INTERPRETATIVE MODEL OF RADIAL THERMAL LOGGING

A mathematical model of the temperature fi eld of a fl uid moving in a well is presented. It can be used as the basic one for interpreting measurements of radial temperature distributions. The initial problem has been solved on the basis of an exact "on the average" asymptotic method. The analytical solutions that describe the temperature fi elds of a fl uid in a well shaft were obtained with the aid of the Laplace–Carson transformation. It is shown that the zero expansion coeffi cient describes the radius-averaged background values of the temperature fi eld in the well. The expression for the fi rst coeffi cient describes the radial temperature profi les. This means that the proposed interpretative model allows one to carry out fi ltration of useful temperature anomalies of the radial profi le against the background of considerably large global temperature perturbations caused by the fl uid fl ow in the shaft of an operating well and thereby to remove the problems associated with the incorrect realization of inverse problems. Based on numerical calculations, the infl uence of the temperature signal from the bed and of the thermophysical parameters of the fi lling fl uid has been analyzed, and major advantages and disadvantages of the proposed interpretative model have been established.
A mathematical model of the temperature fi eld of a fl uid moving in a well is presented. It can be used as the basic one for interpreting measurements of radial temperature distributions. The initial problem has been solved on the basis of an exact "on the average" asymptotic method. The analytical solutions that describe the temperature fi elds of a fl uid in a well shaft were obtained with the aid of the Laplace–Carson transformation. It is shown that the zero expansion coeffi cient describes the radius-averaged background values of the temperature fi eld in the well. The expression for the fi rst coeffi cient describes the radial temperature profi les. This means that the proposed interpretative model allows one to carry out fi ltration of useful temperature anomalies of the radial profi le against the background of considerably large global temperature perturbations caused by the fl uid fl ow in the shaft of an operating well and thereby to remove the problems associated with the incorrect realization of inverse problems. Based on numerical calculations, the infl uence of the temperature signal from the bed and of the thermophysical parameters of the fi lling fl uid has been analyzed, and major advantages and disadvantages of the proposed interpretative model have been established.
Author:  A. I. Filippova, E. P. Shcheglova
Keywords:  well, temperature fi eld, Laplace–Carson transformation, radial thermal logging
Page:  720 -729