Case Study

14" Remote Tecno Plug, NGL-4 Plant, Mesaieed Industrial City, Qatar

Tool - Remote Tecno Plug Isolation Tool

Location - Qatar

Operating Environment - Onshore, Gas Plant

Pipeline Medium - NGL

Activity - Maintenance

Talk to an expert

STATS and QP team working on deploying a remote tecno plug

STATS Group were required to provide double block and bleed isolation on a 14” NGL pipeline as part of a scheduled plant shutdown, facilitating critical maintenance of an ESD valve. Qatar Petroleum approached STATS Group to assist with providing a safe isolation at their fourth Natural Gas Liquids Plant (NGL-4) in Mesaieed Industrial City, Qatar.

Avoiding a 40km NGL Pipeline Purge: Remote Tecno Plug ESD Valve Isolation at Qatar's NGL-4 Plant

Scheduled maintenance of an ESD valve on a live NGL pipeline would normally mean one thing: flaring the hydrocarbon content and nitrogen purging the entire line before anyone could safely begin work. At Qatar Petroleum's NGL-4 plant in Mesaieed Industrial City, that meant 40 kilometres of pipeline. The time, cost, and environmental implications of that approach made it unacceptable.

STATS was contracted to provide a double block and bleed isolation using a Remote Tecno Plug - eliminating the need to depressurise the line and allowing the ESD valve maintenance to proceed safely on the live system.

The Challenge: ESD Valve Maintenance Without a 40km Pipeline Purge

Qatar Petroleum needed to carry out critical maintenance on an ESD valve on their 14" NGL pipeline at the NGL-4 plant in Mesaieed Industrial City. Under a conventional approach, the entire 40-kilometre pipeline would need to be made hydrocarbon-free before any intervention could take place - requiring NGL flaring followed by a full nitrogen purge of the line.

The operational, procedural, time, and environmental implications of purging 40 kilometres of NGL pipeline were significant. A solution was needed that could provide a verified double block and bleed isolation on the live, pressurised system - without requiring the line to be taken out of service.

Highlights

Conventional repair would have required flaring NGL and nitrogen purging 40 kilometres of pipeline - eliminated entirely.
Custom 4-module Remote Tecno Plug designed and manufactured in Aberdeen based on a detailed site survey.
Full Factory Acceptance Test completed in a purpose-built fixture replicating the client pipeline configuration.
Tool navigated past 4 valves, a barred tee, a monolithic joint, and a 5D bend before setting at the ESD valve.
ELF radio communication used for reliable tracking and accurate positioning - no tethers required.
Isolation monitored for 24 hours before Isolation Certificate issued - plug then used as reinstatement test boundary.

STATS and QP team working on a remote tecno plug in Mesaieed Industrial City Qatar

The Solution: A Custom Remote Tecno Plug Built for This Pipeline

STATS deployed a specialist field technician to carry out a detailed site survey at Mesaieed, collecting data and critical dimensions from the pipeline system. Based on those findings, STATS designed and manufactured a custom Remote Tecno Plug at their Aberdeen headquarters.

The tool was configured in a four-module arrangement - the result of design analysis showing this to be the optimal configuration for the pipeline geometry. Before mobilisation, a full Factory Acceptance Test was carried out in Aberdeen in a purpose-built test fixture created specifically to replicate the client's pipeline configuration.

Through Four Valves, a Barred Tee, and a 5D Bend

Onsite, the Remote Tecno Plug was deployed from an 18" launcher and pigged through the system. The tool successfully navigated past four valves, a barred tee, and a monolithic joint before negotiating a 5D bend and setting immediately beyond the ESD valve at the required isolation location.

Positioning and setting were achieved using STATS' through-wall ELF (Extremely Low Frequency) radio control system, which provides reliable tracking and accurate placement without the need for tethers or specially modified pig-trap doors.

24-Hour Hold, Isolation Certificate, and Reinstatement Test

Once set, the plug was monitored continuously for 24 hours. Following successful verification of the double block and bleed isolation, an Isolation Certificate was issued to all parties. Qatar Petroleum's maintenance team then carried out the required ESD valve work.

On completion of the maintenance, the Remote Tecno Plug was used as a test boundary to perform a reinstatement pressure test on the pipeline. The plug was then unset and pigged back to the launcher for demobilisation.

STATS Group demonstrated a professional approach throughout – right from bidding and handling of technical queries, to on time mobilisation of STATS resources and contract execution. The site personnel allocated to this project deserve special praise for their commitment and dedication, working alongside QP operations in the most co-operative manner with the utmost regards to safety.

Head of Business Planning, Gas Operations

Qatar Petroleum