Fracture Porosity Calculation Based on Imaging Logging with Images Processing for Gas-bearing Shale

摘要

We introduced the image processing application to identify fracture and calculate fracture porosity based on the image logging for the gas-bearing shale. Shale gas is an unconventional gas resource and has been paid more attention in recent years. The pore structure of shale is very complicated, where fracture is the main flowing channel. The conventional logging and the imaging logging offer the abundant information for formation evaluation in downhole. The dual laterolog logging is used to identify fracture, but difficult to get accurate fracture porosity. The imaging logging could directly characterize fracture in the borehole and easily estimate fracture porosity with images processing method. The image logging processing with the mathematical morphology to calculate the fracture porosity was discussed in the paper. A typical shale gas well Jiaoyel from Jiaoshiba area of Chongqing City in Sichuan Basin was presented to compare the calculation result of the two methods. The results shows that both the dual laterolog logging and the image logging could identify borehole fracture and calculate fracture porosity, where the dual laterolog logging has relatively large uncertainty. The advantage of the imaging logging clearly indicates borehole fracture, but the image processing method should be improved.