In order to prevent possible sulfide stress
corrosion cracking in sour gas and oil wells
containing H2S, it is necessary to use specially
manufactured tubing and casing. API 5CT Group
2 grade tubing and casing have been developed
and used widely for this purpose. However these
may not be adequate in high concentration of
H2S.
To address this, Sumitomo Metal, after years
of research and development, has succeeded in
developing improved materials with higher strength
and higher corrosion resistance for casing and
tubing.
These are available in our SM-S series as shown
below.
Sumitomo Metals does not recommend SM sour
series greater than 110ksi grade for tubing
applications.
Each of these grades is produced with rigid
manufacturing controls covering chemical composition,
heat treatment (quenching and tempering), tensile
property, hardness and microstructure
|
Type |
Grade |
Mechanical
Characteristics |
Quality
Control |
| Yield
Strength |
Tensile
Strength |
HRC
Hardness |
Min.
tempering temp. |
SSC
test *
(1) |
| Min. |
Max. |
Min. |
Max. |
(oF) |
NACE
TM0177 Methode-A |
| API |
L80 |
80 |
95 |
95 |
23.0 |
1050 |
- |
| C90 |
90 |
105 |
100 |
25.4 |
1150 |
80%SMYS
(1atmH2S, Solution-A)
|
| T95 |
95 |
110 |
105 |
25.4 |
1200 |
80%SMYS
(1atmH2S, Solution-A)
|
| Sour
Service |
SM-80S |
80 |
95 |
95 |
23.0 |
1150 |
90%SMYS
(1atmH2S, Solution-A)
|
| SM-90S |
90 |
105 |
100 |
25.4 |
1150 |
90%SMYS
(1atmH2S, Solution-A)
|
| SM-95S |
95 |
110 |
105 |
26.0 |
1150 |
90%SMYS
(1atmH2S, Solution-A)
|
| SM-95TS
*(2)
|
95 |
110 |
105 |
26.0 |
1150 |
85%SMYS
(1atmH2S, Solution-A)
|
| High
Strength Sour Service |
SM-C100 |
100 |
115 |
105 |
27.0 |
1100 |
85%SMYS
(1atmH2S, Solution-A)
|
| SM-C110 |
110 |
125 |
115 |
30.0 |
1100 |
85%SMYS
(1atmH2S, Solution-A)
|
| High
Strength Mild Sour Service |
SM-110S |
110 |
125 |
115 |
30.0 |
1100 |
85%SMYS
(0.1atmH2S, Solution-B)
|
| SM-110TS
*(2) |
110 |
125 |
115 |
30.0 |
1100 |
85%SMYS
(0.1atmH2S, Solution-B)
|
| SM-125S |
125 |
140 |
130 |
36.0 |
1050 |
85%SMYS
(0.03atmH2S, Solution-B)
|
|
*(1)
SSC test of methode-B & methode-D is available
on request
*(2)
Collapse and sour
CHARACTERISTICS
1.Materials
The chemical compositions have been carefully
determined to provide resistance to sulfide
stress corrosion cracking as well as to insure
complete through wall hardening.
2. Heat Treatment
Quenching and tempering are conducted under
rigid temperature control to assure homogeneous
physical properties and micro structures.
New Higher Strength Sour Resistant Grades SM-110S,
SM-C100, SM-C110, SM-125S have been developed.
3. Micro Structure
These grades exhibit fully tempered martensite
which is considered to be the most desirable
for resistance to sulfide stress corrosion cracking.
4. Tensile Properties and Hardness
Yield strength is limited within a narrow range
and hardness is controlled to within the predetermined
maximum limit.
5. Sulfide Stress Cracking (SSC) Performance
SM sour resistant grades are designed for 85%
or 90% SMYS in NACE condition or equivalent
method such as Sc value (ex.Sc value).
Excellent SSC resistance has been achieved through rigorous, chemical composition,
heat treatment, microstructure, tensile properties, hardness and so on.
View
Graphs on the Next Page
|
