Purpose of Pielines
Oil & Natural gas travels from the wellhead to end consumers through a series of pipelines. These pipelines -- including flow-lines, gathering lines, transmission lines, distribution lines, and service lines -- carry Oil & Gas at varying rates of pressure.
The higher the pressure in a pipeline, the more potentially dangerous an accident with that pipeline could be.
NoDoC Cost Database for pipe is used for estimation of following pipelines projects:
Flow-lines connect to a single wellhead in a producing field. Flow-lines move natural gas from the wellhead to nearby storage tanks, transmission compressor stations, or processing plant booster stations. Flow-lines are relatively narrow pipes that carry unodorized raw gas at a pressure of approximately 250 psi (pounds per square inch). Typically, flow-lines are buried four feet underground. Flow-lines can corrode, especially if they are carrying wet gas. Flow-lines are also prone to methane leakage.
2) Gathering Lines
Gathering lines collect oil or gas from multiple flow-lines and move it to centralized points, such as processing facilities, tanks, or marine docks. Gathering lines are medium size steel pipes that carry oil & raw gas at a pressure of approximately 715 psi. Typically, gathering lines are buried four feet underground. Gathering lines carry corrosive content that can affect pipeline integrity within a few years.
3) Transmission Pipelines
Transmission pipelines carry oil & natural gas across long distances and occasionally across interstate boundaries, usually to and from compressors or to a distribution center or storage facility. Transmission lines are large steel pipes (usually 2" to 42" in diameter; most often more than 10" diameter) . They carry oil or unodorized gas at a pressure of approximately 200 to 1,200 psi. Transmission pipelines can fail due to: seam failures, corrosion, materials failure, or defective welding.
4) Distribution Pipelines
Distribution pipelines, also known as "mains," are the middle step between high pressure transmission lines and low pressure service lines. Distribution pipelines operate at an intermediate pressure. Distribution pipelines are small to medium sized pipes (2" to 24" in diameter) and carry odored gas at varying pressure levels, from as little as 0.3 up to 200 psi. Distribution pipelines typically operate below their carrying capacity. Distribution pipelines are made from a variety of materials, including steel, cast iron, plastic, and occasionally copper.
5) Service Pipelines
Service pipelines connect to a meter that delivers natural gas to individual customers. Service pipelines are narrow pipes (usually less than 2" diameter) that carry odored gas at low pressures, such as 6 psi. Service pipelines are typically made from plastic, steel, or copper.
Gathering LinesFeeder LinesTransmission PipelinesDistribution PipelinesTypes of PipelinesThese lines travel short distances gathering products from wells and move then to oil batteries or natural gas processing facilities.Feeder lines move products from batteries, processing facilities and storage tanks in the field to the long-distance haulers of the pipeline industry, the transmission pipelines.Transmission lines are the energy-highways, transporting oil and natural gas within a province and across provincial or international boundaries.Local distribution companies (LDCs) operate natural gas distribution lines.ProductsNatural gas, crude oil and combinations of these products sometimes mixed with water; and natural gas liquids (NGLs) such as ethane, butane and propane.Crude oil, natural gas and NGLs.Natural gas transmission lines typically carry only natural gas and NGLs.Crude oil transmission lines carry different types of liquids including crude oil and refined petroleum products in batches.
Petroleum product lines also move liquids such as refined petroleum products and NGLs.
Natural gas is moved along distribution pipelines to homes, businesses and some industries.DiameterFrom 101.6 mm to 304.8 mm outside diameter (4 in. to 12 in.). Range in size from 101.6 mm to 1,212 mm (4 in to 48 in.) About half are 457.2 mm (18 in.) or larger, and about one third are 254 mm. (10 in.) or smallerMost range in size from 12.7 mm to 152.4 mm outside diameter (half an inch to 6 in.).LengthMore than 250,000 kilometres of these lines are concentrated in the producing provinces of Western Canada, primarily in Alberta.There are more than 25,000 kilometres of feeder pipelines in the producing areas of Western Canada.There are approximately 115,000 kilometres of transmission lines in Canada.There are about 450,000 kilometres of these lines in Canada.
From the initial concept through to the in-service date, designing and building a pipeline is a lengthy process involving many discussions and decisions. Throughout the process, pipeline companies work with various stakeholders to ensure that those directly impacted by the potential pipeline are aware of the project and understand what is involved. The pipeline lifecycle involves many steps, including
Designing pipeline systems requires consideration of a number of factors, including the distance to be traveled, the expected volumes to be received and delivered over the pipeline, and the type and range of products to flow through the pipe.
