Analysis for formation thermal properties of water injection well from temperature data

Formation thermal properties are important parameters for evaluating thermal recovery. This study uses a special layered inversion method appropriate to water injection well to estimate the formation thermal properties profiles from temperature log data. The proposed method is based on the water temperature model. Therefore, a novel heat transfer model for water injection well was built firstly to get the temperature model. Then sensitivity analysis was conducted to investigate the correlation between the thermal properties and water temperature, determining estimation sequence. With applying the inversion method to predict the formation thermal properties of three water injection wells, the thermal properties profiles which reflect the differences in physical properties of geological formations were obtained. The sensitivity analysis concludes that heat capacity showed stronger correlation with temperature than thermal conductivity, which is contrary to steam injection well sensitivity result. Based on the sensitivity analysis, heat capacity is estimated firstly bringing higher precision for water injection well thermal properties estimation. And the prediction precision of heat capacity is higher than that of thermal conductivity, also demonstrating the accordance of the proposed method for water injection well. Above all, thermal properties acquired by the layered inversion method show depth-variant in whole formation.