Sand minimum transport conditions in gas–solid–liquid three-phase stratified flow in a horizontal pipe at low particle concentrations

Abstract

Sand production in the life of oil and gas reservoirs is inevitable, as it is co-produced with oil and gas from the reservoirs. Its deposition in petroleum pipelines poses considerable risk to production and can lead to pipe corrosion and flow assurance challenges. Therefore, it is important that pipe flow conditions are maintained to ensure sand particles are not deposited but in continuous motion with the flow. The combination of minimum gas and liquid velocities that ensure continuous sand motion is known as the minimum transport condition (MTC). This study investigates the effect both of sand particle diameter and concentration on MTC in gas/liquid stratified flow in a horizontal pipeline. We used non-intrusive conductivity sensors for sand detection. These sensors, used for film thickness measurement in gas/liquid flows, was used here for sand detection. We found that MTC increases with increase in particle diameter for the same concentration and also increases as the concentration increases for the same particle diameter. A correlation is proposed for the prediction of sand transport at MTC in air-water flows in horizontal pipes, by including the effect of sand concentration in Thomas's lower model. The correlation accounts for low sand concentrations and gave excellent predictions when compared with the experimental results at MTC.

Sand Transport and Deposition Behaviour in Subsea Pipelines for Flow Assurance

“…Dabirian et al 2016 [30] 45-600 0.025-1% 97 Najmi et al 2016 [31] 20-300 0-1% 50 Najmi et al 2016 [32] 150-300 0.01-0.1% 50-100 Dabirian et al 2018 [33] 150-600 0-1% 50 Dabirian et al 2018 [34] 45-600 0.025-1% 97 Tebowei et al 2018 [35] 255 0.04% 100 Fajemidupe et al 2019 [36] 212-800 0-0.006% 50.4 Leporini et al 2019 [37] 100-1100 0.0065-0.056% 63 Leporini et al 2019 [38] 45-600 0.00161-0.0538 50-100…”

An experimental study on the startup velocity and motion characteristics of sand beds in air–water pipelines

“…However, mechanical desanding requires accurate predictions of the thickness of sand beds. If predicted values are inaccurate, it is easy for a desander to get stuck in a pipe, making the situation worse 10–13 . If the designed production flow rate is above the critical startup velocity of a sand bed, then settled sand will be reduced.…”

“…If predicted values are inaccurate, it is easy for a desander to get stuck in a pipe, making the situation worse. [10][11][12][13] If the designed production flow rate is above the critical startup velocity of a sand bed, then settled sand will be reduced. Therefore, accurately predicting the critical startup speed of a sand bed is of great significance for reducing the formation of sand beds.…”

An Enhanced Model for the prediction of Minimum Transport Conditions in Multiphase Flow Systems

“…This sand is produced because of the unconsolidated nature of most reservoirs from where the oil is produced. Flow assurance and corrosion problems come into play as more sand gets deposited in the pipeline thereby reducing the internal diameter of the pipe and also the possibility of an increase in pressure loss and so on (Fajemidupe et al 2019). The existence of sand in pipelines can also cause both erosion and corrosion problems at a high production rate, as well as the possibilities of high-pressure loss from the deposition of sand at a low flow rate which would require expensive cleaning operations occasionally for optimal production.…”

“…Though there was agreement between the data obtained from SINTEF laboratory, OLGA did not predict the critical velocity well at turbulent conditions. Fajemidupe et al (2019) carried out an experiment on a small-scale rig flowing air, water and sand particles of different diameters and different concentrations. It was shown that there is an increase in the needed critical velocity as the diameter increases as well as the concentration.…”