Landslides are one of the main threats in maintaining pipeline integrity and depend directly on natural geological and geotechnical conditions. External factors such as weather, rainfall, and others, can trigger land movements and displace the pipeline.
The Ecuadorian OCP (Heavy Crude Oil Pipeline) is a buried pipeline going in an East to West direction, crossing 485 kilometers of the Ecuadorian territory. It starts in the Amazon Region (approximately 300 meters above sea level), and then climbs the Andes Mountains (4060 meters above sea level in its tallest portion), to then descend to the shores of the Pacific Ocean. The OCP pipeline crosses many regions with varying climates, varying rainfall patterns, variable morphologies, diversity of soils, and areas affected by tectonic faults, among others.
In order to prevent pipeline failures, OCP Ecuador has instituted programs to perform preventive and corrective actions in order to handle the following geological concerns:
• Intervention of a specialized geotechnical team to identify and monitor critical points along the pipeline route. This team identifies unstable sites based on the observations of cracks, land movements, or other visual deformations of the pipeline route and its surroundings.
• Upkeep of the preventive program.
• Execution of third-level studies required to understand specific unstable zones in detail: nature of the subsoil, underground water level, geo-mechanic characteristics, stability factor, and stabilization works.
• Geotechnical instrumentation used: inclinometers to search the spread of movement, shifting direction, speed, (landslide location); strain gauges for preventive control of pipeline strain, alert levels, efficiency of stabilization works; and topographic surveys to monitor superficial movements.
• Data processing and mapping on GIS Software.
• Annual over-flights to detect massive landslides.
• Internal inspectors (online-ILI) providing a wide range of information: geometry measurements, curvature monitoring, pipeline displacement, etc. In addition, it allows detection of probable zones depicting soil movement.
The purpose of this technical paper is to present the methodology applied by OCP Ecuador to prevent failure of the pipeline along its route.