Dacon Inspection Services recently completed a major pipeline inspection project in Nigeria. The project consisted of intelligent pigging of a 4” x 4.5km pipeline for Addax Petroleum one of the major international oil and gas exploration and production companies in Nigeria. Dacon was able to complete the project within 6 days using an auxiliary pump and water.
The scope of work included gauging and ultrasonic intelligent pigging of the pipeline. This was necessary in order to measure the remaining wall thickness, identify metal loss and related defects and anomalies, ascertain if the pipeline was still fit for purpose as well as calculate the remaining life of the pipeline.
The process of pipeline gauging was completed prior to launching the intelligent pig. A bidirectional gauging pig fitted with a slotted aluminium gauging plate was mobilized in order to check the minimal bore of the pipeline.
Once the gauging plates had passed through the line undamaged, it was obvious that the passage was clear of obstructions and intrusions, allowing the launching of the intelligent pig.
The pipeline inspection project was executed inline using Dacon’s regular procedures and under international standards.
Dacon is a market leader in pipeline pigging and specializes in using ultrasonic intelligent pigging tools to inspect hard to access and so called ‘unpiggable’ pipelines with no launching and receiving facilities. UT Intelligent Pigs are preferred for various reasons, including their smaller size, lighter weight and the easier mobilization process. If the length of the line permits it then UT is the preferred option compared to Magnetic Flux Leakage (MFL) pigging for its higher accuracy and cheaper cost for the customer.
Dacon’s UT Intelligent Pigs provide a highly accurate value for local wall thickness and can be used for comparing actual wall thickness with nominal wall thickness, verifying previous inspections, fitness for service evaluations and baseline surveys.