Tension, torque, bending, compression, fatigue and combined operating loads.
DRILL STRING PRODUCTS
Drill Pipe
Drill pipe for torque transfer and drilling-fluid circulation, supplied with connection and inspection requirements under review.
StandardAPI 5DP · ISO 11961
Size / supply range2-3/8 in to 6-5/8 in typical outside-diameter range · Range 2 and Range 3 lengths
Grades / materialsE75 / X95 · G105 / S135
Connections / optionsAPI NC and FH connection families · Selected high-torque connections
ROTARY DRILL STRING
Torque, axial load and drilling fluid through one working string.
Drill pipe connects the surface drive system to the bottom-hole assembly. During drilling it is repeatedly rotated, tensioned, compressed and bent while circulating drilling fluid under pressure. The complete assembly combines a heat-treated pipe body, upset ends and rotary-shouldered tool joints.
OAK PIPE coordinates pipe-body grade, upset, tool-joint geometry, connection, hardbanding, internal coating, inspection and delivery against the drilling program.
Internal diameter, pressure loss, flow rate, erosion and tool-joint bore.
Connection handling, casing wear, hardbanding, corrosion and inspection practice.
SUPPLY OVERVIEW
Typical API drill pipe specifications.
This overview supports initial enquiry preparation. The requested API edition and complete drill-string design govern final dimensions, tolerances and performance.
| Primary standard | API Spec 5DP / ISO 11961; rotary-shouldered connections referenced to API Spec 7-2 where applicable |
|---|---|
| Typical pipe-body OD range | 2⅜ in to 6⅝ in (60.3–168.3 mm), subject to nominal mass, grade and configuration |
| Common grades | E75, X95, G105 and S135; service-specific requirements reviewed separately |
| Typical length ranges | Range 1: 18–22 ft; Range 2: 27–30 ft; Range 3: 38–45 ft |
| Upset configurations | IU (Internal Upset), EU (External Upset) and IEU (Internal-External Upset), according to size and design |
| Tool-joint material | Quenched-and-tempered alloy steel matched to the required connection and mechanical properties |
| Connection families | NC and selected IF, FH or REG configurations where technically applicable; exact geometry must be specified |
| Hardbanding | Casing-friendly or other specified hardbanding systems; placement and acceptance criteria agreed with the order |
| Internal protection | Bare bore or specified internal coating; application and inspection requirements to be confirmed |
| Marking & protection | Traceable pipe identification, connection compound / preservation as ordered and suitable thread protectors |
Tool-joint OD, ID, bevel diameter and make-up requirements are connection-specific and must be checked as one assembly.
PIPE-BODY GRADES
Common API 5DP strength levels.
Minimum yield strength is only one input. Fatigue demand, wall thickness, drilling loads, environment, tool-joint design and inspection program must be considered together.
| Grade | Specified minimum yield | Selection context |
|---|---|---|
| E75 | 75 ksi / 517 MPa | General drilling applications where the drill-string design supports this strength level. |
| X95 | 95 ksi / 655 MPa | Intermediate-strength option for specified tensile and torsional requirements. |
| G105 | 105 ksi / 724 MPa | Widely used higher-strength grade for deeper and directional drilling programs. |
| S135 | 135 ksi / 931 MPa | High-strength grade for demanding depth, load and drilling-envelope requirements. |
TOOL JOINT & CONNECTION
Connection geometry controls torque capacity and hydraulic clearance.
A drill-pipe request should identify the exact connection, tool-joint OD and ID—not only a familiar connection-family name.
NC
Numbered ConnectionCommon API connection family with the exact NC designation defined by the drill-string design.
IF
Internal FlushLegacy connection family still encountered in established drilling fleets and replacement requirements.
FH
Full HoleConnection family selected for applicable bore and torque requirements in compatible assemblies.
REG
RegularAPI connection family used in selected drilling components; exact size and compatibility require review.
CONFIGURATION OPTIONS
Specify the complete drill-pipe assembly.
Optional treatments must be compatible with the drilling program, casing-wear policy, connection and inspection acceptance criteria.
Internal Coating
Selected to reduce corrosion or hydraulic friction; coating system and inspection scope are order-specific.
Hardbanding
Applied to tool joints for wear control, with casing-friendly performance considered where required.
Make-and-Break
Workshop cycling of selected connections when included in the agreed preparation scope.
Cold Rolling
Thread-root or fatigue-sensitive surface treatment where specified and technically applicable.
Special Service
Sour or low-temperature requirements require explicit material, hardness and verification criteria.
Identification
Serial marking, color bands, tally information and traceable records organized for fleet control.
DRILLING ENVELOPE
Select from the calculated loads and operating risks.
Depth alone does not determine the drill pipe. Maximum overpull, surface torque, dogleg severity, buckling tendency, hydraulics, fatigue accumulation and planned inspection intervals all influence the configuration.
Vertical and directional wellsExtended-reach and horizontal drillingHigh-torque operationsFatigue-sensitive doglegsSour or corrosive environmentsLow-temperature operations
MANUFACTURING & QUALITY
Control pipe body, weld zone, tool joint and connection.
The inspection plan should follow the actual product configuration and order requirements.
01Specification, design and material review
02Upsetting, heat treatment and pipe-body testing
03Tool-joint machining and property verification
04Friction welding and weld-zone heat treatment
05Full-length NDT, dimensions and connection inspection
06Hardbanding / coating records, marking and final release
Typical available documents
Mill Test Certificate · Chemical and mechanical results · Pipe-body and weld-zone NDT · Tool-joint records · Dimensional report · Connection inspection · Hardbanding / coating records when ordered · Packing list · Third-party inspection records
DRILL PIPE RFQ CHECKLIST
Identify the assembly and the drilling duty.
A complete drill-pipe enquiry reduces connection mismatches and makes commercial comparison more meaningful.
Request a Drill Pipe Quote- 01Pipe-body OD, nominal mass, grade, range and quantity
- 02Exact tool-joint connection and required make-up condition
- 03Tool-joint OD, ID and any dimensional restrictions
- 04Upset type and applicable standard edition
- 05Internal coating, hardbanding and special-service requirements
- 06Inspection level, documentation, marking, packing and destination
PRODUCT & PROCESS VIEWS
Product views and manufacturing context.
Representative product, production and inventory views support preliminary identification. Final supply details are confirmed against the quotation.
START A CONVERSATION
Have a specification or product list?
Send it to OAK PIPE for technical and commercial review.