3X Engineering’s Mechanical protection of gas risers, Qatar

Overview

The aim of the job, performed in October 2022 by 3X ENGINEERING (3X) was to protect (mechanical protection + impact resistance) 19 gas risers (from 8" to 20" OD) on their splash zones and thus prevent further deterioration of the risers. The risers were in Offshore Qatar. They were straight line risers with a maximum operating temperature of 70°C, with a calculated pressure of 60 bars. It was decided to protect the risers areas using 3X composite solution REINFORCEKiT® 4D.

Scope of work

According to ISO 24.817 standard and 3X calculations, it was decided to apply 6 layers of REINFORCEKiT® 4D (using R3X95 resin) on each riser to protect them from impacts and corrosion issues. Surface preparations were completed using sandblasting to remove coating and create a good surface roughness (superior to 60μm Rz) and ensure a good bonding between the steel pipes and the composite solution. Then hygrometric conditions were checked and the whole prepared surfaces were cleaned with air blower. The composite applications were then completed following the main stages mentioned below (the procedure was the same for the 19 risers):

1. One layer of R3X95 resin was firstly applied on the prepared surface to ensure the good impregnation of the first tape layer.
2. Composite wrapping was then completed using Kevlar® tape impregnated with R3X95 resin. Six layers were applied on each riser with a repair length between 7220mm and 9200mm. A total of over 175m repair length using REINFORCEKiT® 4D product was installed on the 19 risers.
3. Last layer of R3X95 resin was applied all over the wrappings as finalization stage and id plate was installed for traceability.
4. Eight hours after, coating was applied on the composite protection.

Results

Samples of resin were taken during each tape impregnation for quality control and hardness measurements were performed and validated on site and in 3X offices. The 19 risers are now protected with REINFORCEKiT® 4D from impacts and corrosion issues that could affect their mechanical resistance. The design life for each riser for this composite protection is 20 years.