# US 12,000,237 B2 · Well sealing material and method of producing a plug

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- Number: US 12,000,237 B2
- Document ID: US12000237B2
- Status: Granted
- Kind: B2
- Application number: 17/254,091
- Filed: 2019-06-21
- Published: 2021-08-26
- Granted: 2024-06-04
- Earliest claimed: 2018-06-25
- Assignees: Rawwater Engineering Limited
- Applicants: Rawwater Engineering Limited
- Inventors: Robert Eden; Joseph Oluleke
- Web page: https://patentgrep.com/patent/US12000237B2

## CPC

- E21B 33/134: Bridging plugs
- C22C 12/00: Alloys based on antimony or bismuth
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- C22C: ALLOYS (treatment of alloys C21D, C22F)

## Abstract

Bismuth-based alloys comprising at least about 50% by weight bismuth, about 30 to about 35% by weight tin, and about 1.8 to about 2.8% by weight antimony; and an alloy of bismuth and silver comprising about 90 to about 97% by weight bismuth and about 3 to about 9% by weight silver. A plug comprising an alloy of bismuth, tin, and antimony; and a plug comprising an alloy of bismuth and silver. A method of using a plug made from a bismuth-based alloy to seal a well, wherein a length of a well is filled with the molten alloy and the molten alloy is allowed to solidify.

## Claims

### Claim 1

A method of forming a plug in a well comprising:
providing an alloy composition of bismuth, tin, and antimony consisting essentially of 31 to 33% by weight of the tin, 2.1 to 2.4% by weight of the antimony, and a balance of the bismuth;
filling a length of the well with the alloy composition in a molten state; and then
allowing the alloy composition in the molten state to solidify;
wherein the alloy composition does not creep at a temperature range from 60° C. to 100° C.

### Claim 2 (depends on 1)

The method according to claim 1 wherein the bismuth is present at 65% by weight in the alloy composition.

### Claim 3 (depends on 1)

The method according to claim 1 wherein the tin is present at 32% by weight in the alloy composition.

### Claim 4 (depends on 1)

The method according to claim 1 wherein the antimony is present at 2.28% by weight in the alloy composition.

### Claim 5 (depends on 1)

The method according to claim 1 further comprising sealing the well with the plug.

### Claim 6 (depends on 1)

The method according to claim 1 wherein the well is an oil well.