As interest in exploiting shale gas/oil reservoirs with multiple stage fractured horizontal wells increased, complexity of production analysis and reservoir description have also increased. The main objective of this paper is to present and demonstrate type curves for production data analysis of shale gas/oil wells using a Dual Porosity model.
Dual Porosity model is based on Bello and Wattenbarger’s (2010) mathematical model where hydraulic fractures act as a secondary porosity system where matrix is the primary porosity system. Samandarli et al. (2011) showed application of this model on history matching and forecasting of shale gas wells with multiple fractures by doing regression on effective fracture and matrix permeability and half length. This type of regression is as rigorous as simulation, however much faster than it. On the other hand for "quick look interpretation" having type curves will make the production analysis even more convenient for practical purposes.
With this method production of shale gas/oil well can be matched with developed type curves which vary with effective permeability. Once the production data is matched with one of the type curves, effective permeability and match points are recorded. By using dimensionless equations developed for Dual Porosity model fracture half-length can be determined. In order to use type curves, good estimate for effective porosity and matrix permeability should be predetermined.
Type curves developed in this paper were applied to synthetic and field data examples. Early results show that method works well in determining effective fracture half-length which is the most important parameter in evaluation of stimulated reservoir volume (SRV).