Progressive dewatering and inhibitor dispersal rolling pig
View Patent ↗A method for progressively dewatering a pipe or pipeline includes the use of a loose-fitting spherical- or quasi-spherical shaped pig body which rolls forward through the interior space of the pipe and temporarily captures and redistributes a portion of the volume of liquids available for capture and redistribution as the pig body rolls on past. Preferably, the portion captured is less than the volume available for capture. A part of the captured liquid may be redistributed to an upper quadrant of the pipe. Capture and redistribution are accomplished by way of a first bypass pathway and a second bypass pathway. One of the pathways may be a through-body pathway. The pig body may be a hollow pig body with a plurality of spaced-apart ports, a solid pig body with a plurality of paddle-like structures, or a cube-sphere type pig body with recessed external wall surfaces.
1. A method for progressively dewatering a pipe or pipeline, the method comprising the steps:
launching a pig body into an interior space of a pipe having a gas product flow under pressure, the pig body being selected from the group consisting of a spherical-shaped pig body and a quasi-spherical shaped pig body, the pig body being capable of rolling forward through the interior space of the pipe;
rolling the pig body forward within the gas product flow and through the interior space of the pipe;
capturing temporarily on a surface of the pig body a liquid portion of a volume of liquids residing within an area of the interior space of the pipe as the pig body rolls forward; and
redistributing the captured liquid portion within the interior space of the pipe as the pig body continues to roll forward and past the volume of liquids;
wherein the pig body includes at least a first bypass pathway and a second bypass pathway.
2. A method according to claim 1 wherein the first and second bypass pathways allow gas flow to bypass the pig body at a velocity greater than a velocity of the pig body as the pig body rolls forward.
3. A method according to claim 1 wherein the amount of bypass provided by the first bypass pathway is different than the amount of bypass provided by the second bypass pathway.
4. A method according to claim 1 wherein said redistributing step redistributes at least part of the captured liquid portion to an upper quadrant of the interior space of the pipe.
5. A method according to claim 1 wherein the captured liquid portion is less than the volume of liquids available for capture within the area.
6. A method according to claim 1 wherein at least a portion of said rolling step includes rolling along a non-linear path.
7. A method according to claim 1 wherein the first bypass pathway is a through-body pathway and the second bypass pathway is an external bypass pathway.
8. A method according to claim 1 wherein the first bypass pathway is a through-body pathway coaxial to a central axis of the pig body.
9. A method according to claim 1 wherein the first bypass pathway and second bypass pathways are external bypass pathways.
10. A method according to claim 1 wherein the pig body is a hollow body and the first bypass pathway is a through-body pathway provided by a plurality of spaced apart ports arranged about the pig body.
11. A method according to claim 10 wherein the pig body includes a reinforcing layer disposed between an internal and an external wall surface of the hollow body.
12. A method according to claim 10 wherein an internal wall surface of the pig body includes a plurality of ribbed surfaces.
13. A method according to claim 1 wherein at least one of the first and second bypass pathways is formed in part by at least one radially extending paddle-like structure.
14. A method according to claim 1 wherein at least one of the first and second bypass pathways is formed in part by at least two arcuate-shaped surfaces that share a common edge and are arranged substantially orthogonal one another.
15. A method according to claim 14 wherein at least one of two arcuate-shaped surfaces includes a lip located along a circumferential edge of the surface.
16. A method according to claim 14 wherein the first bypass pathway is a port passing through at least one of the two arcuate-shaped surfaces.
17. A method according to claim 1 wherein at least one of the first and second bypass pathways is formed in part by at least two arcuate-shaped oblique-angled surfaces that share a common edge.
18. A method according to claim 17 wherein at least one of the at least two arcuate-shaped oblique-angled surfaces includes a lip located along a circumferential edge of the surface.
19. A method according to claim 1 wherein at least one of the first and second bypass pathways is formed in part by a recessed portion of an external wall surface.
20. A method according to claim 19 wherein the recessed surface is a generally polygonal-shaped recessed surface.
21. A method according to claim 1 wherein at least one of the first and second bypass pathways is formed in part by a textured external wall surface.