Differences in the design of refined oil pipelines and crude oil pipelines

Thread Content

Differences in the design of refined oil pipelines and crude oil pipelines I. Determination of pipeline capacity The capacity of crude oil pipelines is determined based on the production volume of oil fields and the processing capacity of refineries; in other words, it is set according to the amount of production. Refined oil is supplied in quantities based on demand; before designing the pipeline, it is necessary to investigate and assess the demand in the markets downstream of the pipeline. In principle, as much oil is transported as is demanded by the market, and only afterward is the volume of oil to be transported determined based on the production capacity of the refineries upstream. Furthermore, when determining the crude oil throughput, it is often calculated on an annual basis, as the production from oil fields and the processing capacity of refineries are relatively balanced. The demand in the refined oil consumption market is volatile and varies greatly, so it is unscientific to calculate based on annual throughput. II. Determination of the pipeline route For crude oil pipelines from oil fields to refineries, the design process focuses on selecting a route between these two points that features favorable topographical and geological conditions, as well as being relatively short. In determining the length of oil product pipelines, in addition to these factors, the location of the consumer markets must also be taken into account, with an effort to connect the consumer markets as much as possible. As a result, the length of the pipeline may increase, or the pipeline may need to pass through complex areas; a comprehensive analysis of the specific circumstances is required, followed by further evaluation before a decision can be made. III. Determination of the transport medium and sequence of transportation There is no sequential transportation in crude oil pipelines. In contrast, in the design of petroleum product pipelines, it is necessary to take into account the type of fluid being transported as well as the order in which different oil products are conveyed through the pipeline. At the same time, the relationship between market demand and operational feasibility must also be considered, so that the delivery of a certain oil product to downstream markets remains economically viable and feasible, even if the quantity is small or there is a high degree of mixing with other oils. On the contrary, in some cases it is necessary to consider the situation where the market does not require a certain type of oil, but that this oil is added to the sequence of sequential delivery as a separator between the other two types of oil in order to reduce mixing losses. For example, kerosene is added between the gasoline range and the diesel range to improve the quality of the blended fuel and reduce economic losses. IV. Mixed oil calculation and treatment Unlike crude oil pipeline design, refined oil pipeline design involves the issue of mixed oil calculation. Oil mixing represents a form of loss; due to the complexity of the mechanisms involved in oil mixing, there is no applicable theoretical formula to date. Although there are many empirical formulas, most of them have a limited range of applicability. Therefore, it is important to choose an appropriate formula. The mixed oil generated during transportation must be separated at the terminal station. All of these need to be carefully considered in the design. V. Determination of batches/quantities and storage capacity If there are too many batches with small quantities each, more oil mixing interfaces will be formed, and as a result, the proportion of mixed oil increases. In this case, some of the mixed oil cannot be directly blended into pure oil. If the number of batches is reduced and the batch size is increased, although the amount of mixed oil decreases relatively, the storage capacity at the starting and ending stations as well as at the intermediate transfer stations must be increased, which raises the initial investment. Therefore, the batch size needs to be optimized to achieve the best economic efficiency for the pipeline, and the storage capacity at each station is determined based on the results of this optimization. 　　Furthermore, the issue of distribution is important, as there are many distribution stations along the refined oil pipelines. The timing, duration, and volume of oil transfer at each station vary, and the operating conditions of the entire pipeline system are constantly changing. Therefore, it is necessary to conduct dynamic analysis of various operating conditions and determine the operational parameters based on the results of this analysis. 　　The safety requirements for refined oil pipelines are also higher than those for crude oil pipelines; leaks from refined oil pipelines pose a much greater threat to the environment, human life, and property compared to leaks from crude oil pipelines. Note: This article is excerpted from