Analysis of the scaling mechanism and characteristics of a double-defects screen based on data from Hafaya oilfield

Corrosion defects of screen occurred frequently in sand control process due to the influence of formation factors. The main purpose of this study was to analyze screen scaling based on field data with CFD technology under different sizes, quantities and distribution modes of corrosion defects. A full presentation of turbulent Kinetic Energy contours, wall shear stress contours, fluid velocity and temperature on the screen surface are presented and discussed in the process of scaling. The distribution characteristics of CaCO3 in the scaling model were used to characterize the scaling characteristics. Furthermore, prediction model of scaling thickness was established to systematically evaluate the results. The conclusion of numerical analysis showed that with other conditions unchanged, the scale of radial distribution is larger than that of axial distribution. More over, the larger the defect width and distance, the less obvious scaling. However, the defect depth indicated the opposite results, which meant that the size factor has the greatest influence on scaling. Keeping the environmental conditions changed, velocity and temperature showed obvious influence on particle scaling. It reveals that the velocity of produced liquid has a great influence on the defect screen with different distribution modes. When the size condition of the defect were kept remained, the scaling amount of screen increases obviously with the increase of velocity. The influence of temperature on the two different distribution patterns of defects was not obvious. With the increased of the temperature, the amount of scaling in the pipe also increased similarly. Considering the results, this research could be used as basis to offer safe operating guidelines to reduce the scaling in the screen due to corrosion defects in oil production. To mitigate the impact of this factor on production, scaling can be addressed by reasonably increasing the velocity of the produced liquid and lowering the temperature with the defects exist.

Automated summary

This study analyzed screen scaling under different sizes, quantities, and distribution modes of corrosion defects using CFD technology. The results showed that the size factor had the greatest influence on scaling, while velocity and temperature also had significant effects. The research can provide safe operating guidelines to reduce scaling.