Nursultan Bakyt (Master of Science in Petroleum Engineering)
Modeling Sand Transportation in Wells under Different Multiphase Flow Conditions
Conclusions and recommendations
Sand particles can be produced from the reservoirs along with oil, water, and gas in the petroleum industry. Particles can cause serious flow assurance issues, blocking a fluid path and causing fluctuations in oil and gas production and transportation system. Studies have been conducted to identify critical particle transport velocity in horizontal stratified flow. However, very little has been done to identify critical particle transport velocity for different inclination angles and flow patterns in the oil and gas production system. In this study, two mechanistic and three empirical models are selected, modified, developed, and presented for stratified, slug, bubbly, dispersed bubble, and annular flow patterns. A model for particle transport in gas production well is also presented. Zhang et al. (2003) unified gas-liquid pipe flow model is applied to cover all inclination angles to determine flow pattern, liquid holdup, and other flow conditions.
Particle transport in a production system is controlled by many parameters like fluid properties (liquid and gas densities, liquid and gas viscosities), sand particle properties (density, size, concentration, angle of repose, sphericity), well geometry (pipe diameter, roughness and inclination angle), and fluid flow (flow pattern, superficial liquid and gas velocities, liquid holdup, water cut). The effect of each parameter on the critical particle transport velocity is analyzed to find the most important ones. The evaluations are validated by comparing with the previous work and experiments.
A field case example is analyzed as an application of the models with real field sand particle parameters. Good results are obtained for a large range of sand particle sizes. An angle of repose parameter calculation is demonstrated.