Numerical Model for Interpretation of Distributed Temperature Sensor Data During Hydraulic Fracturing

Abstract

Abstract Injection of cold fluids into tight gas formation during hydraulic fracturing results in cooling of the formation around the fracture and the wellbore. Fluid leakoff from the fracture causes a non-uniform temperature distribution around the fractured zone. Subsequently, during the shut-in period, the near fracture region warms up due to heat flux from the external reservoir rock. Thus, the near wellbore region is subjected to cooling and then warm back which can be measured by the use of distributed temperature sensors (DTS). In this study we develop a numerical model to calculate the temperature during both hydraulic fracturing and the shut in period. The numerical model solutions can be used to interpret field data from the DTS during hydraulic fracturing, to estimate the fracture length, and when coupled with a wellbore model, to quantify the total volume of fracturing fluid injected into an interval. Additionally, the model developed can be used in a temperature history matching algorithm to obtain characteristics of the hydraulic fracture. The models are validated using analytical limiting case solutions.