Investigating the cause of failure in coiled tubing after acidizing operation (real case)

Oil Exploration Operations Company (OEOC) is one of the most reputable private companies in the upstream sector of Iranian oil and gas industry. OEOC has obtained latest technical knowledge and vast experiences in the upstream of oil and gas projects. The company commenced its operation in two different fields of exploration operations and integrated drilling services. In one of acidizing operation was found that in addition to the low tube working hours the roll-on and cutting operation of the connector was easier than the previous tubes. To investigate this problem Optical Metallography test, Tensile test, Hardness test, Flattening Test and Flaring Test were defined. after evaluating the test results and checking with the operation unit, it was found that this tube has been used in several previous operations for widespread acidizing, which is also not a standard solution for acid, so reduces the life of the tube.

Keywords:

Coiled tubing , Failure , Acidizing , Tube life