Packer elements with low thermal expansion
Methods and apparatus for performing a sealing operation. A sealing element is introduced into a wellbore having a temperature. The sealing element comprises a material having a positive coefficient of thermal expansion (CTE), and a material having a negative CTE. The sealing element is expanded to contact an adjacent surface. The material having a negative CTE expands when the wellbore temperature is decreasing and the expansion of the negative CTE material maintains contact of the sealing element with the adjacent surface while the wellbore temperature is decreasing.
1. A method for performing a sealing operation, the method comprising:
introducing a sealing element into a wellbore having a temperature; wherein the sealing element comprises:
a material having a positive coefficient of thermal expansion (CTE), wherein the positive CTE material is: a thermoplastic, polyetheretherketone, a hydrogenated acrylonitrile butadiene rubber, a fluorocarbon-based fluoroelastomer, a tetrafluoroethylene and propylene copolymer, a perfluoroelastomer, or any combination thereof; and
a material having a negative CTE, wherein the negative CTE material is: a metal tungstate; a MnCoGe compound alloyed with at least one of In, Ni, Cr, Ga, or Sb; alloys of (Bi,La) NiO 3 ; metal phosphates; metal molybdates; metal vanadates; ScF 3 ; CuO nanoparticles; PbTiO 3 ; CoO 3 ; BiNiFeO 3 ; MnSnZnN; Zr(WO 4 ) 2 ; or any combination thereof;
wherein the negative CTE material is compounded with the positive CTE material;
expanding the sealing element to contact an adjacent surface by applying an external force to the sealing element; and
wherein the material having a negative CTE expands when the wellbore temperature is decreasing; wherein the expansion of the negative CTE material maintains contact of the sealing element with the adjacent surface while the wellbore temperature is decreasing.
2. The method of claim 1 , wherein the sealing element is a component of a swell packer and the expanding the sealing element to contact an adjacent surface comprises contacting the sealing element with a fluid or allowing the sealing element to contact the fluid.
3. The method of claim 1 , wherein the sealing element is a component of a compression set element and the expanding the sealing element to contact an adjacent surface comprises compressing the sealing element.
4. The method of claim 1 , wherein the sealing element is a component of a liner hanger and the expanding the sealing element to contact an adjacent surface comprises stretching the sealing element.
5. The method of claim 1 , wherein the sealing element is disposed on a wellbore packer, a wellbore tubing, a wellbore conduit, a wellbore tool, or a mandrel.
6. The method of claim 1 , wherein the negative CTE material has a particle size between about 0.01 micron to about 100 microns.
7. The method of claim 1 , wherein the negative CTE material is surface treated prior to compounding with the positive CTE material.
8. The method of claim 7 , wherein the surface treatment is the application of a zirconium conversion layer.
9. The method of claim 1 , wherein the sealing element is formed by compression molding or injection molding.
10. The method of claim 1 , wherein the sealing element is a molded seal, crimp seal, or a V-packing seal system.
11. The method of claim 1 , wherein the wellbore temperature decreases after the expansion of the sealing element.
12. The method of claim 1 , wherein the positive CTE material is an elastomer.
13. The method of claim 1 , wherein the negative CTE material is compounded with the positive CTE material by adding the negative CTE material to the positive CTE material at a rate of 5 parts per hundred to 50 parts per hundred.
14. The method of claim 1 , wherein the negative CTE material has a distribution of particle sizes such that greater than 50% of the negative CTE particles have a 10× distribution in mean particle sizes.
15. The method of claim 1 , wherein at least some of the negative CTE material comprises nanoparticles.
16. The method of claim 1 , wherein the negative CTE material is pretreated with a siloxane surface pretreatment prior to compounding with the positive CTE material.
17. The method of claim 1 , wherein the negative CTE material does not comprise a titanium alloy.
18. The method of claim 1 , wherein the sealing element is coated with an elastomer.