Different Types of Sucker Rod
API Grade Sucker Rods
Standard API sucker rods are available in several steel grades each with its own set of properties and field of application:
Grade C: For light to medium load applications in wells that are sufficiently protected against corrosion.
Minimum yield: 414 MPa (60,000 psi)
Tensile range: 621-793 MPa (90,000-115,000 psi)
Grade K: For light to medium load applications in corrosive environments. However, to prolong service life, we recommend to sufficiently protect against corrosion.
Minimum yield: 414 MPa (60,000 psi)
Tensile range: 621-793 MPa (90,000-115,000 psi)
Grade D: For medium to heavy load applications in wells that are sufficiently protected against corrosion.
Minimum yield: 586 MPa (115,000 psi)
Tensile range: 793-965 MPa (115,000-140,000 psi)
Grade D special: Combines the properties of grade K and grade D carbon sucker rods. For medium to heavy load applications in corrosive environments. However, to prolong service life, we recommend to sufficiently protect against corrosion.
Minimum yield: 586 MPa (115,000 psi)
Tensile range: 793-965 MPa (115,000-140,000 psi)
Corrosion Resistant Sucker Rods
In corrosive wells, the service life of the API grade sucker rods is significantly reduced, resulting in high service fees and non-productive time (NPD).
To limit the negative effects of corrosion, we introduced a special surface finish that effectively shields sucker rod against any corrosive fluids or gases.
Each rod is tungsten alloy electroplated over its full length, giving it a strong and stable coating with a surface hardness of 57 HRC-60 HRC.
The protective layer effectively protects the sucker rod against abrasion and corrosion. Hydrogen embrittlement that weakens the rod string is no problem anymore.
High Strength Sucker Rods
In very deep wells or when running large capacity pumps, the increased load often is too high for standard API grade sucker rods.
Sovonex™ high strength sucker rods are specially developed to overcome this problem. Made from high-grade steel with a maximum tensile strength of 1,195 MPa(173,339 psi) and a minimum yield of 795 MPa (115,000 psi), these premium rods are well suited for extra heavy load applications.
The following premium sucker rods are available:
High Strength (HS): For heavy to extra heavy load applications.
High Strength Hardened (HSH): Like HS grade, but with a minimum surface hardness of 42 HRC and a core hardness of at least 224 HB.
Polished Rods
A polished sucker rod runs inside the stuffing box and provides a connection between the surface pumping unit and the downhole sucker rod string.
Furnished with a wear resistant and anti-corrosive coating, Sovonex™ polished rods reach 65 on the Rockwell "C" hardness scale (65 HRC). This special surface finish enhances the pressure seal of the stuffing box and extends the service life of the rod.
