The oil and gas industry frequently uses pipeline simulation to model the flow of crude oil. For an accurate estimate of the pipeline capacity, it is essential to consider the heat effects of the environment on the pipeline as well as how the oil properties are affected by ambient temperature. This blog explains how to model various heat transfer mechanisms by integrating heat transfer elements into the pipeline flow network, along with the use of a new operating fluid material, Flownex.
Crude Oil Pipeline Simulation Using Flownex
Flownex specializes in fluid and thermal systems, providing engineers with a comprehensive tool for designing and analyzing complex pipelines. It offers a user-friendly platform for simulating the flow of crude oil, considering factors like pressure drops and temperature changes, enabling accurate modeling of real-world pipeline conditions. Flownex replicates fluid behavior in pipelines using predefined and custom components to represent crude oil characteristics. Users can input specific parameters, such as pipe dimensions, to simulate the flow and identify areas that may require attention during the design or operation phase.
Below is a simple diagram illustrating the process of transporting crude oil from offshore to port facilities.
The flow network in Flownex for modeling the crude oil pipeline includes the pipeline route from the oil tankers to the onshore storage facility through the marine floating terminal and booster pump station on land. Nodes are used to connect elements in the flow network and also to specify important geographical pipeline information, like elevation. Next, the user inputs the physical properties of the crude oil, such as viscosity and density, followed by the specification of pipes, which are assigned to individual pipes based on pipeline specifications, including diameters, lengths, roughness, loss, etc. Users can add pumps and other necessary components to the model after setting the operational conditions, such as temperature and pressure.
Modeling Thermal Impact on Crude Oil Material Properties
We can use Flownex to simulate how environmental thermal factors, like ambient temperature, affect the properties of crude oil in pipelines and the flow rate within the pipeline. To do this, we need to create a new custom-defined fluid material that accounts for temperature-dependent properties, such as viscosity. We consider the oil viscosity as a linear function of v(T) = 2.064 - 0.006 T kg/m.s., which is influenced by the ambient temperature T. So, the oil flow rate will be dependent on the temperature of the environment.
Next, the new fluid material will be assigned to one of the flow elements, like a pipe, as shown, and then it will be used as the operating fluid for every component of the oil pipeline in the flow network.
You can find another video that describes the details of adding new fluid material to Flownex by clicking the link at the bottom of this blog post.
Modeling Ambient Temperature Impact Along Oil Pipeline
Due to the pipeline's length, the ambient temperature significantly influences its operation. We can enhance the current flow network by incorporating heat transfer elements to simulate heat conduction and thermal inertia in the pipe walls. Integrating these elements into the flow network will enable the prediction of realistic pipeline flow rates, facilitating efficient and reliable design. Simulation results provide valuable insights for enhancing the performance of oil pipelines.
Three composite heat transfer elements were added to the flow network to account for heat conduction and heat convection both upstream and downstream of the elements. These elements are placed in three important sections of the pipeline: preceding the terminal, ahead of the booster station, and before the storage facility, as shown.
You can evaluate the flow delivery of the crude oil pipeline with and without heat transfer elements after completing steady-state simulations in Flownex (illustrated below). Heat transfer components give the oil pipeline a more realistic capacity, which is crucial for scheduling at the storage facility. Additional information from Flownex is available, like the distribution of variables that can be used to optimize pipeline performance, such as oil flow velocity and temperature, pressure, and pressure loss, throughout the pipeline.
The following video outlines the detailed process for integrating composite heat transfer elements into the flow network of the crude oil pipeline in Flownex, defining and utilizing a new custom fluid operating material with temperature-dependent properties, and assessing the impact of ambient thermal factors on the pipeline flow rate.
You can view another video that walks you through adding composite heat transfer elements to the pipeline in Flownex by clicking the link at the bottom of this blog post.
You can click this link to view the video on YouTube: https://youtu.be/3mcfvf3XLN4
YouTube video explaining how to define a new custom fluid material in Flownex: https://youtu.be/I1DRWjc9_Ro
Blog: https://blog.ozeninc.com/resources/how-to-add-a-new-temperature-dependent-fluid-material-in-flownex
This YouTube video explains how to incorporate composite heat transfer elements in Flownex: https://youtu.be/2QGl0y5tQkM