Title: Advanced calculation method for rheological characterisation of non-Newtonian drilling fluids using Herschel-Bulkley model

Authors: Can Polat

Addresses: Petroleum and Natural Gas Engineering Department, Izmir Katip Celebi University, Cigli Main Campus, Science and Engineering Building, 35620, Cigli, Izmir, Turkey

Abstract: Determining Herschel-Bulkley model coefficients from rotational viscometers can be a challenging process. The variation of shear rates according to the rheological model type may bring uncertainty in the regression process evaluated for the estimation of the model coefficients. In this study, the derivation of the equation required for proper determination of the Herschel-Bulkley model coefficients is presented. The derivation process in question revealed the dependence on the Gaussian hypergeometric function. Attempts to determine all coefficients by means of the derived equation appear to yield unrealistic yield points. In this respect, yield point was estimated priorly using Bingham plastic model which was formulated using low speed/dial reading values. The method employed for parameter estimation additionally covers the solution for the not fully developed flow that occurs at low rotational speeds. The accuracy of the proposed method is demonstrated by making comparison with the measured frictional pressure loss data. [Received: September 24, 2023; Accepted: December 24, 2023]

Keywords: Herschel Bulkley model; non-Newtonian drilling fluids; rheological characterisation; Gaussian hypergeometric function; advanced calculation; rotational viscometer; rheological model; yield point.

DOI: 10.1504/IJOGCT.2024.138693

International Journal of Oil, Gas and Coal Technology, 2024 Vol.35 No.4, pp.366 - 385

Received: 21 Sep 2023
Accepted: 24 Dec 2023
Published online: 24 May 2024 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article