Project Description

Drilling Collars for Water Wells

Description:

  1. Drilling collars for water wells are primarily used in water well drilling operations to increase the weight of the drill string, applying pressure to the drill bit.
  2. Drilling collars can be customized to different specifications according to the model of the drilling rig, following standards such as API Spec 7-1 or SY/T5144-2013, and manufactured according to drawings.
  3. Materials include: 4145H, 4145HM, 4137, DZ50, etc.

Specifications Chart

Table of Drilling Collar Dimensions and Specifications

Thread Type Outer Diameter (mm) Outer Diameter (inch) Inner Diameter (mm) Inner Diameter (inch) Length (mm) Length (ft) Shoulder Fillet Diameter (mm) Shoulder Fillet Diameter (inch) Ref. Bending Strength Ratio
NC23-31 79.4 3-1/8 31.8 1-1/4 9150 30ft 76.2 2.57 2.57:1
NC26-35(2-3/8IF) 88.9 3-1/2 38.1 1-1/2 82.9 2.42 2.42:1
NC31-41(2-7/8IF) 104.8 4-1/8 50.8 2 100.4 2.43 2.43:1
NC35-47 120.7 4-3/4 50.8 2 114.7 2.58 2.58:1
NC38-50(3-1/2IF) 127 5 57.2 2-1/4 121 2.38 2.38:1
NC44-60 152.4 6 57.2 2-1/4 9150 or 9450 30ft or 31ft 144.5 2.49 2.49:1
NC44-60 152.4 6 71.4 2-13/16 144.5 2.84 2.84:1
NC44-62 158.8 6-1/4 57.2 2-1/4 149.2 2.91 2.91:1
NC46-62(4IF) 158.8 6-1/4 71.4 2-13/16 150 2.63 2.63:1
NC46-65(4IF) 165.1 6-1/2 57.2 2-1/4 154.8 2.76 2.76:1
NC46-65(4IF) 165.1 6-1/2 71.4 2-13/16 154.8 3.05 3.05:1
NC46-67(4IF) 171.4 6-3/4 57.2 2-1/4 159.5 3.18 3.18:1
NC50-67(4-1/2IF) 171.4 6-3/4 71.4 2-13/16 159.5 2.37 2.37:1
NC50-70(4-1/2IF) 177.8 7 57.2 2-1/4 164.7 2.54 2.54:1
NC50-70(4-1/2IF) 177.8 7 71.4 2-13/16 164.7 2.37 2.37:1
NC50-72(4-1/2IF) 184.2 7-1/4 71.4 2-13/16 169.5 3.12 3.12:1
NC56-77 196.8 7-3/4 71.4 2-13/16 185.3 2.70 2.70:1
NC56-80 203.2 8 71.4 2-13/16 190.1 3.02 3.02:1
6-5/8REG 209.6 8-1/4 71.4 2-13/16 195.7 2.93 2.93:1
NC61-90 228.6 9 71.4 2-13/16 212.7 3.17 3.17:1
7-5/8REG 241.3 9-1/2 76.2 3 223.8 2.81 2.81:1
NC70-97 247.6 9-3/4 76.2 3 232.6 2.57 2.57:1
NC70-100 254 10 76.2 3 237.3 2.81 2.81:1
8-5/8REG 279.4 11 76.2 3 266.7 2.84 2.84:1

Note:

  1. Types of Threads: NC-number type, IF-inner plain type, REG-regular type.
  2. Bending Strength Ratio: The ratio of the bending section modulus of the inner thread critical section to that of the outer thread critical section.

In addition, our company can produce special drilling collars and high-efficiency wear-resistant extended drilling collars according to customer requirements besides the standard drilling collars and spiral drilling collars mentioned above.

Mechanical Properties Table

Mechanical Properties of Drilling Collars

Outer Diameter Range (mm) Yield Strength (MPa) Tensile Strength (MPa) Elongation (%) Brinell Hardness (HB) Charpy Impact Energy (Akv J)
79.4～171.4 (3-1/8～6-3/4) ≥758 ≥965 ≥13 285～341 ≥54
177.8～279.4 (7～11) ≥689 ≥930 ≥13 285～341 ≥54

Under special conditions, the Charpy impact energy can be agreed upon by both parties to be greater than 70J.