Research on Some Problems about Oil and Gas Pipelines Crossing the Loess Gully or Slope

Apart of the West-East Gas Pipeline and Product oil Pipeline projects has to traverse the Loess Plateau where the regional topography is complicated, loess gullies or slopes are more. There are great difficulties for laying pipelines due to the Loess Plateau. Using large scale excavation method for the loess gully or the slope, the project quantity is not only large, but also the destruction on the environment and vegetation is serious. In addition to these, the landform restoration and the protection of hydraulic surroundings are rather difficult. So, the crossing of long-distance oil and gas pipelines in the loess gully or the slope adopts the combination of inclined well and horizontal tunnel. Choosing the design parameters to ensure security crossing of pipeline is one of the important topics. According to the slope stability analysis, some problems about oil and gas pipelines crossing the loess gully or slope were studied based on the theory and numerical methods in this paper, such as the selection of non-linear elastic loess model, the determination of surface wellhead position, the reasonable section of inclined well, the reasonable position of the operating pit, the suitable support method under the inclined construction. The obtained conclusions are useful to the design and construction for gas and oil pipeline engineering.