Inhibition Testing with High Strength Quench and Tempered Coiled Tubing

Abstract

Abstract High strength quenched and tempered coiled tubing (CT) has been developed and commercialized as far back as the 1990s, however in recent years it has grown to be a substantial, if not the main, type of CT in many markets. Testing programs for sour environment compatibility using inhibition exist for similar strength levels of conventionally produced coiled tubing and has been used as justification for utilization of Q&T coiled tubing with existing CT equipment and operations in sour environments. Quenched and tempered coiled tubing is given final heat treatments which yield a more homogeneous microstructure than conventional products. The field performance of this homogenized product has generally shown that the quenched and tempered tubing performs better in sour environments. This paper then explores the existing body of work with respect to accepted operational guidelines and sour gas testing of coiled tubing. A test program for 140-grade quenched and tempered coiled tubing was developed to explore sour compatibility using an inhibition system. The development and test results of the testing program are described in this paper. The paper concludes with field history of high strength quenched and tempered coiled tubing in Western Canada operations.