Evaluation of the Curve-Fitting Method and the Horner-Plot Method for Estimationof the True Formation Temperature using Temperature Recovery Logging Data

Abstract

TThis paper describes the method to estimate the true formation temperature using temperature recovery logging data after the well reach to total depth (T.D.). The method designated as "Curve-fitting method (CFM)" is based on mathematical model proposed by Middleton (1979, 1982). The accuracy and applicability of this method are evaluated with several field data and compared advantageously with the Hornerplot method. Then, real-time data acquisition system including interpretation software has also been successfully developed. As a conclusion, the followings are confirmed: 1) The developed CFM can be applicable to the estimation of the true formation temperature even using 24 hours temperature recovery data, although the Horner-plot method might need up to 120 hours recovery data, usually. 2) Though depending upon the quality of the data and/or number of the temperature recovery logging data, it might be possible to estimate the true formation temperature using less than 24 hours recovery data. Because, the computer program of this system has the function to decide when the measurement of temperature recovery logging should be finished.