Wellbore temperature distribution in hydraulic-fracturing horizontal wells for gas

Use of distributed temperature sensors (DTS) to monitor the productive zones of horizontal wellbores by real-time temperature profile measurement is becoming an industry standard. Well completion method, skin factor and non-Darcy flow phenomenon are among operating parameters potentially related to DTS data. In order to study on the above-mentioned relationship, this paper establishes temperature models which consider skin factor and non-Darcy flow, in turn whose foundation are mass-, momentum-, and energy-balance equations. The models presented here account for heat convection, fluid expansion, heat conduction and viscous dissipative heating. Once configured, these models were applied to predict wellbore temperature distribution and analyze factors influencing the wellbore temperature profile. Arriving temperature and wellbore temperature curves are plotted by computed iterative calculation. By analyzing the sensitivity of non-Darcy flow factor and skin factor, we conclude that temperature along the wellbore is related to both factors. Temperature response type curves show that the larger the preset skin factor is, the smaller will be the resulting wellbore temperature. In addition, greater non-Darcy flow factor may generate greater decrease in temperature along the wellbore. Thirdly, varying well completion methods show different temperature distributions along the wellbore. These observations indicate that this model provides an alternative perspective for description of downhole physical characteristics in hydraulic fracturing horizontal wells.