Quest Integrity’s In-line inspection of challenging pipelines in West Africa

Project Overview

Quest Integrity has recently successfully completed the ultrasonic in-line inspection of four difficult-to-inspect dual-diameter pipelines for a major Operator in Nigeria, West Africa. The inspections were required to detect and quantify remaining wall thickness, internal and external metal loss, and deformations ensuring they were fit-for-service as any unplanned downtime would severely hamper production.

Challenge

The pipelines were constructed in the mid-1990’s and had no pigging history due to the lack of pigging facilities. In addition, the pipelines had dual diameters with unknown ID restrictions, and presence of short radius bends.

Solution

A two-man team mobilized offshore hand carrying Quest Integrity’s lightweight and compact inspection tools to the site. Inspection of the four pipelines were carried out as follows: prior to the inspection, pipelines were cleaned using a progressive non-aggressive pigging program. The InVista™ inspection tool was launched and upon retrieval, the UT measurement data was downloaded and prepared for initial field analysis. Within hours after the inspection, the customer was presented a site completion report indicating data quality, pipeline cleanliness and location(s) of debris. Quest Integrity delivered a level 2 fitness-for-service (FFS) final report in accordance with API 579 to the client within 45 days.

Conclusion

The Quest Integrity InVista™ technology overcomes challenges associated with traditionally difficult-to-inspect or unpiggable pipelines. The inspection delivered 100% axial and circumferential ultrasonic wall thickness measurements as well as geometry data. The client was pleased with the complete inspection of their pipelines. Some of the benefits that the client noted were:

• Improved safety and flexibility: tools are extremely lightweight and short; no lifting equipment was required.

• Simplified inspection process: high-resolution ultrasonic sensors acquire direct measurements providing geometry and wall thickness data in a single inspection run; no gauging and caliper pigging is required.

• 30% local collapsibility: collapsible design allows for full navigation of pipeline with a reduced local cross-section up to 30%.

• Reduced operational risk: InVistaTM tools are low friction, neutrally buoyant, un-tethered, and bi-directional.

• Secondary tool always available: a backup tool will be on-site and available at no extra cost to the client. This is in order to increase project efficiency and minimize delays

• Provides hard data: quantifiable direct UT measurements in wall thicknesses ranging from 1.2mm to 50.8mm