Ultra High-Strength Casing

Ultra High-Strength Casing

Ultra high-strength casing is often used as oil casing widely applicable in deep and ultra deep wells and HP-HT wells (high pressure and high temperature wells). The super high-strength pipe is also used for well exploration in other complex geological conditions. It has high strength, super toughness, good wear resistance and corrosion resistance, and strong anti-collapse, anti-dislocation deformation, anti-perforation deformation abilities. In order to explore petroleum and gas in the deep and ultra deep wells, JST ultra high-strength casing or super high-strength pipe is quite necessary (160ksi), because they have good impact toughness and they will not be in brittle fracture when using.

  • 1. Based on conventional CrMoV quenched and tempered steel, alloy design of JST ultra high-strength casing or super high-strength pipe adopts proper steel grades like low C, low Si, high-Cr, mid-Mo and micro-V. Under the premise of ensuring hardenability of steel, this design minimizes the carbon content so as to avoid damaging the steel toughness.  
    2. The joint and pipe body has same strength to ensure the resistance to internal pressure, external squeeze and the overall link performance of ultra high-strength casing.
    3. To meet the casing load requirements for operations in ultra deep wells, the yield strength of super high-strength pipe (Rt) should be equal or over 1000 Mpa, even reaching 1034 to 1172 Mpa. The tensile strength (RRm) should be equal or over 1120 Mpa. According to ultra-deep operating environment, there are corresponding collapse resistance requirements for casing.
    4. Our ultra high-strength casings are manufactured according to API grades, allowing us to offer the best solutions for each customer’s particular well conditions.
    5. All of super high-strength pipes are manufactured to the most exacting quality standards. We hold a global ISO 9001 registration for our operations, which follow a uniform quality policy and apply a rigorous quality management system.
    6. We can supply ultra high-strength casings in bare, uncoated condition or with OD/ID coatings such as bitumastic and coal tar epoxy coatings.
    7. Through the JST global network of manufacturing facilities and threading shops, we are able to ensure flexible delivery for our super high-strength pipes.
    8. We develop reasonable and feasible quenching and tempering temperature and time, and quenching medium, making more than 95% of the austenite transform into martensite and forming small and uniform tempering sorbite structure.
    9. We can supply ultra high-strength casings in bare, uncoated condition or with OD/ID coatings such as bitumastic and coal tar epoxy coatings.

    10. JST super high-strength pipe adopts the most advanced imported high-precision CNC dedicated screw thread machine tool to process threads. This ensures the processing precision of screw threads. Combined with unique threaded surface treatment technology, it greatly improves anti-adhesion and other properties of casing joint.
Chemical Composition of Ultra High-Strength Casing

The mechanical properties of super high-strength pipe are most sensitive to C, Si and Cr fluctuations. C significantly reduces the body ductility. Si easily reduces the low temperature toughness of steel and Cr is easy to form M23C6 carbide to reduced toughness. It is generally believed that S or P and other impurities will validate steel impact toughness. But its content is strictly controlled at a low level and the fluctuation range is very small, so its influence is not significant. Take JST Q125 steel for example, chemical composition control coefficient is as follows:
Chemical Composition Requirements of Q125-3 Ultra high-strength casing (%)

C Si Mn P S Mo V Ni
≤ 0.30 ≤ 0.40 ≤ 1.90 ≤ 0.02 ≤ 0.01 ≤ 0.40 ≤ 0.20 ≤ 0.99
Performance Control of Super High-Strength Pipe
Grade Yield Strength (Mpa) Tensile Strength (Mpa)
Q125 862-1034 ≥ 931
JST130 896-1103 ≥ 965
JST140 965-1172 ≥ 1034
JST150 1034-1241 ≥ 1103
JST155 1068-1275 ≥ 1137
JST160 1103-1310 ≥ 1172

Technical ParametersSpecifications details about JST ultra high-strength casing refer to the EXCEL table.

PaymentWe mainly accept L/C payment for super high-strength pipes

Founded in 1984, Jiangyin Changjiang Steel Tube Making Factory is a professional manufacturer of seamless steel tubes and various special pipes. Our products mainly cover tubing, line pipe, drill pipe, high strength casing, high pressure boiler pipe, marine pipe, cylinder tube, hydraulic prop tube, fluid pipe, structure pipe, etc. They have passed API 5CT, API 5L, API 5DP, CCS, LR, DNV, ABS, NK, BV, GL, PED, SGS, ISO9001:2000 and ISO14001:2004 certifications. Our ultra strength high-casings/super high-strength pipes have won widespread praise and recognition by customers.

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