Determination of formation temperature from bottom-hole temperature logs-a generalized Horner method

Abstract

A new technique has been developed for the determination of the formation temperature from bottom-hole temperature logs. The adjusted circulation time concept, and a semi-analytical equation for the dimensionless temperature at the wall of an infinite long cylindrical source with a constant heat flow rate, is used to obtain the working formula. It is shown that the transient shut-in temperature is a function of the mud circulation and shut-in time, formation temperature, thermal diffusivity of formations and well radius. The sensitivity of the predicted values of formation temperature to the thermal diffusivity is shown. Two examples of calculations are presented. © 2005 Nanjing Institute Geophysical Prospecting.