Flowback Study of Hydraulic Fracturing in Shale Gas Reservoirs

Guicheng (Gary) Jing


In this work, a mathematical model was built for optimizing a choke size as wellhead pressure changes over time.  The maximum flowing velocity of a fluid is identified considering the forces acting on proppant particles.  The equations for a pressure drop in two-phase (gas + liquid) flow are derived considering a gas slippage effect and friction loss along horizontal, slanted and vertical paths. The workflow of hydraulic fracturing and fracture cleanup are investigated, which is designed in the interface and functions of the novel simulator.  The new simulator is successfully developed via writing the code with C++ language and realizing the interface with QT.  A novel simulator testing procedure is applied to a shale gas well from the Shuangyang Formation in China. In the exported data, the wellhead pressure, choke size, cumulative fluid production, cumulative gas production, cumulative filtration and flowback rate are demonstrated following each time step in the simulation over time.