Kinematic instabilities in two-layer eccentric annular flows, part 2: shear-thinning and yield-stress effects

Abstract

Abstract. This paper investigates the possibility of kinematic interfacial instabilities occurring during the industrial process of primary cementing of oil and gas wells. This process involves to flows in narrow eccentric annuli that are modelled via a Hele-Shaw approach. The fluids present in primary cementing are strongly non-Newtonian, usually exhibiting shear-thinning behaviour and often with a yield stress. The study is a sequel to [1] in which the base analysis has been developed for the case of 2 Newtonian fluids. The occurrence of static mud channels in primary cementing has been known of since the 1960's, [2], and is a major cause of process failure. We quantify this phenomenon, providing a simple semi-analytic expression for the maximal volume of residual fluid left behind in the annulus, f static , and illustrate the dependency of fstatic on its five dimensionless parameters. We show that 3 of the 4 different types of static channel flows are linearly stable.Via dimensional analysis, we show that the base flows depend on a minimal set of 8 dimensionless parameters and the stability problem depends on an additional 3 dimensionless parameters. This large dimensional parameter space precludes use of the full numerical solution to the stability problem as a predictive tool or for studying the various stability regimes. Instead we have developed a semi-analytical approach based on solution of the long wavelength limit. This stability results can be evaluated via simple quadrature from the base flow and is suitable for use in process optimisation.

A Review of Rheological Modeling of Cement Slurry in Oil Well Applications

“…Finite difference method based on alternating direction implicit technique was applied in this software. Moyers-Gonzalez and Frigaard [277] investigated the kinematic instabilities in two-layer eccentric annular flows during oil and gas well cementing process. A non-Newtonian fluid model with shear-thinning and yield stress, namely the Herschel-Bulkley model, was used.…”

Research on the Modified Model for Steady Displacement Interface Shape in Inclined Wells with Eccentric Annuli

“…By integrating (7) and (8) three times on y, we get: (11) where, the integrand on the right-hand side is zero in an unyielded region of the flow, i.e., η → ∞ in such regions. …”

Microlayer and nanolayer tubing and piping via layer multiplication coextrusion. II. Rheologically mismatched systems

“…Pertaining to purely annular flow instabilities of multilayered polymeric systems, substantial work has been conducted in the areas of core-annular flow [17][18][19][20][21][22][23][24] and eccentric annular flow, [25][26][27] mainly due to interest in oil and gas drilling operations. In the realm of polymer melt flow, little work has been conducted on flow through concentric annuli, due to the geometries' high tolerance of flow instabilities.…”