NMDP-Non-Magnetic Drill Pipe

1. Definition & Purpose

Non-Magnetic Drill Pipe (NMDP) is a specialized drill string component designed to minimize magnetic interference with Measurement While Drilling (MWD) and Logging While Drilling (LWD) tools. It ensures accurate downhole surveying and directional control in critical wellbores.

2. Key Features & Advantages

FeatureBenefit
Low Magnetic PermeabilityPrevents distortion of compass-based MWD/LWD readings.
High-Strength AlloysMaintains mechanical performance (e.g., ASTM A707, Monel, or Cu-Ni alloys).
API-Compliant DesignInterchangeable with standard drill pipes (API 5DP/7-1).
Corrosion ResistanceIdeal for H₂S/CO₂ environments (optional NACE compliance).

3. Technical Specifications

  • Standard: API 5DP (with supplemental NMDP requirements).

  • Magnetic Permeability: <1.05 μ (vs. >1.2 μ for carbon steel DP).

  • Grades: Non-magnetic equivalents of E-75, X-95, G-105.

  • Dimensions: Common sizes 3½" to 6⅝" OD, Range 2/Range 3 lengths.

NMDP-Non-Magnetic Drill Pipe