Airborne LIDAR Pipeline Inspection System (ALPIS) Mapping Tests

Overview

Main Objective

The primary objective of Phase IV is to extend the current ALPIS capability to the detection of volatile emissions from liquid transmission pipelines. The Airborne LIDAR Pipeline Inspection System (ALPIS) is an airborne remote sensing system for detecting leaks associated with natural gas and hazardous liquid pipelines. Data collected with ALPIS can be incorporated into a geographic information system (GIS) to create mapping databases. Project goals are to achieve survey speeds of up to 150 miles per hour and cost equal to or less than much slower survey methods currently available.

Public Abstract

The Airborne LIDAR Pipeline Inspection System (ALPIS) is an airborne remote sensing system for detecting leaks associated with natural gas and hazardous liquid pipelines. ALPIS uses differential LIDAR, (Light Detection and Ranging), to detect the presence and concentration of hydrocarbons in the atmosphere. The system employs a digital camera and a global positioning system (GPS) to provide visual, cartographic representations of surveyed areas. Data collected with ALPIS can be incorporated into a geographic information system (GIS) to create mapping databases. Project goals are to achieve survey speeds of up to 150 miles per hour and cost equal to or less than much slower survey methods currently available.

Once ALPIS is completed, pipeline operators will have at their disposal a fast, efficient, and accurate tool for detecting and mapping natural gas and hazardous liquid pipeline leaks. ALPIS will also allow operators to survey their pipelines much more quickly than is possible with conventional technologies. In addition, cost per mile of pipeline surveyed is also expected to be comparable to or below that associated with currently available technologies.

Future activity in the ALPIS project is aimed at moving the technology from an engineering research prototype to a commercialized leak detection and mapping system that the pipeline industry can use. Therefore, a major objective is to determine the system's reliability and accuracy in locating and mapping leaks associated with natural gas pipelines. This requires the LIDAR sensor to locate a high percentage of leaks that can be verified by ground surveys while minimizing false positive detection. To accomplish these goals, future work will involve upgrading some of the hardware and software associated with ALPIS and performing flight tests in coordination with the pipeline industry.

Summary and Conclusions

Based on the data provided, leaks at many of the leak sites were successfully detected. Leak rates of 500 scfh or higher were detected at least 50% of the time. Leak rates of 100 scfh were only detected 15% of the time. Leak rates of 15 scfh and 10 scfh were only detected about 5% of the time. The 1-scfh leak was never detected. There were also a large number of "false positive" leak sites identified by the equipment providers. Some of the equipment providers made system improvements during the week including repairing malfunctioning equipment, mechanical modifications to improve performance in field applications, and developing improved data handling schemes. Other modifications have been defined for future work by some of the equipment providers.

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