1. What is a Stuck Pipe Stretch Calculator?

Definition: This calculator estimates the stretch length of a pipe when subjected to an axial force, based on Hooke's Law for elastic deformation.

Purpose: It helps drilling engineers determine pipe stretch in stuck pipe situations, which is crucial for calculating free point and determining where the pipe is stuck.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta L \) — Stretch length (meters)
• \( F \) — Applied force (Newtons)
• \( L \) — Original pipe length (meters)
• \( E \) — Young's modulus of elasticity (Pascals)
• \( A \) — Cross-sectional area of pipe (square meters)

Explanation: The stretch is directly proportional to the force and original length, and inversely proportional to the material stiffness (E) and cross-sectional area.

3. Importance of Stretch Calculation

Details: Accurate stretch calculation helps in determining the free point of stuck pipe, which is essential for fishing operations and preventing pipe failure during retrieval.

4. Using the Calculator

Tips: Enter the force in Newtons, original pipe length in meters, Young's modulus (default 2.1e11 Pa for steel), and cross-sectional area in m². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Young's Modulus?
A: It's a measure of material stiffness. For steel pipes, it's typically 2.1 × 10¹¹ Pa (210 GPa).

Q2: How do I calculate cross-sectional area?
A: For a pipe, A = π × (OD² - ID²)/4, where OD is outer diameter and ID is inner diameter.

Q3: What units should I use?
A: Consistent SI units are required - Newtons, meters, Pascals, and square meters.

Q4: Does this work for non-steel pipes?
A: Yes, but you must use the correct Young's modulus for the material (e.g., 69 GPa for aluminum).

Q5: How accurate is this calculation?
A: It's accurate for elastic deformation. For plastic deformation or composite pipes, more complex models are needed.