Real time tubing inspection during hoist interventions was implemented in South Oman in late 2007. It utilizes the principle of electromagnetic pipe inspection. The technique is similar to conventional yard based electro magnetic tubing inspection, the difference being that yard inspection is performed on the ground whereas real time tubing inspection is performed on the well. It provides scientific assessment of tubing condition in real time.

The purpose was to provide a quick, reliable and an objective method of evaluating the tubing condition. The past practice of visual inspection of pulled tubing by hoist crew often resulted in misjudgment of tubing condition. This led to either re-running flawed tubing or wholesale rejection of good tubing. The obvious consequences were premature well failures due to loss of completion integrity or unnecessary tubing transportation costs and associated HSE risks. It also strained the conventional system of yard inspection, which was unable to cope up with the huge work volume as a consequence of excessive tubing rejection by the hoists.

The technique was utilized during 130 hoist interventions in 2008 across the fields of South Oman. This represents approximately 10% of total hoist interventions in South Oman wells annually. Immediate gains were realized in terms of reduction in tubing consumption volume, reduction in yard inspection volume, prevention of pre-mature well failures due to loss of tubing integrity, reduction in transportation costs and HSE risks.

Above all it helped in collating tubing failure data in a systematic manner, which was not possible with centralized yard inspection as keeping track of rejected joints on well wise basis was not possible. The database allows segregation and analysis of tubing failure data based on field, age & failure depth basis. With sufficient data availability, it has potential to enable better understanding of pipe failure mechanisms and allow implementation of prevention steps.

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