有取样精度高、地层扰动小、分层连续取样的特点，是实现地下环境三维高精度连续监测的重要技术手段。通过分析国外气体推动式取样器的结构及应用情况，研发了浅层U形管分层取样系统，通过定制连接构件、封隔器、过滤渗析组件及储流容器，克服了应用深度有限、层间封隔性弱、易淤堵、场地适应性弱等难题，实现了定量、保压取样功能，并使得取样器更加标准化和规范化。目前，取样器在延长油田CCS-EOR示范项目进行安装应用，监测结果证明示范区未发生CO₂泄漏。此外，该应用也验证了所研发的取样系统具有取样精度高、系统体积小、综合成本低等技术优势。通过搭接现场原位监测技术，浅层U形管分层取样装置可望形成地下流体环境实时监测预警平台，为中国地下水资源调查与评估、污染场地监测与修复、废弃物地质封存等环境工程领域提供技术支撑。

Truth-preserving Sampling Technology for Shallow Subsurface Fluid and Engineering Application

Underground fluid sampling is a basic work of underground environment protection and is also the key measurement to realize the sustainable development of underground energy. By comparing to the sampling technology at home and abroad, the gas-operated sampling technology is characterized by high sampling accuracy, small formation disturbance and continuous stratified sampling. Thus, it is possible to realize the three-dimensional high-precision continuous monitoring for underground environment. By analyzing the foreign gas-operated sampling system, we developed a stratified U-tube sampling system. By custom-made link component, packer, filter and fluid container, the The U-tube sampling system had overcome the problems of limited application depth, weak interlayer isolation, siltation, and field adaptability and so on. In addition, the functions of quantitative and truth-preserving sampling had also been realized, which made the U-tube samplers to be more standardization and specifications. The samplers had been applied in the CCS-EOR demonstration project of Yanchang oilfiled, China. The test results show that there is no CO2 leakage around the demonstration area. In addition, the performance of high sampling accuracy, small volume and low cost were proved to be effective. By integrating the in-situ monitoring technology, the shallow U-tube stratified samplers are expected to be a real-time monitoring and warning platform for the underground environment, providing technical supports in the environmental engineering fields, such as investigation and evaluation of groundwater resources, monitoring and remediation of contaminated sites, geological storage of wastes and so on.