Abstract
It is very important to predict well performance of unconventional reservoirs before designing a field development plan. Although these reservoirs have high initial production rates, it is common that their production performance decline faster than conventional reservoirs. Therefore, it is necessary to identify the reasons behind the reduction of production performance. One of these reasons is the increase in stress as a result of continuing production and decrease in pore pressure.
The main objective of the research presented in this paper is to model the effects of stress-dependent permeability for both hydraulic and natural fractures on the production performance of shale gas reservoirs. We generate a new stress-dependent compaction table to history match the performances of a single well in Haynesville formation. We also investigate the optimum operation conditions at which no sever reduction in production performance occurs.
The results of more than 50 simulation cases indicate that stress-dependent properties (permeability and porosity) have a significant effect on reservoir performance. The study also indicate that hydraulic fractures lose over 90% of its permeability with most of the permeability loss occurring at late time of production. The study also shows that we can delay the effect of stress-dependent properties by either increasing initial hydraulic fracture conductivity or operating wells at low drawdown pressure.
