Casing Design Calculator

Casing Design Calculator runs a string against several design scenarios at once rather than one condition at a time, because that is how casing is actually designed: the string has to survive the worst of a gas-filled burst case, a tubing leak, mud losses and cementing, and the governing constraint is rarely the same for every check. Each enabled case is evaluated at every depth against the pipe’s API ratings, and the result names both the depth and the case that produced the worst design factor — the answer that tells you what to change. Which scenarios to design against is industry convention rather than a formula, so the set ships as one published recommendation with every case individually switchable, and the collapse design factor has no default at all because no published industry value exists for it.

How It Works

For each enabled load case: design factor = API rating ÷ load, at every depth. The envelope takes the worst across cases per check. Burst is usually worst near the wellhead, collapse at depth.

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

When You'd Use It

When selecting weight and grade for a casing string, an engineer needs to know which scenario governs the design — a string that passes a pressure test may still fail on lost returns, and knowing which case binds tells you whether to change grade, weight or the mud program.

Key Features

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