USING TEMPERATURE MEASUREMENTS FROM PRODUCTION LOGGING/DOWNHOLE SENSORS TO DIAGNOSE MULTISTAGE FRACTURED WELL FLOW PROFILE

摘要

The temperature log as a part of a production loggingpackage has been used in the industry for many years.Recent developments in downhole fiber optic sensingtechnology introduced a more continuousmeasurement of temperature both temporally andspatially for flow diagnosis. One of the powerfulapplications of temperature measurements is todiagnose multistage fracture treatments. Because thefiber optic temperature measurements can be availableduring fracturing, during shut-in, and duringproduction, the integrated interpretation providesinformation of fracture/flow distribution. Thisinformation helps to understand what happenedduring fracture treatments, to identify problems intreatment design and execution, and to improve theefficiency of multistage fracture stimulation.The key component of fracturing diagnosis bytemperature measurements is the interpretationmodels. In this paper, we present the modelsdeveloped for fracture diagnosis. The mathematicalmodels are built on mass, momentum and energyconservation of each component (reservoir, fracture,well completion and wellbore) in the system, and thecomponents are linked through the boundaryconditions. All models can be solved numerically, butfor computational efficiency, analytical/semianalyticalsolutions are preferred when available. Tocorrectly simulate heat transfer during fracturepropagation, a fracture geometry model withappropriate leak off description is integrated into themodel buildup. For flow problem in a fractured well,analytical model, streamline approach and reservoirsimulation can all be the solution methods. The papercompares the advantages of each approach.Field cases from the Eagle Ford and the Marcellusshale formations are presented in the paper to illustratehow the models can be used to generate thefracture/flow distribution. The results show thattemperature measurement is a comprehensive tool forfracture diagnosis.