HIGH COLLAPSE CASING FOR DEEP WELL SERVICE
Sumitomo High Collapse Casing SM-T grade is
a seamless product designed for deep wells where
high collapse pressures are anticipated. In
order to meet deep well service requirements,
SM-T casing has improved collapse properties
well in excess of API ratings. These properties
are achieved by strict mill control incorporating
a unique production technique inclusive of quenching
and tempering. SM-T casing shows a very high
resistance to tension load, internal pressure,
and collapse. SM-95TS is also highly resistant
to sulfide stress corrosion cracking and can
be used for deep and sour gas and oil service.
Grade |
Yield
Strength |
Tensile
Strength min psi (MPa) |
Elongation
min % |
Collapse
Resistance |
min
psi (MPa) |
max
psi (MPa) |
SM-
80T |
80,000 (552) |
110,000 (758) |
100,000 (689) |
API Formula |
Refer
to Performance Table |
SM-
95T* |
95,000 (655) |
125,000 (862) |
110,000 (758) |
API Formula |
SM-
95TT* |
95,000 (655) |
125,000 (862) |
110,000 (758) |
API Formula |
SM-110T* |
110,000 (758) |
140,000 (965) |
125,000 (862) |
API Formula |
SM-110TT* |
110,000 (758) |
140,000 (965) |
125,000 (862) |
API Formula |
SM-125TT |
125,000 (862) |
155,000 (1069) |
135,000 (931) |
API Formula |
|
| *
|
Higher collapse
casing than SM-95T & SM-110T are available
on request. |
As wells are drilled deeper, the external pressures
applied to well casings become greater. Thus,
a well casing must have adequate collapse strength
to withstand these horizontal pressures without
deformation. For reasons of economy such casings
should also be as light-weight as possible while
still retaining ample collapse resistance properties.
With this in mind Sumitomo Metals has developed
its SM-T High Collapse Casing. This casing was
developed from experiments in which Sumitomo
studied the critical collapse pressure of a
well casing under external pressure in relation
to its longitudinal tensile strength and the
geometry of its cross section.
 |
Characteristics
1. Unique Production Technique
The material for SM-T casing is carefully
selected to insure structural homogeneity.
Strict control of heat treatment and dimensional
tolerances is adhered to throughout the
manufacturing process.
2. Rigid Dimensional Control
Dimensional tolerances, such as roundness,
straightness, O.D. and wall thickness
are strictly controlled.
3. Specified Collapse Value
A collapse test is carried out on each
production run of SM-T casing with the
same frequency as the tensile test using
the most modern testing equipment. |
|
