The correction of linear fracture density and error analysis using underground well-logging data

Abstract

Fractures are favorable fluid channels and provide storage space in reservoirs, which are of great significance to the exploration and development of groundwater, petroleum, etc. Quantitative analysis of fracture density controlled by mechanical stratigraphy is of great importance to determine or predict fracture properties and statistics in a reservoir. The measurement of subsurface fracture parameters is usually limited to observations from drill cores. The semi-one dimensional drill core data require corrections, in particular the Terzaghi correction for orientation bias. The Terzaghi correction performs poorly when the angle between drill core and fractures is small. To correct this, we suggest extending Terzaghi’s correction to include the diameter of the drill core. The new correction method reduces the correction error. It is particularly useful when bedding thickness is small, and fracture density is large. This study thus proposed an extension to Terzaghi’s method to correct orientation bias in the quantification of linear fracture density, especially applicable to thin layers or large fracture densities. Note: This paper was accepted into the Technical Program but was not presented at IMAGE 2022 in Houston, Texas.