# US 4,400,211 A · Alloy for making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking

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- Number: US 4,400,211 A
- Document ID: US4400211A
- Status: Granted
- Kind: A
- Application number: 06/383,630
- Filed: 1982-06-01
- Granted: 1983-08-23
- Earliest claimed: 1981-06-10
- Assignees: Sumitomo Metal Industries, Ltd.
- Inventors: Takeo Kudo; Yasutaka Okada; Taishi Moroishi; Akio Ikeda; Hiroo Ohtani; Kunihiko Yoshikawa
- Web page: https://patentgrep.com/patent/US4400211A

## CPC

- C22C 38/44: with molybdenum or tungsten
- C22C 19/053: {with the maximum Cr content being at least 30% but less than 40%}
- E21B 17/00: Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; {Cables;} Casings; Tubings
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S-CO.sub.2 -Cl.sup.- environment, which comprises the following alloy composition: ______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110% 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% one or more of Nb, Ti, Ta, Zr and V in the total amount of 0.5-4.0%, if necessary Fe and incidental impurities: balance. ______________________________________

## Claims

### Claim 1

An alloy for use in making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking, the alloy composition consisting essentially of:
______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110%, 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% Fe and incidental impurities: balance. ______________________________________

### Claim 2 (depends on 1)

An alloy as defined in claim 1, in which the nickel content is from 40 to 60%.

### Claim 3 (depends on 1)

An alloy as defined in claim 1, in which the sulfur content is not more than 0.0007%.

### Claim 4 (depends on 1, 2, 3)

An alloy as defined in claim 1, 2 or 3, in which the phosphorous content is not more than 0.003%.

### Claim 5

An alloy for use in making high strength deep well casing and tubing having improved resistance to stress corrosion cracking, the alloy composition consisting essentially of:
______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110% 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% one or more of Nb, Ti, Ta, Zr and V in the total amount of 0.5-4.0% Fe and incidental impurities: balance. ______________________________________

### Claim 6 (depends on 5)

An alloy as defined in claim 5, in which the nickel content is from 40-60%.

### Claim 7 (depends on 5)

An alloy as defined in claim 5, in which the sulfur content is not more than 0.0007%.

### Claim 8 (depends on 5, 6, 7)

An alloy as defined in claim 5, 6 or 7, in which the phosphorous content is not more than 0.003%.

### Claim 9

An alloy for use in making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking, the alloy composition consisting essentially of:
______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0.05-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110%, 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% Fe and incidental impurities: balance. ______________________________________

### Claim 10 (depends on 9)

An alloy as defined in claim 9, in which the content of nickel is from 40 to 60%.

### Claim 11 (depends on 9)

An alloy as defined in claim 9, in which the sulfur content is not more than 0.0007%.

### Claim 12 (depends on 9, 10, 11)

An alloy as defined in claim 9, 10 or 11, in which the phosphorous is not more than 0.003%.

### Claim 13 (depends on 12)

An alloy as defined in claim 12, in which the N content is 0.10-0.25%.

### Claim 14

An alloy for use in making high strength deep cell casing and tubing having improved resistance to stress corrosion cracking, the alloy composition consisting essentially of:
______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0.05-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110% 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% one or more of Nb, Ti, Ta, Zr and V in the total amount of 0.5-4.0% Fe and incidental impurities: balance. ______________________________________

### Claim 15 (depends on 14)

An alloy as defined in claim 14, in which the nickel content is from 40 to 60%.

### Claim 16 (depends on 14)

An alloy as defined in claim 14, in which the sulfur content is not more than 0.0007%.

### Claim 17 (depends on 14, 15, 16)

An alloy as defined in claim 14, 15 or 16, in which the phosphorous content is not more than 0.003%.

### Claim 18 (depends on 17)

An alloy as defined in claim 17, in which the N content is 0.10-0.25%.

### Claim 19

An alloy for use in making high strength deep well casing and tubing having improved resistance to stress corrosion cracking, the alloy composition consisting essentially of:
______________________________________ C: .ltoreq.0.1% Si: .ltoreq.1.0% Mn: .ltoreq.2.0% P: .ltoreq.0.030% S: .ltoreq.0.005% N: 0.05-0.30% Ni: 30-60% Cr: 15-35% Mo: 0-12% W: 0-24% Cr(%) + 10Mo(%) + 5W(%) .gtoreq. 110% 7.5% .ltoreq. Mo(%) + 1/2W(%) .ltoreq. 12% Cu: 0-2.0% Co: 0-2.0% rare earths: 0-0.10% Y: 0-0.20% Mg: 0-0.10% Ca: 0-0.10% one or more of Nb and V in the total amount of 0.5-4.0% Fe and incidental impurities: balance. ______________________________________

### Claim 20 (depends on 19)

An alloy as defined in claim 19, in which the nickel content is from 40-60%.

### Claim 21 (depends on 19)

An alloy as defined in claim 19, in which the sulfur content is not more than 0.0007%.

### Claim 22 (depends on 19, 20, 21)

An alloy as defined in claim 19, 20 or 21, in which the phosphorous content is not more than 0.003%.