1. What is the Stuck Pipe Stretch Calculation?

The Stuck Pipe Stretch calculation is used in oil and gas drilling operations to determine the amount of stretch in a drill pipe when a specific pull force is applied. This helps in assessing the point where the pipe is stuck and determining the appropriate force needed to free it.

2. How Does the Calculator Work?

The calculator uses the stretch formula:

Where:

• \( Pull\ Force \) — Applied force in pounds (lb)
• \( Weight\ per\ ft \) — Weight of the pipe per foot in pounds per foot (lb/ft)
• 735294 — Constant derived from material properties of steel

Explanation: The formula calculates the elastic stretch of the drill pipe based on the applied force and the pipe's weight per foot, using the modulus of elasticity for steel.

3. Importance of Stretch Calculation

Details: Accurate stretch calculation is crucial for determining the free point of a stuck pipe, planning fishing operations, and avoiding pipe damage during recovery operations. It helps drillers apply the correct amount of force to free the pipe without causing additional problems.

4. Using the Calculator

Tips: Enter the pull force in pounds (lb) and the weight per foot in pounds per foot (lb/ft). Both values must be positive numbers. The result will be displayed in inches.

5. Frequently Asked Questions (FAQ)

Q1: What is the constant 735294 derived from?
A: This constant comes from the formula: 1,000,000 × (π/4) × (1/E) × 12, where E is the modulus of elasticity for steel (30,000,000 psi).

Q2: When should this calculation be used?
A: This calculation is specifically used when a drill pipe becomes stuck during drilling operations and you need to determine how much the pipe will stretch under a given pull force.

Q3: What are typical values for weight per foot?
A: Drill pipe weight per foot typically ranges from 10-25 lb/ft, depending on the pipe size, grade, and tool joints.

Q4: Are there limitations to this calculation?
A: This calculation assumes uniform pipe properties and doesn't account for friction, doglegs, or other downhole conditions that might affect the actual stretch.

Q5: How accurate is this calculation in field operations?
A: While this provides a theoretical calculation, field measurements may vary due to factors like temperature, mud weight, and actual pipe condition. It should be used as a guide rather than an absolute value.