Prediction of Hydrostatic Pressure and Downhole Mud Temperatures While Drilling


Drilling fluids
deep wells
bottom hole temperature
hydrostatic pressure
circulating temperature

How to Cite

I. M. Kutasov, L. V. Eppelbaum. Prediction of Hydrostatic Pressure and Downhole Mud Temperatures While Drilling. Int. J. Petrol. Technol. [Internet]. 2016Mar.1 [cited 2022Jan.28];2(2):53-7. Available from:


In deep and hot wells, the densities of water/oil muds and brines (geofluids) can be significantly different from those measured at surface conditions. As a result, bottom-hole pressures predicted with constant mud densities can be in error by hundreds of psig. Determining accurate the density of drilling mud (the density of the formation fluids) under downhole conditions needs for calculating the actual hydrostatic pressure in a well and predicting differential pressure at the bottom-hole. This will help to reduce the fluid losses resulting from miscalculated pressure differentials. In areas with high geothermal gradients, the thermal expansion of drilling muds can lead to unintentional underbalance, and a kick may occur. In this paper we demonstrate the use of an empirical equation for the downhole circulating mud temperature as well as the early derived analytical equation for the drilling mud hydrostatic pressure. A field example is presented.


Covan M and Sabins F. New Correlations Improve Temperature Predictions for Cementing and Squeezing. Oil and Gas Journal 1995; 21: 53-58.

API RP 10B, Recommended Practice for Testing Well Cements. Washington, DC, 22nd Edition 1997.

Kutasov IM. Method Corrects API Bottomhole Circulating- Temperature Correlation. Oil and Gas Journal 2002 July 15.

García A, Ascencio F, Espinosa-Paredes G, Santoyo E, Gutiérrez H and Arellano VA. Numerical modeling of hightemperature deep wells in the Cerro Prieto geothermal field, México. Geofísica Internacional 1999; 38(4): 251-260.

Kutasov IM. Applied Geothermics for Petroleum Engineers. Elsevier, Amsterdam, 1999: pp. 1-347.

Kutasov IM and Sweetman M. Method Predicts Equivalent Mud Density for HPHT Wells. Oil and Gas Journal 2001; 24: 57-62.

Eppelbaum LV, Kutasov IM and Pilchin AN. Applied Geothermics. Springer, Berlin – Heidelberg – London 2014; pp. 1-751.

Kutasov IM and Eppelbaum LV. Pressure and Temperature Well Testing. CRC Press (Taylor and Francis Inc) 2015; USA: pp. 1-276.

García A, Hernández I, Espinosa-Paredes G and Santoyo E. TEMLOPI: A thermal simulator for estimation of drilling mud and formation temperatures during drilling of geothermal wells. Computers and Geosciences 1998; 24(5): 465-477.

Espinosa-Paredes G, García A, Santoyo E and Hernández I. TEMLOPI/V.2: A computer program for estimation of fully transient temperatures in geothermal wells during circulation and shut-in. Computers and Geosciences 2001; 27(3): 327-344.

Santoyo E, Santoyo S, García A, Espinosa Paredes G and Moya SL. Rheological property measurement of drilling fluids used in geothermal wells. Applied Thermal Engineering Jour 2001; 21(3): 283-302.

Espinosa-Paredes G, Morales-Díaz A, Ulea-González U and Ambriz-García JJ. Application of a proportional-integral control for the estimation of static formation temperatures in oil wells. Marine and Petroleum Geology 2009; 26: 259-268.

Kuliyev SM, Esman BI and Gabuzov GG. Temperature Regime of the Drilling Wells, Nedra, Moscow (in Russian) 1968.

Kutasov IM, Caruthers RM, Targhi AK and Chaaban HM. Prediction of Downhole Circulating and Shut-in Temperatures. Geothermics 1988; 17(4): 607-618.

Kutasov IM. Empirical Correlation Determines Downhole Mud Density. Oil and Gas Journal 1988; 61-63.

Wooley GR, Giussani AP, Galate JW and Wederlich HF. III Cementing Temperatures for Deep-Well Production Liners. SPE paper 13046, presented at the 59th Annual Techn Conf and Exhib. Houston, Texas 1984; 16-19.

McMordie WC Jr, Bland RG and Hauser JM. Effect of Temperature and Pressure on the Density of Drilling Fluids. SPE Paper 11114, presented at the 57th Annual Techn Conf and Exhib of the SPE, New Orleans 1982; 26-29.

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.