The engineering process

Riverlake has vast experience with the management of the engineering process for the development of tank terminals and related infrastructure like underground pipelines or offshore on- and offloading systems. In this article we provide a concise overview of the engineering process for a tank terminal.

Engineering an oil storage terminal is a sizeable and costly effort. To make the engineering process manageable it is typically split in a few steps that need to be aligned with the rest of the development process of the terminal. After each step the design should be formally approved, after which it can be frozen to prevent a going back and forth between steps. 

Functional Requirements 

The process of designing an oil storage terminal starts with defining the functional requirements for the terminal. This is often done by means of a checklist that poses many questions. Such a checklist is to be filled in by the people involved, ideally during interviews with an experienced consultant. Based on an analysis of the information provided, the functional requirements can be determined that typically state the following for a tank terminal: 

— Specifications of the products that will be stored at the terminal 

— Expected flows of these products through the terminal 

— The number and storage capacity of the tanks 

— Required loading and discharging capacities for vessels, trucks, trains etc. 

— Description of the required utilities like electricity, waste water treatment and firefighting. 

Conceptual Design

The next step after defining the functional requirements is to make a conceptual design. Such a design defines in documents and drawings the rough outlines of the terminal and consists at least of the following: 

— A facility description 

— A plot plan or lay-out 

— A Process Flow Diagram (PFD) of the product pipeline systems 

— A description of the utilities 

A conceptual design is used to visually present the project to stakeholders and is the basis for the first capital expenditure (CAPEX) estimations. Making a conceptual design for a terminal is in itself not a big effort, it can be done in a few weeks. In practice it takes often much longer because several versions will be made before all stakeholders agree with the design. Only then the conceptual design can be frozen and the next level of engineering can commence.

Basic Design or FEED

A basic design is based on the conceptual design but much more comprehensive. A number of studies need to be executed by the engineers to size all infrastructure properly. Just to mention a few typical ones: geotechnical surveys, pressure drop calculations, power consumption calculations, sewage capacity calculations and fire safety scenario development. The PFD will be detailed into Process and Instrumentation Diagrams (P&ID’s) for all systems and detailed specifications and lay-outs will be written and drawn for all infrastructure elements. Making a basic design is a major effort. It will take a team of specialized engineers up to half a year, depending on the required level of detail. The basic design is used for one main purpose: to tender it to potential contractors. The basic design is often referred to as Front End Engineering Design (FEED). 

Detailed design and construction engineering

The detailed design and construction engineering of tank terminals is generally done by the construction contractor(s) as part of their preparation for the construction itself. As such, this detailed engineering is also estimated as part of the construction itself. Sometimes people assume that when a contract with a construction contractor is signed, he can start with the construction within a few weeks. Actually the contractor needs a few months to engineer the construction before he can order the required building materials and can start construction on site. 

3D designing 

Nowadays a lot of engineering is done in three dimensions. Tank terminals are most often designed with AutoCAD, the most widely used Computer Aided Design software in the world. With AutoCAD it is relatively easy to add a third visual dimension to 2D designs. Conceptual designs are generally designed in 2D to which the 3rd dimension is added at the end, primarily for presentation purposes. In this way it is possible to present the design rather realistically as if it is photographed from various angles. Real 3D designing is also possible with AutoCAD, but much more time consuming and therefore primarily used for construction engineering where it is important to assure that all parts properly fit together in all dimensions.

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