Effect of Particle Size and Surface Properties on the Sandbed Erosion with Water Flow in a Horizontal Pipe

Abstract

Summary An experimental study was conducted to investigate the transport of sand particles over the sand bed deposited in a horizontal conduit by using turbulent flow of water. The main objectives were to determine the near-wall turbulence characteristics at the onset of bed erosion (i.e., near-wall velocity profile, Reynolds shear stresses, and axial-turbulent intensity); to determine critical velocity required for particle removal from the bed deposits; and more specifically, to determine how the sand-particle size and surface characteristics would influence the critical velocity required for the onset of bed erosion and the near-wall turbulence characteristics. A large-scale horizontal flow loop equipped with a nonintrusive laser-based particle-image velocimetry (PIV) system has been used for the experiments. The effect of sand-particle surface characteristics (i.e., wettability) on the critical velocity and the near-wall turbulence characteristics were investigated by using treated and untreated industrial sands of four different mesh sizes (i.e., 20/40, 30/50, 40/70, 100). The PIV technique was used to determine instantaneous local velocity distribution near the stationary sandbed fluid interface under subcritical and critical flow conditions. The near-wall velocity distribution measured directly at the sand bed/fluid interface together with the measured frictional pressure-loss values were then used for the evaluation of the Reynolds shear stresses and axial turbulent intensities acting at the bed/fluid interface. The results indicated that critical velocity for the onset of particle removal from sand beds increased with the increasing particle size. When sands with special surface treatment were used, it was observed that the critical velocity required for the onset of the bed erosion was significantly lower than that of required for the untreated sands. The degree of reduction in critical velocity varied between 14 and 40% depending on the particle size. In this study, by conducting experiments under controlled conditions, we provided much-needed fundamental data that can be used for the development of improved solid-transport design criteria and suitable mitigation technologies. In particular, we have shown the proof of concept that the surface-treated sand particles might have great potential for improving the transport efficiency of proppants used for hydraulic-fracturing operations.

Review and Perspectives of Coated Proppant Technology

“…Longer fracture lengths can be achieved by using self-suspending proppant and reducing the amount of proppant and fracturing fluid . The settling velocity of the proppant is mainly affected by the wettability and diameter of the proppant and the viscosity and velocity of the transport fluid . At present, there are two main methods for preparing a self-suspending proppant: (1) coating the surface of the proppant with hydrophobic materials ,− and (2) attaching swelling materials to the surface of the proppant to increase the volume of the proppant. , The preparation process of self-suspending proppant is fast, which can reduce the cost of preparation and transportation.…”

“…93 The settling velocity of the proppant is mainly affected by the wettability and diameter of the proppant and the viscosity and velocity of the transport fluid. 94 At present, there are two main methods for preparing a self-suspending proppant: (1) coating the surface of the proppant with hydrophobic materials 37,95−97 and…”

“…The settling velocity of the proppant is related to the wettability of the proppant surface. When the fluid transporting the particles is water, the hydrophobic surface particles have better self-suspending ability and can be carried by the fluid for longer distances. , The hydrophobic nature of the proppant surface causes air bubbles to adhere to the proppant surface, increasing the buoyancy of the proppant. A superhydrophobic self-suspending proppant was prepared by coating epoxy resin on ceramic proppant, and its self-suspending ability was 16 times that of the conventional proppant.…”

Influence of slug flow on sand dune transport in a 3.6° upward inclined pipeline

“…They observed large fluctuations in near‐bed velocity indicating the impact of flow turbulence in bed erosion. Hirpa et al 23 applied the Bizhani and Kuru 22 flow visualization technique to determine the critical velocity necessary for particle removal from horizontal bed deposits inside a horizontal pipe. Archibong‐Eso et al 24 studied the hydraulic transport of sand particles in pipelines in both horizontal and 30° upward inclined orientations.…”

Wear Behaviors of AISI 4145H Drilling Tool Steel under Drilling Fluid Environment Conditions

“…During real drilling operations, the solid particles in the mud mainly include talc, dolomite, fluorite and quartz [ 11 , 12 , 13 ]. The hardness of the first three particles is lower ( H A < 210), while that of quartz is greater than 1000.…”