Lower costs, environmental protection drive future pipeline technologies.

Constructing oil and gas pipelines onshore and offshore in the 21st Century will reflect efforts well underway at the end of the 20th Century: developing more cost-effective technologies but also mitigating environmental impact during construction and operation. These efforts will improve public acceptance of such projects.

This discussion follows the path that implementation of a typical pipeline project normally follows, from route selection via basic and detail engineering through to construction, operation, and maintenance of the system.

Onshire

Route engineering

Great advances in surveying and mapping have been evident in route engineering in recent decades. But such development has also been characterized by a fundamental change in selecting the optimum route, which had been based formerly on technical and economic considerations.

Today-and especially in the coming decades--it is necessary to find a route which is technically feasible, is constructible at reasonable costs, causes minimum damage to the environment, and creates minimum resistance from the public, and for which the necessary right-of-way can be acquired without delays.

These changes in approach for route selection and in definition of the "optimum route" are not restricted to urban, industrialized regions, but also apply to developing countries.

Although technical aspects of the general route are still studied with existing maps, there is a strong preference for use of satellite images.

For detailed route investigation, it is state of the art to take advantage of the progress made in aerial survey. Orthographic photos from this survey in combination with contour lines make possible in-depth route studies without field work. Only as a last step is the route verified in the field.

Aerial photos or videos also help define the environmental status as part of an impact assessment and give opportunities for fast and cost effective mapping of the topographical and environmental situation.

Depending on the grade of required detail, accuracy can be adjusted by the height of the GPS-controlled flight for the photo shooting and the implementation of conventional surveyed data for special points (GPS = global positioning system). Figs. 1 and 2 offer examples.

The future lies in satellite-based surveys, but as yet the accuracy of publicly available data is insufficient for detailed engineering. Resolutions of satellite imaging are constantly improving, however.

Modern information technology in the form of geographic information systems (GIS) has revolutionized pipeline mapping. The layers of topographic, environmental, pipeline, and ROW-related data can be combined in various ways to produce all necessary maps and alignment sheets.

Modern GIS technology facilitates not only production of the route drawings, but also any revisions due to relocations to find the optimum route as defined above.

Still unsolved is the search for a similar, cost-effective method for conducting soil surveys. Research and development concentrate on infrared- or radar-based surveys, but the relevant data still are limited to the upper zones. Development of seismic surveys for this specific purpose might be a feasible solution.

Pipeline design

Driven by the desire to minimize investment for pipelines, efforts are being made to increase operating pressures in combination with development of higher steel grades and to reconsider installed spare capacity in pumping and compressor stations. A typical example of this trend is the Alliance Pipeline with 120-bar (1,740-psi) operating pressure and single unit design. [1]

Operating costs have been reduced by considerably improving the thermal efficiency of gas-turbine drives especially for gas pipelines and installation of high-efficiency pumps combined with variable-speed drives for crude oil and product pipelines.

Application of modern information technology has revolutionized monitoring and control of pipeline systems. Modern hard- and software that runs pipelines online or assists the operator off-line aims at safe and cost effective operation.

Fiber optic cable laid along …