Introduction to Onshore Pipeline Engineering

Pipeline is series of piping system which can be laid underground or aboveground to transport fluid (whether liquid or gas) from one point (source) to another point as a terminal point over the long distance. This pipeline is governed by different codes and standards from piping system. As we know, for example, process piping is governed by ASME B31.3 while power piping is by ASME B31.1. For Gas transmission and distribution piping system, it will govern by ASME B31.8, while for Liquid transportation piping will be designed as per ASME B31.4.

Designing onshore pipeline will involve several steps which starting during conceptual design stage, followed by FEED (Front End Engineering Design), Detail Design, Construction and pre-commissioning, and ended up with commissioning of the entire pipeline system and ready to put into operation or services.

During the conceptual design of the pipeline, normally we have received from the client the basic idea about the works, or we can say the Project overview, such as what would be the purpose of the pipeline, is this a gas pipeline or liquid hydrocarbon pipeline, where the pipeline will be started, where it will be tied-in to, and the length of the pipeline would be.

They would also provide information about the expected flow rate of the fluid (gas or liquid) to be carried per day and usually, they have also conducted the preliminary assessment to identify the pipeline size. Based on the preliminary information provided, then we as a pipeline engineer will start our work, which will be described more in this course.

We can divide the pipeline design activities into two main parts:

1. Pipeline Design: This is the main work in pipeline where the pipeline engineer will design the pipeline. Depend on the stage of the project, whether at Conceptual design, FEED, or Detail Design, but the works will normally consist of the following, as a minimum: preparing the pipeline specification, pipeline wall thickness calculation, pipeline route/corridor drawing, pipeline detail drawings for crossing, branches, valve station, scraper area, tie-in location, plot-plan, pipeline section drawings, schematic diagram, pipe support and anchor detail, hydrotest diagram, and a study about ductile fracture propagation, and at some client also requesting to prepare the material requisition.


2. Flow Assurance Study: this is the analysis which performed to assess the steady state and transient analysis of the proposed pipeline route with main purpose is to determine a preferred pipeline diameter which accommodate the required maximum flowrate between the pressure limitation set by the inlet facility and delivery point. In addition, this analysis is also to assess the potential for surge pressures due to sudden valve closure and pipeline shutdown.

This course will be delivered into several lessons which will cover all activities to be done during Conceptual and FEED stage as well as during detail design.