Tubing Stress Calculator

Tubing Stress Calculator screens a string against its published API ratings at every depth rather than at a single point, because the binding constraint is rarely where you would guess: tension governs at surface, collapse deep, and burst wherever the pressure differential peaks. Each check reports its own design factor against its own threshold, and the governing check — the single worst point anywhere in the string — is the headline, since a string is only as good as its weakest section. Design factors are shown and editable rather than hidden, and the collapse factor has no default at all: no published industry value exists for it, so the calculator asks rather than assumes. The collapse rating is reported with the regime that produced it, because a plastic-regime number is empirical where an elastic-regime number is theoretical.

How It Works

Design factor = rating ÷ load, at every depth. Tension load is buoyed weight below; burst load is internal minus external pressure; collapse load is external minus internal. Ratings per API 5C3.

See every formula worked through in detail on the Completion Engineering Formulas reference.

When You'd Use It

Before running a string, an engineer checks whether the selected weight and grade survive the worst load case at every depth — and which of burst, collapse or tension is the constraint that actually decides the design.

Key Features

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