Horizontal drilling and multi-stage hydraulic fracturing have made the commercial development of nano-darcy shale resources a success.Although current production volumes are promising but currently published simulation results show single-digit recovery factors under depletion.Such low recovery factors highlight the importance of accurate modeling of fluid flow and well performance for wells draining such resources.In this study,explicit hydraulic fracture modeling based on data from Eagle Ford shale oil window was performed by linking hydraulic fracture design and reservoir simulation softwares.Simulated production profiles of a homogenous simplified profile and an actual conductivity profile generated by hydraulic fracture design software were compared.The amount of fracturing fluid flowback during the first year of production was examined.The effect of unpropped zone conductivity on production performance was also investigated. The modeling results highlight the pitfalls of misrepresenting the hydraulic fracture with a constant conductivity profile.It also emphasizes the importance of appropriately modeling the amount of recovered fracturing fluid by correctly incorporating fracture propagation predicted by hydraulic fracture design software into the flow simulation model. Oil and water production trends for a single hydraulic fracture stage were observed with and without considering fracturing fluid flowback.Results of a single stage hydraulic fracture simulation showed that ignoring flowback overestimated oil recovery by about 17%.Assuming a constant permeability in the hydraulic fracture plane resulted in overestimation of oil recovery by almost 25%.The conductivity of the unpropped zone affects the recovery factor predictions by as high as 10%.For the case investigated,about 25%of the fracturing fluid was recovered during the first 2 months of production.Increasing the shut in time after fracture stimulation from 6 hours to 24 hours resulted in an increase of flowback volume by 5%. This paper addresses the importance of proper modeling hydraulic fracture conductivity in simulation of hydraulically fractured shale wells.It also highlights the importance of the amount and duration of fracturing fluid flowback,and explains how fracturing and fluid flow modeling softwares can be linked for better well performance predictions.
展开▼
