The ALMA G2 — Airborne Laser Methane Assessment Generation is a fully integrated aerial methane inspection package. Purposebuilt for inspecting methane gas infrastructure, it consists of a Pergam ALMA G2 gas sensor, mounted on helicopters. Pergam-Suisse AG and Regional Air Services performed an airborne natural gas pipeline leak inspection for Transgaz, Romania. The Pergam-Suisse ALMA G2 natural gas leak detection system was mounted on an Agusta Bell 206 JetRanger provided by Regional Air Services. The inspection covered approximately 1150 Km of pipeline in Romania. Over 10 hazardous natural gas leaks were detected during the inspection. Some Large to small methane gas detections were found at what appear to be natural gas well facilities. These detection points will require a re-inspection.
Few tiny or very tiny methane gas detections were found — normally these detections are considered nonhazardous and have a low probability of being a leak in the natural gas pipeline as they are in the range that occurs naturally. The report details all found detection points during the inspection.
Map of Detection Points
Description of ALMA G2
ALMA G2, Airborne Laser Methane Assessment Generation 2, is an instrument for remote detection from helicopters of an increased methane gas concentration in ambient air (the gas cloud coming from a leak or other sources).
is based on an infrared laser with radiation wavelength ~ 1650 nm of which Methane absorbs. A laser beam is emitted from the Optical Unit (OU) and hits a topographic object (soil, grass, trees, concrete, asphalt, etc.). The system analyzes the laser light back scatter to determine how much if any of the laser energy was absorbed by the methane in natural gas. A unique detection algorithm allows for real-time measurement of total methane content along the laser light path from the OU to the topographic object.
The system compensates for atmospheric methane using a laser rangefinder. The D-Box and operator laptop with C-Box (control panel) are for system control, data and video storage, and data analysis. The system continually records the inspection data including GPS location information. The on-line software is used for system control and real-time inspection data monitoring from the laptop. The data process software is used for off-line review of inspection data and generation of a report. The system includes a Digital Video Recorder, up to four video cameras, and a monitor to assist the pilot in aiming the laser. The operator monitors the data provided by the system to confirm gas detections, helps the pilot with navigating along the pipeline, and determines if an area needs further inspection.
Table 1 - ALMA G2 Technical Parameters
Pictures of ALMA G2 Installed on JetRanger Helicopter
The ALMA G2 system consists of 4 parts:
Optical Unit (Housing the Laser, Rangefinder, and Cameras)
D-Box (Housing the Digital Video Recorder and Electronics)
Laptop with C-Box (Control Panel) & GPS
Pilot Monitor
Figure 2 – ALMA G2 Optical Unit Figure 3 - JetRanger with ALMA G2 Optical Unit (grey) Mounted to Belly Figure 4 – ALMA G2 D-Box Secured to Backseat with Seatbelt Figure 5 – ALMA G2 Laptop with C-Box. Held by Operator in Either Front or Back Seat
