The development of shale micro nano-scale fractures and the relationship between its influencing factors and the micro-fracture space

Abstract

To explore the development and influence factors of shale micro-fractures, we used SEM and AFM to observe the shale samples of JY1 well. There are some factors from these pictures: the surfaces of JY1 well are ups and downs; the difference is up to micron level; the micro-fractures connected widely. These expand the reservoir space and storage shale gas. X-ray measured and analyzed mineral composition content of JY1 well, and its brittle mineral content is more than 70%, which it makes the development of micro-fractures good. Many AFM images were processed by the MATLAB software with the integral method. The ratio was calculated of effective volume of micro-fractures to actual shale volume (Percentage of micro-fractures for short). There is a good positive correlations relationship between BET, TOC, desorbed gas and organic pore with percentage of micro-fractures.