Curve-fitting equation for prediction of the start-up stress overshoot of an oil-based drilling fluid

Abstract Drilling fluids usually gel at rest in order to avoid cuttings to precipitate over the drill bit when circulation is interrupted. At flow start-ups, pumping pressures higher than the steady-state circulation pressure are usually required to surpass the gel strength. The gel-liquid transition may have significant importance, especially in ultra-deep waters where high pressures and low temperatures take place. In the current work, controlled shear rate rheometric tests were conducted to investigate the yielding of an oil based drilling fluid. An algebraic equation, that accounts for both shear rate and shear history, is proposed to predict the gel breaking. This equation requires less fitting parameters than the current structural kinetic models available in literature, and is quite useful to represent the pressure peaks that take place during drilling fluid flow start-ups. The equation fit to rheometric data and is able to predict satisfactorily the start-up shear stress of a gelled drilling fluid at different shear rates.

[1]  J. Mewis,et al.  A structural kinetics model for thixotropy , 2006 .

[3]  S. Lerouge,et al.  SHEAR BANDING IN A MICELLAR SOLUTION UNDER TRANSIENT FLOW , 1998 .

[4]  E. Kreyszig,et al.  Advanced Engineering Mathematics. , 1974 .

[5]  A. Teja,et al.  A modified rough hard-sphere model for the viscosity of molten salts , 2016 .

[6]  J. Delegido,et al.  Flow and thixotropy of non-contaminating oil drilling fluids formulated with bentonite and sodium carboxymethyl cellulose , 2007 .

[7]  Philippe Coussot,et al.  Viscosity bifurcation in thixotropic, yielding fluids , 2002 .

[8]  R. Thompson,et al.  Critical quantities on the yielding process of waxy crude oils , 2015, Rheologica Acta.

[9]  David V. Boger,et al.  Yield Stress Measurement for Concentrated Suspensions , 1983 .

[10]  R. Thompson,et al.  A unified approach to model elasto-viscoplastic thixotropic yield-stress materials and apparent yield-stress fluids , 2013, Rheologica Acta.

[11]  R. Ewoldt,et al.  Large amplitude oscillatory shear of pseudoplastic and elastoviscoplastic materials , 2010 .

[12]  Jan Mewis,et al.  Yield stress and thixotropy: on the difficulty of measuring yield stresses in practice. , 2006, Soft matter.

[13]  Roberto Maglione,et al.  Optimal determination of rheological parameters for Herschel-Bulkley drilling fluids and impact on pressure drop, velocity profiles and penetration rates during drilling , 2006 .

[14]  Neil J. Balmforth,et al.  Yielding to Stress: Recent Developments in Viscoplastic Fluid Mechanics , 2014 .

[15]  Philippe Coussot,et al.  Flow instability and shear localization in a drilling mud , 2006 .

[16]  H. Barnes.  Thixotropy—a review , 1997 .

[17]  A. B. Metzner,et al.  Transient phenomena in thixotropic systems , 2002 .

[18]  Q. D. Nguyen,et al.  Measuring the Flow Properties of Yield Stress Fluids , 1992 .

[19]  G. Longo,et al.  Experimental measurement of thermophysical properties of oxide–water nano-fluids down to ice-point , 2011 .

[20]  Cezar O.R. Negrão,et al.  A weakly compressible flow model for the restart of thixotropic drilling fluids , 2011 .

[21]  R. Jain,et al.  Development of Jatropha oil-in-water emulsion drilling mud system , 2016 .

[22]  R. Fernandes,et al.  Correlation between the gel–liquid transition stress and the storage modulus of an oil-based drilling fluid , 2016 .

[23]  H. Rønningsen,et al.  Effect of Precipitated Wax on ViscosityA Model for Predicting Non-Newtonian Viscosity of Crude Oils , 2000 .

[24]  L. Hou.  Experimental study on yield behavior of Daqing crude oil , 2012, Rheologica Acta.

[25]  Larry W. Lake,et al.  Rheological and yield stress measurements of non-Newtonian fluids using a Marsh Funnel , 2011 .

[26]  Jasbir S. Arora,et al.  Introduction to Optimum Design , 1988 .

[27]  V. Kelessidis.  Investigations on the Thixotropy of Bentonite Suspensions , 2008 .

[28]  S. Manneville,et al.  Stress overshoot in a simple yield stress fluid: An extensive study combining rheology and velocimetry , 2011, 1104.4444.

[29]  Marvin A. Tung,et al.  Drilling fluid shear stress overshoot behavior , 1987 .

[30]  Silviu Livescu,et al.  Mathematical modeling of thixotropic drilling mud and crude oil flow in wells and pipelines—A review , 2012 .