Abstract:
Flexible, mechanically strong composite hydrogel materials based on polyacrylamide hydrogel (PAAH), clay
minerals (kaolin, bentonite and montmorillonite), poly-N-vinylpyrrolidone (PVP) and SiO2 were developed
for cleaning the inner surface of pipelines. The mechanical strength of composite hydrogels increases in the
following order: PAAH-PVP > PAAH-Montmorillonite > PAAH-SiO2 > PAAH-Bentonite. The results
showed that the composite hydrogel samples are able to sustain more than 200 cycles of vertical deformation
without damage. The hydrogel «pigs» selected according to the values of tensile strength and Young's modulus
were tested on model «small» and «big» pipelines. The application of hydrogel «pigs» for cleaning the
model pipelines proved to be successful. In contrast to mechanical analogues, hydrogel «pigs» pass freely
through the pipelines of various shape and size, ensure necessary hydraulic pressure in the inner surface, provide
explosion and fire safety, and absorb water along in the course of movement inside the pipeline. Their
cleaning efficiency of the model pipelines from the asphaltene-resin-paraffin deposits (ARPD) was evaluated
as 93–95 %. The scaled up hydrogel «pigs» were fabricated for cleaning of oilfield pipes. The proposed materials
would be of interest for oil transportation companies due to cost-efficiency and technological feasibility.
