Zipper fracturing is a method of sequencing frac jobs in multi-well pads that helps increase operationalefficiency and reduce stimulation time for a pad.This technique involves stimulating several wells in a padin a prescribed sequence of stages.In this work,we provide a thorough assessment of the various factorsimpacting the effectiveness of zipper fracturing treatments and provide a methodology for selecting anoptimum sequence of fracture stages.A fully implicit,parallelized,3-D,pad-scale reservoir-fracturing simulator is used to simulate thedynamic propagation of multiple,non-planar fractures from multiple treatment wells while capturing thestress interference between fractures.This interference is captured both on an intra-well as well as an inter-well scale.Interaction between fractures propagating from different wells is found to be dependent onpad design,completion design,and reservoir parameters.We evaluate the effectiveness of the stimulationoperation by comparing the impact of operation decisions on the created fracture geometries and simulatedproductivity of the propagated fractures using seamless fracturing-reservoir simulations.The simulation results are used to understand the impact of well spacing,stage spacing,staggering ofzipper-frac wells,lagging of stages during zipper fracturing,size of the frac job,stress contrast in thereservoir and rock properties.Using multi-cluster fracturing simulations and accurate proppant distributioncalculations in the wellbore,we consider the impact of various operational decisions mentioned aboveon the distribution of proppant in the created fractures.We observe that fracture closure during shut-inof a stage impacts the created fracture geometries.This affects the proppant distribution in the fracturedstages.The impact of the operational decisions on the fracture conductivity degradation during stimulationis also captured using seamless fracture-reservoir simulations.We show that the results obtained from thesesimulations can help design pad-scale operations to maximize the fracture-reservoir contact area or improvethe productivity of the wells.In this work,for the first time,we assess the impact of zipper fracturing on well productivity byperforming coupled fracturing-reservoir simulations.The software is used to simulate fracture propagationand fracture closure during shut-in and production.The results obtained from these simulations recommendan optimized fracture sequencing,stage lag and staggering strategy to maximize the productivity of the pad.
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