A new method for determining the formation temperature from bottom-hole temperature logs

I. M. Kutasov¹ and L. V. Eppelbaum²*

¹Pajarito Enterprises, 640 Alta Vista, Suite 124, Santa Fe, New Mexico 87505, USA.

²Department of Geophysics and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel.

*Corresponding author. E-mail: levap@post.tau.ac.il. Fax: +972 3 6409282.

Accepted 27 January, 2010

   Abstract

Earlier, the authors proposed a new method for prediction of formation temperatures in permafrost regions from temperature logs in deep wells, and developed working formulas to process field data. The application of the proposed method on predicting the undisturbed formation temperature does not depend: (a) on the well drilling history (vertical depth versus time and stops in mud circulation), (b) on the knowledge of thermal diffusivity of formations and well radius. This method is based on using only three values of shut-in temperatures. Our investigation indicates that for bottom-hole temperature (BHT) tests, where the thermal disturbance of formations is caused mainly by one short (3-24 hours) continuous drilling fluid circulation period, the developed earlier method can be utilized for processing results of BHT surveys. The results of bottom-hole temperature surveys in three wells and data for one simulated example were used to validate our proposal. We suggest that application of this procedure in oil and gas industry will increase the reliability of temperature field BHT tests.

Key words: Formation temperature, bottom-hole temperature logs, generalized Horner method, oil and gas industry.