... pigs, i.e., cup, disc, and foam pigs. The experiments showed that a typical wax removal process using a pig followed four distinct phases, namely, wax breaking, plug formation, accumulation, and production phases. Wax accumulation can be very significant and is expected to be the dominating factor...

.... The coefficients in the equation were then obtained from a set of tests for a simple pipe-in-pipe bundle with half-shell pieces of foam fitted around the inner pipe. Dramatic heat losses as experienced in some of field applications were recorded when the porous insulation foam is under high nitrogen pressure. All...