Systems and method for sealing pipelines using a gel pig
The present invention provides systems and methods for curing a leakage in a pipeline, the system including at least one gel pig and at least one sealant composition; wherein the at least one gel pig and the at least one sealant composition form a pig train, adapted to move along the pipeline to a region of the leakage and to seal the leakage.
1. A system for curing at one leakage site in a pipeline, the system comprising:
a) at least one non-abrasive, fully flushable gel pig comprising:
i. a hygroscopic component in a concentration of 1-10% w/w;
ii. a surfactant in a concentration of 0 to 8%;
iii. water in a concentration of 70-95% w/w, and;
iv. a base in a concentration of 0-20%;
b) at least one sealant composition comprising:
vi. at least one filler;
vii. at least one gelling agent; and
viii. at least one aqueous agent;
wherein said at least one gel pig and said at least one sealant composition form a pig train, adapted to move along said pipeline to a region of said at least one leakage and to seal said at least one leakage.
2. A system according to claim 1 , wherein said at least one gel pig comprises one gel pig and said at least one sealant composition comprises one sealant composition.
3. A system according to claim 2 , wherein said at least one gel pig comprises one rear pig.
4. A system according to claim 1 , wherein said at least one gel pig comprises two gel pigs and said at least one sealant composition comprises one sealant composition.
5. A system according to claim 4 , wherein at least one of said two pigs has an average diameter of at least 5% less than an internal diameter of said pipeline.
6. A system according to claim 4 , wherein at least one of said two pigs has an average diameter of at least 10% less than an internal diameter of said pipeline.
7. A system according to claim 1 , wherein said at least one gel pig comprises three gel pigs and said at least one sealant composition comprises two sealant compositions.
8. A system according to claim 1 , wherein said pig train is adapted to move along said pipeline at a speed of 0.01 to 10 m/s.
9. A system according to claim 1 , wherein said base is in a concentration of 0.1-20% w/w and said at least one filler is in a concentration of 0.1-2% w/w.
10. A system according to claim 1 , wherein said surfactant is in a concentration of 0.1 to 2% and comprises an oil.
11. A system according to claim 1 , wherein said at least one gel pig comprises a rear pig and a front pig of different compositions.
12. A system according to claim 1 , wherein said pig train is adapted to conform to an inner profile of said pipeline.
13. A system according to claim 1 , wherein said system further comprises a pressurized fluid for propelling said system from a first end thereof along said pipeline.
14. A system according to claim 13 , wherein said pressurized fluid comprises a liquid.
15. A system according to claim 13 , wherein said pressurized fluid comprises a gas.
16. A system according to claim 13 , wherein said pressurized fluid comprises a tri-phase fluid.
17. A system according to claim 13 , wherein said pressurized fluid is at a pressure of 1-150 bar.
18. A system according to claim 13 , wherein said system further comprises a counter pressurized fluid for counter-pressurizing said pig train from a second end thereof.
19. A system according to claim 1 , wherein said pig train is adapted to prevent a bypass of a propelling product of more than 30%.
20. A system according to claim 1 , wherein said pig train is adapted to be extracted from said pipeline via a conduit of less than two inch diameter at a pressure of less than 3 bar.