The Development Characteristics Of Water Damage Hazards And Its Risk Assessment On Oil And Gas Pipeline In Lunnan-shanshan Section

With the rapid development of economy in our country, the demand for oil andnatural gas increases dramatically and thus the long distance pipeline used widely totransport oil and gas. However, the damage of geological hazards on pipeline has becomea problem that not allow to ignore. Surveys indicated that the accident frequency of waterdamage hazards is far more than others and has become the main types, especially in thenorthwest.In this paper, three long distance oil and gas pipelines in the Lunnan-Shanshansection as an example, and a investigation about the meteorological, hydrological,landform, stratum lithology, geological structure, and hydrogeologic conditions alongthese pipelines is made. And a study about the development of the water damage hazards,such as type, distribution, formation condition, the damage on pipeline is made. Waterdamage occured in the river and channel hazards of2points and water damage occured inslope of2points which bring about greater damage on pipeline are chosen. And aselective analysis on geological environment conditions, formation conditions,influencing factors, the damage on the pipelines is made. Water damage occured in theriver and channel, according to different damaged area can be divided into five types,namely the riverbed local scour, riverbed incised, bank collapse and bank erosion, riverdiversions. And riverbed incised is the main type, which cause pipeline buried depthbecomes shallow even naked. Water damage occured in the slope is a kind of disasterphenomenon that the loss of surface soil and water caused by surface flow erosion andpipe embankment washed out cause pipeline buried from depth to shallow.The damagedpart of water damage occured in the river and channel is relatively fixed.The current focuson washing certain part where the pipeline through the viver or channel long time.And thescale is controlled by the catchment area. The damaged part of water damage occured inthe slope is wandering and swaying, but not fixed. The scope of washout is larger and theincised depth is shallow.Referencing for the related theory of geological hazards risk evaluation, this paperdiscusses the suitability of qualitative and semi-quantitative risk assessment method.And the paper on the basis of Oil And Gas Pipelines Geological Disaster RiskManagement Technical Specifications, combine with statistical analysis of waterdamage hazards of386points in The Report of West Pipeline Company Geological Disaster Survey And Prevention Plans of Pipelines in Gansu Province Hexi Corridor.Two methods are used to evaluate the risk of water damage hazards of50points, thecomprehensive evaluation result corresponds to the actual development situation of waterdamager hazards. The semi-quantitative evaluation method is chosen mainlysupplemented by qualitative evaluation method for the risk assessment of water damagerhazards. This method has important practical significance for risk evaluation of waterdamager hazards of oi land gas pipeline in the Lunnan-Shanshan section, and has agood reference for the risk assessment of water damager hazards of pipeline in similararea.