Evaluation of the impact of multi-phase flow on reservoir signatures in the Wolfcamp shale

The dominant transient flow regime for multi-fractured horizontal wells (MFHWs) producing from low-permeability and shale (unconventional) reservoirs has historically been interpreted to be transient linear flow (TLF) with analysis performed in the framework of classical diffusion (CD). Recently, observed deviations away from this classical behavior for Permian Basin Wolfcamp shale (oil) wells have been attributed to reservoir heterogeneity and anomalous diffusion (AD). However, some wells in the basin also produce below bubble point pressure and exhibit characteristics of multi-phase flow. The objective of the current study is therefore to investigate if multi-phase flow may also be contributing to observed deviations from classic TLF behavior.