Performance Prediction of Multi-Fractured Horizontal Wells in Shale Gas Condensate Reservoirs Using Flowback Rate Transient Analysis

Flowback data following hydraulic fracturing (HF) provide crucial insights into HF characteristics through rate transient analysis (RTA). However, most flowback RTA methods for shale gas reservoirs overlook the effects of condensate dropout. In this study, we developed a two-dimensional (2D) three-phase flowback model with the three-phase influx that captures the two primary flow regimes: infinite-acting linear flow (IALF) and boundary-dominated flow (BDF). The model considers three-phase water, gas, and condensate (oil) flow from the matrix to the fracture and from fracture to wellbore. This model analyzes flowback data during HF depletion, even in the presence of condensate dropout. To enhance its analytical capability, we revised the Walsh material balance equation to estimate the average HF pressure and redefined the pseudo-variables to generate diagnostic plots for flow regime identification, along with specialized plots for HF characterization. We validated our proposed iterative processes against numerical simulations. Our three-phase flow models' estimated half-length and initial HF permeability closely matched the numerical model's set values, with relative errors below 10%. These results demonstrate that the proposed three-phase flowback model significantly improves our understanding of early HF dynamics and the initial behavior of condensate within the HF system and surrounding matrix.