Development and field testing of a shallow multiphase in-situ sampler

Abstract:

To address the limitations of existing shallow sampling techniques， such as limited sampling depth， low sample recovery rate， high operational costs， restricted accessibility due to heavy equipment， and the inability to simultaneously collect undisturbed soil and fluid samples， a shallow multiphase in-situ sampler was developed with the design objectives of "low disturbance， high efficiency， and multiphase synchronization." This sampler employs a combined process of "dual-tube drilling for soil sampling and vacuum suction for fluid sampling." Through structural optimization and functional integration of key components， including the sampling bit， soil inner tube， fluid sampler， and sealing airbag， the device achieves synchronous and efficient collection of shallow undisturbed soil samples and in-situ water （gas） samples. Additionally， the extraction resistance of the casing was analyzed， and a corresponding lightweight casing lifting tool was developed. Field test results indicate that the sampler achieved an average soil sample recovery rate of 75% within a depth of 5 m， successfully performed simultaneous collection of in-situ water （gas） samples， and ensured no sample cross-contamination or leakage. Featuring a lightweight structure， simple operation， and low cost， the sampler is suitable for shallow sampling operations in confined spaces or areas inaccessible to heavy equipment， providing a reliable technical means for collaborative sampling of shallow multiphase media.