In-situ thermal rheological properties of drilling muds

Ali Ettehadi, Izmir Katip, Gursat Altun

Research output: Contribution to conferencePaperpeer-review

4 Citations (Scopus)


Thermal rheological properties of three drilling fluids suggested for hot environments were experimentally investigated using both HTHP dynamic rheometer and classical viscometer. Two of them were polymer based muds commercially used in geothermal drilling, and the third one was sepiolite base mud prepared with specially mixing order in this study. Rheological measurements at six different shear rates were performed in a programmed temperature range of 100 to 500°F with 10°F increments at a 700 psi of pressure differential. Flow characteristics of sample muds in a given well geometry were also considered using a numerical application. Two polymeric muds sampled from a geothermal field in Turkey exhibited very low viscosity with a low thermal viscosity variation interval at temperatures above 300°F. In contrary, the sepiolite mud demonstrated higher viscosity and kept its stability with increasing temperatures up to 500°F. Findings also indicated remarkable viscosity differences between the conventional viscometer and the dynamic HTHP rheometer. Hydraulic optimization in terms of circulation pressure losses, cutting transport, and surge and swab pressures were numerically modelled. Optimization results based on conventional viscometer measurements generated noticeable errors causing difficulties through drilling program. Numerical application revealed that the usage of improper viscosity values resulted in calculation of well design parameters beyond the safe drilling limits. Through this study, it was revealed that sepiolite based muds could be good candidate for drilling hot and/ or hostile wells such as deep oil and gas wells, geothermal wells, and drilling through high saline formations. As excessive temperature through wellbore can lead to serious well problems, selecting thermally stable mud with proper rheological properties to improve penetration rates, hole cleaning properties, and borehole integrity can clearly express the importance of this study.

Original languageEnglish
Publication statusPublished - 2018
EventSPE/IADC Middle East Drilling Technology Conference and Exhibition 2018 - Abu Dhabi, United Arab Emirates
Duration: 29 Jan 201831 Jan 2018


ConferenceSPE/IADC Middle East Drilling Technology Conference and Exhibition 2018
Country/TerritoryUnited Arab Emirates
CityAbu Dhabi

Bibliographical note

Publisher Copyright:
Copyright 2018, SPE/IADC Middle East Drilling Technology Conference and Exhibition.


Dive into the research topics of 'In-situ thermal rheological properties of drilling muds'. Together they form a unique fingerprint.

Cite this