Alternative method to cementing casing and liners
A method of sealing casing or liners in a wellbore is described. The stands of casing or liner receive a jacket bonded to the outer surface. Preferably, the jacket is a rubber compound bonded to the outer wall. The formulation responds to well fluids to swell at a predetermined rate. The casing or liner can also be expanded with a swage preferably prior to the onset of significant jacket swelling. Packers and sealing hangers can be optionally added at the extremes of the casing or liner string to further secure against channeling between adjacent formations.
1. A method of sealing a tubular string in a wellbore, comprising:
providing a seamless covering on a plurality of stands that make up the tubular string;
running the tubular string to a desired position in the wellbore;
using well fluids to promote swelling of said covering at a rate slow enough to allow placement of said string at the depth desired; and
sealing the wellbore from said swelling.
2. The method of claim 1 , comprising:
bonding the covering to the stands.
3. The method of claim 1 , comprising:
expanding the stands.
4. The method of claim 3 , comprising:
performing said expanding before said covering swells completely.
5. The method of claim 1 , comprising:
providing extrusion barriers for said covering near at least one extremity of said string; and
leaving the ends of said stands uncovered.
6. The method of claim 5 , comprising:
providing a combination hanger and extrusion barrier for said covering near an upper end of said string.
7. The method of claim 1 , comprising:
overlapping said string with existing well casing;
expanding an end of said string to support it from said existing well casing.
8. The method of claim 7 , comprising:
providing substantially circumferential sealing contact between said string and said existing well casing due to said expansion;
using said sealing contact as an extrusion barrier.
9. The method of claim 1 , comprising:
making said covering from a material that swells in the presence of one of oil based mud and oil based hydrocarbon production.
10. The method of claim 1 , comprising:
making said covering from a material that swells in the presence of one of water based systems and water based production well fluids.
11. The method of claim 1 , comprising:
allowing said covering to fill wellbore irregularities due to said swelling.
12. The method of claim 1 , comprising:
making said covering from a polymer.
13. The method of claim 12 , comprising:
making said covering from rubber.
14. The method of claim 2 , comprising:
expanding the stands.
15. The method of claim 14 , comprising:
performing said expanding before said covering swells completely.
16. The method of claim 15 , comprising:
allowing said covering to fill wellbore irregularities due to said swelling.
17. The method of claim 16 , comprising:
making said covering from a polymer.
18. The method of claim 17 , comprising:
providing extrusion barriers for said covering near at least one extremity of said string.
19. The method of claim 18 , comprising:
providing substantially circumferential sealing contact between said string and said existing well casing due to said expansion;
using said sealing contact as an extrusion barrier.
20. The method of claim 19 , comprising:
making said covering from rubber.