Advanced oil exploration methods like hydraulic fracturing, horizontal drilling or deep wells raise the bar for the quality demands of OCTG tubings. Especially collapse resistance of a tube is a major concern in some environments and therefore must be fulfilled to avoid catastrophic failures. The API 5CT standard defines technical delivery conditions for steel pipe used as casing or tubing for wells and includes ultrasonic testing criteria for different tube grades. As an add-on, API Bulletin 5C2 describes performance properties of Oil & Gas pipes. Formulas and procedures for calculating these values are given in Bulletin 5C3: Measurement values like a tube´s inside and outside diameter (ID, OD), ovality (OV), wall thickness (WT) and excentricity (EX) are needed to calculate parameters like e. g. yield strength or collapse resistance of a tube. GE´s ROWA-WT ultrasonic testing system is capable of fast and reliable dimensional check (GEO) of tubes and pipes. This paper describes the principle of operation of a ROWA as well as the method used for inline calculation of geometric values for API collapse and burst requirements.

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