Study on scour stripping of oil-wax gels in pipes

Abstract

In this study, soft gel stripping experiments were conducted under different temperatures and flow velocity conditions by a flow loop. The flow area of pipes increased with an increase in flow velocity. However, partial or complete removal of soft gels occurred when flow velocity increased to a critical point. The hydrodynamic force from oil flow, adhesive contact force and yield stress of soft gels were calculated and compared. The hydrodynamic force increased with an increase in flow velocity. Under the dissolution and shear effect, the flow area showed a step-wise increase when hydrodynamic force did not meet the requirements of adhesion failure and structural failure. The soft gels were stripped completely when the force met the requirements. The lower strength of soft gels resulted in lower requirements of adhesion failure and structural failure. Thus, accumulation problems of soft gels can be solved by changing flow parameters.

Keywords

• Waxy crude
• Soft gels
• Shear stripping
• Structural failure
• Adhesion failure