SS Downhole Pump

Project in Schlumberger


Stainless steels are high-alloy steels that have excellent corrosion resistance in comparison with other steels as they contain more chromium.

Based on their crystalline structure, stainless steels are divided into three groups, namely, martensitic, austenitic and ferritic steels.

A combination of martensitic and ferritic steels forms a fourth group known as precipitation-hardened steels.

Datasheet stainless steel UNS S50100

Chemical Composition (Weight %) Mechanical Properties
C (%) ≥ 0.10 Density(g/cm³) 7.75
Si(%) ≤ 1.00 Elastic modulus(Gpa) 190-210
Mn(%) ≤ 1.00 Yield Rp0.2 (MPa) 390
P(%) ≤ 0.040 Elongation A (%) 18
S (%) ≤ 0.030 Poisson’s ratio 0.27-0.30
Cr (%): 4.00 ~ 6.00 Thermal expansion (@ 0-100°C/32-212°F) 11.2 µm/m°C
Mo(%): 0.40 ~ 0.65 Thermal conductivity (@ 100°C/212°F) 36.7 x W/m.K

The produced water in oil wells contains a variety of corrosive substances, such as Saline water, Cl-1, SO4-2, HCO3-1, CO3-2, H2S, CO2, Oxygen, which can cause strong corrosion to the carbon steel pump.

corrosion of sucker rod pump

Although stainless steel (S50100, S30400) is extremely resistant to corrosion, it is relatively soft and has very low hardness and strength. Conventional processing methods, such as honing, cannot meet the requirements of the dimensional accuracy of the pump barrel.

In order to solve this problem, we adopt precision rolling process to ensure the precision of stainless steel pump barrel. The stainless steel pump barrel is chrome plated to improve the wear resistance.

standard sucker rod pump painting and marking

Below are the main technical parameters of the stainless steel insert pump:

Type Thick wall rod pump Thin wall rod pump Tubing pump
Bore size (in) 1 1/16~2 1/4 1 1/4~2 1/2 1 3/4~3 3/4
Plunger length (ft) 2-24
Barrel length (ft) 2-34
Material Barrel A3: Chrome plate on 4/6 chrome steel

A6: Chrome plate on austenitic stainless steel

B3: Heavy chrome plate on 4/6 chrome steel

B6: Heavy chrome plate on austenitic stainless steel

Plunger D1-D3: Spray metal with Ni/Cu alloy ends

E1-E3: Spray metal with Nickel plated pin ends and entire length of inside diameter

F1-F3: Spray metal with Nickel plated pin ends and entire length of inside diameter

Corrosion medium H2S, CO2, Saline water, Oxygen