String & Casing Volume Calculator

String & Casing Volume Calculator computes internal capacity and annular volume for tubing, casing, and open hole across single or tapered string configurations. Get displacement and fill volumes for cementing jobs, completion fluid changes, and circulating operations without reaching for a spreadsheet. Results in bbl/ft, gal/ft, or m³/m, with running totals for the full string.

How It Works

Capacity (bbl/ft) = ID² ÷ 1029.4. Annular volume (bbl/ft) = (ID_outer² − OD_inner²) ÷ 1029.4, where diameters are in inches.

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

When You'd Use It

Before pumping a cement job or displacing to a completion fluid, engineers calculate exact internal and annular volumes so pump strokes land the fluid interface at the correct depth — a miscalculated volume can leave cement short of the shoe or displace fluid past the intended point.

Key Features

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