Analysis of Shut-In Pressure Data from Hydraulic Fracturing with Non-Uniform Proppant Distribution

Abstract Evaluation of proppant distribution is of paramount importance for hydraulic fracturing treatment in unconventional resource development. This study aims to develop a pressure drop model after hydraulic fracturing shut-in that accounts for unevenly-distributed proppant migration. By incorporating proppant movement dynamics, the model enables accurate simulation of pressure behavior during shut-in. And field-derived pressure data during fracturing could be used to assess hydraulic fracturing effectiveness and optimizing fracturing design strategies. The reservoir model couples the fracture system and matrix system, which considered horizontal transport of the proppant, driven by viscosity, velocity, and gravitational forces. The model is applied to analyze the impact of proppant distribution on pressure behavior. The model is validated using field data from a multi-stage fractured horizontal well in unconventional reservoirs. By fitting the shut-in pressure drop curves, propped fracture volume and proppant placement uniformity are characterized. Our results reveal that the shut-in pressure drop curve exhibits a distinctive shape. By analyzing the pressure drop derivative curve, we observe that the non-uniform proppant distribution directly influences pressure behavior, with more uniform proppant placement leading to a smoother pressure derivative curve. Field application confirmed the accuracy of the model. Case study also demonstrates that proppant migration significantly affects pressure drop characteristics, offering a reliable approach to evaluating hydraulic fracturing effectiveness and optimizing proppant distribution strategies. This work develops a pressure drop model that uniquely accounts for proppant migration during hydraulic fracturing pump shutdown. The model successfully correlates pressure drop characteristics with proppant placement and is validated using field data from a well with hydraulic fracturing. This advancement enhances hydraulic fracturing evaluation and optimization, providing a new approach to interpreting proppant transport behavior.