A non-intrusive, non-contact method for inspecting ferrous pipelines. MTM covers 100% of the pipeline and has been proven in industry use since 2001.
MTM-G Magnetic Gradient Tomography Method
The new generation of MTM. A non-destructive testing solution for anomaly detection and pipeline integrity evaluation, for above-ground, underground and offshore pipelines of all types and sizes.
Overview
- Agreement with conventional NDT
- 90–97%
- Subsea inspection depth
- Up to 1,500 m
- Offshore probability of detection
- Over 80%
- Minimum pipe diameter
- 50 mm
MTM-G is based on the Villari effect: the change in magnetisation of a ferromagnetic metal when it is subjected to mechanical deformation or stress. A portable magnetometer scans the pipeline and measures its magnetic field, and changes in that field are used to identify anomalies and stress concentrations in the pipe.
Advantages of MTM-G
No blind spots
Inspects the entire length of a pipeline, including bends and turns.
No interruptions
Pipelines stay in operation during inspection.
No special preparation
No cleaning or depressurisation of the pipeline is needed.
Detects all types of anomalies
Finds anomalies inside and outside the pipe, including metal loss, corrosion and cracks.
Identifies stress concentrations
Locates areas of stress concentration, where failure is most likely.
Accurate and reliable
Shows 90–97% agreement with conventional NDT methods.
Subsea MTM-G
Subsea MTM-G is a variant designed for underwater pipelines. It inspects pipelines up to 1,500 metres deep and detects metal anomalies such as metal loss, corrosion and cracks.
Combining the MTM-G anomaly map with a seismic activity map adds further analysis and integrity assessment capability.
Subsea MTM-G inspects offshore pipelines along their entire span with a probability of detection above 80%.
Scanning and calibration
- We locate the pipeline axis below the ground surface.
- We scan the pipeline with a portable magnetometer that records magnetic data and GPS tracks automatically.
- We process the data and review it for quality.
- If data quality is not acceptable, we rescan the pipeline.
- We deliver a final report listing the dangerous (anomalous) areas of the pipeline, located on the map with their danger degree.
Requirements and limitations
| Distance from pipe axis to magnetometer | 25D to 30D maximum |
|---|---|
| Operating pressure | No minimum or maximum |
| Pipe diameter | 50 mm minimum, no maximum |
| Wall thickness | 2.8 mm minimum, no maximum |
| Section length | No limit |
| Access | A clear path at least 1 m wide for the operator to walk above the pipeline |
Technology partner
MTM-G is developed by IGSAT. El-Eman delivers MTM-G inspection to pipeline operators in Egypt.
Technical documents
Get a quote for MTM-G
Tell us about the asset and location. We will reply with scope and pricing.
Other services
Real-time inspection of pipelines, tanks, vessels, heat exchangers, boilers, offshore platform legs and risers, without interfering with the operating process.
An internal pipeline corrosion monitoring system that combines a weight loss coupon with liquid and solid sample collection, for an accurate assessment of the pipeline’s internal condition.
A patented catalyst technology that reaches product purity of up to 1 ppb in one or two stages of direct oxidation, at 3 to 10 times lower cost of ownership.
Thin-film intumescent coatings that protect steel and wooden structures for up to 120 minutes in a fire, giving firefighters and rescue services time to evacuate people.
