The Directly Ploughed Concept For Small-Inch Pipelines - A Modern Approach To Reducing Installed Costs And Minimizing Environmental Impact

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Abstract Coiled and straight length metallic pipeline systems, installed by the direct ploughing technique, are in a period of rapidevelopment. These systems (in 33.4 mm through 168.3 mm sizes) are now available in operating pressures of from 690 to 6900 kPa and provide an economic means of delivering large volumes of gas and liquids to processing facilities at low installed costs. This paper will deal with developments in installation (ploughing) techniques for metallic pipeline systems, typical cost reductions available through the use of the technique (vs straight length welding and ditching), plus offer suggestions as to further cost reductions available to operators from the land use/easement purchase and environmental reclamation points of view. Introduction Oil and Gas Production Operations in Canada – Pipelines and Line Pipe Sizes The majority of pipelines installed each year in western Canada for direct production purposes by oil and gas developers are in the 60.3 mm to 168.3 mm range; pipeline expansions in large inch pipe are limited, although some are presently being undertaken to deliver more crude, an increased variety of crude blends, heavy crudes and natural gas to specific end markets(1). Crude oil delivery levels to major pipelines have been kept up in western Canada over the last several years due in great part to high drilling rates (in the late 70s, early 80s and 1985) and increased production from the operating Tar Sands Plants. The large-inch pipelines now in place are being debottlenecked and can handle the steady and declining volumes of rudes being delivered to them. This situation will change in the 90s (when there will need to be more large-inch construction projects to deliver reserves from the frontiers), but until then, pipeline construction in western Canada will likely be concentrated in the "small-inch" area and for the following applications:Delivery of oil and gas to existing and new surface facilities.Transport of oil, gas and NGLs to major pipeline facilities for delivery to end markets.Transport of commodities to enhanced oil recovery schemes (gas, water, solvents).Injection pipelines as part of E.O.R. projects (water, solvents).Water disposal pipelines. In parallel with declining reservoir deliveries and productivity is a natural lowering of operating pressures for the majority of systems. In grid form, the following types of lines can be subjectively classified by their characteristics (operating pressure, burial depth, and corrosivity) and approximate (proportional to the whole) percentages assigned to their sub-categories: Lines by Type of Characteristics (Table 1) Table 1 Available in Full Paper. These Types of Lines do not Need to be Overbuilt! This analysis is very subjective, but the figure as generated for the above lines is probably not far off the mark and these types of lines also have one other characteristic in common – they can be directly ploughed.