Objectives/Scope

The Butler Analytical model has been used to predict steam flood performance using Steam Assisted Gravity Drainage (SAGD). In this paper we apply the Butler Analytical model to three pairs of deviated wells in a steeply dipping heavy oil reservoir.

Methods, Procedures, Process

Simulation studies were carried out on a 100ft thick heavy oil sand with 12 degree API crude for three pairs of parallel deviated wells in a dipping reservoir, situated perpendicular to the 40 degree incline of the reservoir. The results of the simulations study were compared to the production profile predicted by the Butler Analytical Model.

Results, Observations, Conclusions

Both the simulation results and the Butler Analytical Model predict a production profile with two production peaks. The results of the three pairs of parallel deviated wells show the effect of dip and well placement on oil recovery (average 53%) and water production. The major factors influencing the formation of the steam chamber and oil production are reservoir heterogeneity, steam override and well placement. Overall, cumulative production values obtained from the Butler analytical model were less than those from the simulation but the production profiles were comparable. The main difference is due to the advantage of optimal well placement which the Butler analytical model does not take into account. Our results show that the downdip positioning of wells increased oil production. The results of this study are then more closely aligned with the findings of Ramjohn (2014) than Andarcia et al (2014), which concluded that SAGD, (modified for dipping reservoirs), can be effective with optimal well positioning.

Novel/Additive Information

The work presented in this study shows that the Butler Model can be used to predict steamflood performance in deviated wells to recover heavy oil from dipping reservoirs.

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