A packer connected to a casing pipe, the packer including a connecting tube made of metal and connected to the casing pipe, and a packer part made of metal and attached around the connecting tube. The packer part has a hollow part inside. A sealed liquid that thermally expands is sealed in the hollow part. An outer peripheral wall of the packer part includes an expansive part that protrudingly deforms outward with the thermal expansion of the sealed liquid.
1. A packer connected to a casing pipe to seal a gap formed between a wall of a well and the casing pipe inserted into the well in drilling of the well, the packer comprising:
a connecting tube made of metal and connected to the casing pipe; and
a packer part made of metal and attached around an outer periphery of the connecting tube, the packer part expanding to abut against the wall of the well, press the wall, and seal the gap from the wall of the well,
wherein:
the packer part has a hollow part inside thereof,
a sealed liquid that thermally expands is sealed in the hollow part,
an outer peripheral wall of the packer part includes an expansive part that protrudingly deforms outward with the thermal expansion of the sealed liquid,
the outer peripheral wall of the packer part is made from a thin metal plate, and
the expansive part has a bellows shape formed by folding a part of the outer peripheral wall.
2. The packer according to claim 1 , wherein the sealed liquid comprises water.
3. The packer according to claim 2 , wherein the outer peripheral wall of the packer part includes a cleavage part that cleaves when a pressure of the sealed liquid becomes at least a predetermined pressure to release the sealed liquid to outside of the packer part.
4. The packer according to claim 3 , wherein the cleavage part comprises a thin-walled part.
5. The packer according to claim 1 , wherein the outer peripheral wall of the packer part includes a cleavage part that cleaves when a pressure of the sealed liquid becomes at least a predetermined pressure to release the sealed liquid to outside of the packer part.
6. The packer according to claim 5 , wherein the cleavage part comprises a thin-walled part.
7. A packer connected to a casing pipe, the packer comprising:
a connecting tube made of metal and connected to the casing pipe; and
a packer part made of metal and attached around the connecting tube,
wherein:
the packer part has a hollow part inside thereof,
a sealed liquid that thermally expands is sealed in the hollow part, and
an outer peripheral wall of the packer part includes (i) an expansive part that protrudingly deforms outward with the thermal expansion of the sealed liquid, and (ii) a rupture disk that ruptures when a pressure of the sealed liquid becomes at least a predetermined pressure to release the sealed liquid to outside of the packer part.
8. The packer according to claim 7 , wherein the outer peripheral wall of the packer part is made from a thin metal plate, and the expansive part has a bellows shape formed by folding a part of the outer peripheral wall.
9. The packer according to claim 8 , wherein the sealed liquid comprises water.
10. The packer according to claim 7 , wherein the sealed liquid comprises water.