Experimental studies of the effectiveness of cleaning the internal cavity of pipelines with hyperelastic pigs

Abstract

Problematic issues that arise during the cleaning of gas gathering systems of gas fields with cleaning pigs are considered. The requirements that must be met by the pig`s material intended for cleaning the inner cavity of well plumes from liquid pollution are given. The expediency of making pigs for cleaning complex pipeline systems from hyperelastic materials is substantiated. Cylindrical cleaning pistons made of hyperelastic materials with different physical and mechanical characteristics (polyurethane foam of different densities, urethane-coated polyurethane foam, self-destructive elastic-polymer composition, silicone sealant, silicone compound) were manufactured. Laboratory experimental installations made of glass pipes and branches were developed and installed to evaluate the efficiency of cleaning horizontal and low-lying sections of pipelines with pistons made of hyperelastic materials and to study the pig movement dynamics. A technical solution to change the forward direction of the pig movement to the reverse direction after the pig passes through the entire experimental pipeline is proposed. The pig movement dynamics of hyperelastic materials in pipelines was experimentally investigated, and the factors that affect the cleaning efficiency were determined. It is established at what speed of pig movement the cleaning efficiency of horizontal straight sections of the pipeline is maximized. The forces acting on the pig at the beginning of its movement through the pipeline, movement at a constant speed, and temporary stopping at the point of jamming are described. The main factors affecting the friction force between the pig and the inner wall of the pipeline are considered. The possible places and reasons for the temporary stoppage of pigs made of hyperelastic materials in pipelines and the negative consequences that this can lead to are established. Experimentally, it was found that through all investigated pigs made of hyperelastic materials, air flow occurs, which is fed into the pig space. Such overflow contributed to the improvement of the pipeline cleaning quality. Recommendations are provided for the application scope of various hyperelastic pigs