NEOTECTONICS IN HYDROCARBON TRANSPORTATION LINES CORRIDORS THE NEED OF A DETAILED STUDY

摘要

The Colombian pipeline network is exposed to the permanent activity of geological processes that happen in the country, due to the location of the country in the north-western corner of the South American plate -where it is interrelated to the Nazca and Caribbean plates-, the Andean zone is subject to compression strains that cause the uplifting of the mountain ranges and with it their slopes, which eases the instability processes. On the other hand, since the country is located in the inter-tropic zone of the planet, where the rock deterioration processes are harsher, landslides are more frequent, this together with the condition of strains, makes instability something fairly common. Evidence on pipelines for hydrocarbon transport is obtained from the fault activity, like this: The Santiago - El Porvenir oil pipeline, that rises from the plains to the mountain range, in December of 1991 a sudden linear landslide of the pipe was evidenced in the Santiago field (flat zone in the plains, south of Mani, Casanare), the position of the topographic control markers of the line was verified and a terrain shortening of 22.5cm was found in the markers located both sides of the Yopal fault, for this reason the pipe had moved from the area into the launching trap of Santiago, located 60km away from the trace of the fault. In the Medellin - Cartago pipeline, in the crossing above the Cauca river, in the area of La Felisa, there is a 2.57m misalignment, in relation to the construction location, where the towers were aligned with the direction of the pipe, around 25 years ago. Nowadays the curve in the pipe suspended from the bridge cables can be observed, which, given the length of the bridge of around 200m doesn't affect the mechanical conditions of the pipe. Along the Cauca river passes one of the geological faults of the Romeral system. (figure 5). Due to the tracing of the initial pipes of the Cusiana Field, in the late 90s of the past century, a shortening of more than 2m of distance was detected between the geodesic spots of the National Geodesic Network, Taura and Mena, that are found beside the Guaicaramo faults system, these spots were built in the early 50s and located with first order geodesic precision procedures.