Page 69 - Impiantistica Italiana 5/2016

Due to the current economic climate Intergraph sister company. Each scan only takes
and low oil prices, the new build mar- about five minutes and captures millions of data
ket is limited as many projects are on points (figure 1). The scanners use time-of-flight
hold, or awaiting Capex funding. By measurement to provide millimeter-precision at a
contrast, upgrading existing plants to range of over 200 meters, depending on the mod-
improve efficiency and extend their el. The equipment is highly portable and can be
life can be attractive given the limited expenditure, moved quickly between scanning stations to cover
availability of infrastructure and trained personnel. the whole plant. The laser’s range means there is
However, the plans and other documentation for no need to get close to hazardous equipment and
older plants are often incomplete or unreliable, and
generally available only in 2D. Fortunately, up-to- Fig. 1 - Within minutes the laser scanner takes millions of
date 3D models can be produced quickly using measurements
laser scanning. Scanning can be done while the
plant is operational, and often without working working at height can be minimized.
at height. It is therefore not only quicker, but also Using the free Leica Truview software the scan data
much safer and less disruptive than the conventio- is presented as a point cloud, in which each pixel
nal plant surveys. has x, y and z coordinates. This means that even
Many process plants include sections that are ol- without building a new 3D model, the point cloud
der than the personnel working in them, and these can be used for measurements and comparisons
sections have often been extended and modified with existing CAD models of the plant (figure 2).
over the years. Consequently, upgrade projects are Together with the photographs, the point cloud
often delayed because the equipment in the field data makes it possible to do a virtual walk-through
does not correspond with the drawings in the ar- of the plant, from one scanning station to another,
chives. As conventional plant surveys are extremely and to take measurements. All this accurate in-
time-consuming and often difficult to undertake in formation greatly helps to reduce risks and avoid
live plants, a better solution is needed. Laser scan- costly mistakes when designing plant upgrades
ning and sophisticated software can help. (figure 3).
I know these issues from both the perspective of
the plant operator and the software vendor. I wor- Case study: creating a point
ked for 12 years at ICI in the UK and was involved cloud at sea
in the design of numerous brownfield and green-
field projects, such as chlorine, pesticide and acid Woodside in Australia is a major owner operator
plants. Out-of-date plant information often led to of floating production storage and offloading ves-
rework or necessitated site visits. At that time, we sels (FPSO). The company purchased an existing
started using photogrammetry to gather as-built
plant information. Later, I moved to a company
specializing in software for these projects. The main
problem was capturing the data, something that is
much easier now that we have laser scanners. At
Intergraph, we have developed advanced software
to convert the point clouds from the laser scanners
into full 3D models. Additionally, the scanners take
detailed photographs so you can basically go on a
site visit of a plant from behind your desk.

Creating a virtual
walkthrough of the plant

The whole process starts with surveying the plant
with a laser scanner from Leica Geosystems, an

Impiantistica Italiana - Settembre-Ottobre 2016 67