Pressure and Temperature Transient Analysis: Hydraulic Fractured Well Application

Abstract

Abstract Recent developments in bottomhole data acquisition techniques, such as distributed temperature sensing systems (DTS), have brought attention to the potential increase of information that can be obtained from temperature data. Studies have shown the application of temperature surveys to estimate flowrate profiles, resolve the kind of damage around the well, improve the robustness of the history matching, among others. Nonetheless, Temperature Transient Analysis (TTA) is not a mature technique and its capabilities have not been explored fully yet. In order to investigate the application of temperature analysis to the hydraulic fracturing problem, in addition to pressure analysis, a numerical model was developed to calculate pressure and temperature responses. Regarding the fracture and reservoir fluid flow, a general approach can be adopted, where the formation permeability and fracture characteristics dictate how the fluids flow during and after fracture growth. We developed a comprehensive model, which accounts for the pressure effect on the temperature response, as well as a dynamic fracture that grows and eventually is allowed to close during falloff. In this research we analyzed the temperature and pressure responses during and immediately after hydraulic fracturing in order to improve our knowledge of this complicated physical problem. Based on this study, we can better understand not only the fracture properties, but also the reservoir itself. In addition, sensitivity analysis shows how reservoir permeability can impact final fracturing performance, as well as pressure and temperature responses. The developed model is also applied to simulate minifrac analysis, and a field example is presented that shows a good agreement with the simulated behavior during fracture closure. This paper highlights the potential of Temperature Transient Analysis, expanding the application of temperature in addition to pressure transient analysis to improve the characterization of fractured wells: TTA has potential to reduce uncertainty related to fracture length and reservoir permeability. TTA also adds value to DTS information, which is commonly measured but often not fully used. Temperature analysis has the potential to give reliable information about the flow dynamics of the reservoir and especially about near well zone.