#
APS March Meeting 2022

## Volume 67, Number 3

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Monday–Friday, March 14–18, 2022;
Chicago

### Session G00: Poster Session I (2pm- 5pm CST)

2:00 PM,
Tuesday, March 15, 2022

Room: McCormick Place Exhibit Hall F1

### Abstract: G00.00360 : Numerical simulation of gas migration in a cement slurry in a wellbore annulus

Abstract

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Presenter:

NDRI A KONAN

(National Energy Technology Laboratory)

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Authors:

NDRI A KONAN

(National Energy Technology Laboratory)

Eilis Rosenbaum

(National Energy Technology Laboratory)

Mehrdad Massoudi

(National Energy Technology Laboratory)

Gas migration in cement slurries is regarded as one of the more serious problems encountered in the wellbore cementing operations, as this results in about 25-30% of the operation failures [Vazquez et al., 2005]. One approach to mitigate the gas migration is to allow enough time for the cement to develop sufficient gel strength, which describes the phase change from the cement slurry to a gel-like material. Cement slurries, in general, exhibit yield stress, which can depend on the shear rate, concentration of the cement particles, etc. [see Tao et al, 2020]. Their rheological properties are also affected by temperature, pressure, etc. [see Banfill, 2006]. To gain a better understanding of the air bubbles' distribution in the well and their sizes, we simulate using CFD approach, 3D flows of a cement slurry in a laboratory scale annulus representative of real wellbore operations with continuous injection of air. The dynamics of the slurry and the air bubbles are modeled using a two-phase approach, where the volume fraction (concentration of the cement particles), mass and linear momentum conservation equations are solved. We assume that the cement suspension can be modeled as (1) a Bingham fluid and (2) a Herschel-Bulkley visco-plastic fluid. Furthermore, (3) the viscous stress of the cement slurry is assumed to exhibit a dependence on the volume fraction and can account for the shear-thinning or shear-thickening behavior of the slurry. The thixotropy effects are neglected. As for the yield stress, we assume that it depends on the volume fraction as well as the ratio of water-to-cement [see Tao et al., (2020)]. These equations are implemented as customized non-Newtonian viscosity libraries and are solved along with the governing equations in the open-source toolbox/library, OpenFOAM. The simulation results are compared with available measurements, and the statistics of the bubble sizes and their distributions are also analyzed and discussed.