Technique and preliminary application of field analysis of water content for continental shale cores

Abstract

Fluid analysis of continental shale layers plays a crucial role in evaluating shale oil layer selection. Given the current state of technologies of fluid characterization for continental shale layers and well-site requirements, a rapid method for testing water content of rock sample was developed in this study which uses microwave and is ideal for well site. After removing drilling fluid from the core surface, rock samples are promptly collected and crushed into particles using a mill. These granular samples are then placed in the sample cups of a microwave water content tester. Within 2 seconds, mass percentage data for the rock water sample can be obtained, with an average absolute error of ±0.15%. Initial application studies demonstrate promising prospects for moisture detection data in rock samples. Firstly, the water detection results can be used to calculate the pore space occupied by water in the sample's pore system, enabling quick determination of the sample's apparent porosity when combined with well site pyrolysis data. Secondly, the apparent oil saturation and apparent water saturation of core samples can be calculated based on rock sample density and pyrolysis data, facilitating rapid evaluation of rock sample fluids at the well site. This method eliminates the washing and drying processes for rock samples, reduces analysis time, and consequently enhanced the experimental techniques for core porosity and fluid analysis at well sites.

Keywords

• core water content
• apparent oil saturation
• apparent water saturation
• apparent porosity
• continental shale
• well site analysis technology