Abstract:

Fracture conductivity directly influences productivity of fractured formation and is an important index for evaluation of fracturing. This paper analyzes the prerequisites and methods to calculate conductivity of hydraulic fractures through transient test. Taking Xinchang gasfield in Sichuan basin as an example,using partial correlation method,formation and operational parameters that influence conductivity of hydraulic fractures including formation thickness,interval transit time, shale content, proppant content, pump output and preflush volume are optimized.GM(1,h) gray model is introduced to increase the accuracy of conductivity prediction.This method can also be used to predict fracture half-length and production gain factor. The prediction accuracy of production gain factor, however, is poor due to the influences of unpredictable factors such as skin.Therefore fracture conductivity is relatively suitable for evaluation of fracturing effects.

Key words: hydraulic fracturing, evaluation of effects, transient test, partial correlation, gray model