QT-16Cr Coiled Tubing: A Review of Field Applications and Laboratory Testing

QT-16Cr coiled tubing was introduced as a commercial product in the spring of 2004. This high strength corrosion resistant alloy product was developed to offer a cost effective coiled tubing solution for both injection and secondary production applications in wet CO₂ environments where carbon steel products may not be suitable.

This paper focuses on the results of two years of field applications and laboratory testing with the intent of defining the suitability and limitations of QT-16Cr as a completion string subjected to varying concentrations of CO₂, H₂S, chlorides and pH. The combination of actual fluid and gas analysis from wells where QT-16Cr has been employed will be compared to autoclave testing which simulates downhole conditions with applied stress on the tubing.

This paper also addresses the manner in which QT-16Cr has a positive effect on production system economics using several S. Texas wells as examples.

A review of field tests utilizing QT-16Cr as work strings will be covered. Attributes will be reviewed inclusive of abrasion characteristics when run inside 13 chrome production tubulars and low cycle fatigue performance data.

Both operators and service providers that have potential applications for corrosion resistant alloy coiled tubing should have interest in this update and overview regarding the performance of QT-16Cr coiled tubing.