Influence of measured thermophysical parameters of drilling fluids on downhole temperature models

Abstract

Predicting downhole circulating temperature is essential for successful drilling operations as bottom hole temperature variations are a major cause of changing effective mud density and mud volume. So, the effort is needed for the development of dynamic modeling capability to simulate the complex downhole temperature environment as Thermal conductivity and specific heat capacity of drilling fluid are an important component in temperature modeling. Despite their importance, very limited data in the literature is available on these parameters. Mostly the values of thermal conductivity and specific heat are estimated using generic models.

An experimental study is performed to measure the thermal conductivity and specific heat capacity of the samples of oil-based mud and water-based mud in the laboratory using the C-Therm TCi thermal conductivity analyzer. Based on the measured values models are generated for thermal conductivity and specific heat capacity of drilling fluid which are then implemented in a simulator on two different wells. The results from these models show the difference of 2.5°C to 5°C to in the bottom hole temperature from the generic model for shallow horizontal well and vertical well respectively.