Analysis of Reserve Recovery Potential from Hydraulic Fracture Reorientation in Tight Gas Lenticular Reservoirs

摘要

The basic concept of hydraulic fracture reorientation involves inducing a second artificial fracture into the producing zone,with this secondary fracture propagating in a different direction from the original.For reorientation to occur,the near wellbore stress has to have altered in orientation from the time the original fracture was created.To investigate the effects of this action on reserve recoveries in tight gas lenticular reservoirs,a series of simulations were run in a reservoir modeling program where orientation was assumed to occur at various given angles.The reservoir and fracture properties that were manipulated in order to run the model under different scenarios included the following:fracture orientation,fracture half- length,fracture conductivity,reservoir area,permeability anisotropy,and geologic aspect ratios.For each scenario,production of the field was then simulated over a period of time to study sensitivities of the parameters.The research presented in this paper led to the following main conclusions:1) refracture reorientation can be effectively studied using a reservoir simulator through manipulation of the fracture and reservoir parameters over time;2) incremental gains in production and pressure responses were observed with the variance of these various reservoir and fracture properties that were consistent with the possibility of hydraulic fracture reorientation;and 3) results indicate that even assuming refracture reorientation is possible,it would not be economical under typical conditions in most tight gas lenticular reservoirs due to their limited volumes.