These factors determine how thick the pipe needs to be built to to ensure safety and how many pumping or compression stations need to keep the energy products flowing smoothly and safely through the pipe.
These physical aspects are just half the design picture. In addition, pipeline designers have to take into account a number of factors when considering the route the pipeline should take. For example:
Regulation and Standards
Regulation of transmission pipelines fall into two basic areas — regulations that help the industry ensure the safety of communities and the environment, and the regulation of transportation charges. In addition, the industry has established or participates in a number of engineering and scientific committees that help set widely accepted technical standards for construction and operation of pipelines.
Public and Environmental SafetyAll aspects of the life cycle of a pipeline — from design and construction to operation and discontinuation (abandonment) — are strictly regulated by a number of regulatory agencies and government departments. These regulatory agencies and government departments ensure Canada’s pipelines are operated safely, responsibly and in the public interest.
Extensive federal and provincial regulation ensures the safe operation of pipelines in Canada. Regulators review CEPA member performance though inspections, audits and incident investigations.
Pipeline systems that cross provincial or international boundaries are regulated by the federal government, primarily under the authority of the National Energy Board. Pipeline operations may also be subject to regulations of other federal, provincial or municipal bodies including Natural Resources Canada, Environment Canada, Fisheries and Oceans Canada, and Transport Canada, depending on the type and ownership of the land which the pipeline crosses. The Transportation Safety Board investigates pipeline incidents and makes recommendations for improvements.
Pipelines which are wholly contained within a province typically fall under that province’s regulatory jurisdiction.
Effective standards are an important element of robust pipeline industry. Regulations surrounding pipelines are based on rigorous standards developed by American Petroleum Institute (API) , ANSI, NACE, ISO, .... In total, there are more than 55 key standards published by different organizations, which cover the design, construction, operation and maintenance of oil and gas pipeline systems and underground storage of petroleum products and liquefied natural gas.
When called on to develop a standard, the organization forms a committee composed of volunteer members. The volunteers are experts selected to represent the various interest groups most likely to be affected by the standard. The organization functions as a neutral third party, providing a structure and a forum for developing the standard.
Click below image to see the specification and list of material that have been considered in NoDoC database for cost estimation.
Types of Pipelines
The Crude Oil Delivery Network
This diagram is illustrative of the Liquids delivery network. Actual delivery network configurations vary.
Moving liquids through pipelines Producing oil fields commonly have a number of small diameter gathering lines that gather crude oil from the wells and move it to central gathering facilities called oil batteries. From here, larger diameter feeder pipelines transport the crude oil to nearby refineries and to long-haul pipelines. The largest pipelines, called transmission lines, transport crude oil and other liquids across the country.
Powerful pumps spaced along the pipeline push the liquid through the pipe at between four and eight kilometers per hour.
Liquid pipelines can be used to move different batches of liquids — on any given day a pipeline could be used to transport different grades or varieties of crude oil — with each batch of liquid is pushed along at the same speed along the pipe. Where the two batches do come in contact with each other there is a small amount of mixing that occurs — these small volumes, known as transmix, are reprocessed
Transmission pipelines transport crude oil to oil refineries — these are the facilities that convert the crude oil into petroleum products through various refining processes. Petroleum products are the useful fuels we use every day. Petroleum products include fuels such as gasoline, aviation fuel, diesel and heating oil, as well as hundreds of products such as solvents and lubricants, as well as raw materials for manufacturing petrochemicals.
Output From a Barrel of Oil (%)
2- Natural Gas Pipelines
Natural gas pipelines are used to transport natural gas from gas wells, to processing plants, to distribution systems throughout Canada. Unlike refined petroleum products, natural gas is delivered directly to homes and businesses through an extensive network of very small diameter distribution pipelines.
The Natural Gas Delivery Network
This diagram is illustrative of the Natural Gas delivery network. Actual delivery network configurations vary.
Operating gas pipelinesIn natural gas producing fields, small-diameter pipes gather the raw natural gas from the producing well and transport it to a gas processing facility, where water, impurities and other gases, such as sulphur are removed. Some gas plants also extract ethane, propane, and butane, which are referred to as natural gas liquids or NGLs. NGLs are then transported via liquid pipelines to oil refineries for processing.
Once cleaned at the gas processing plants, natural gas is compressed prior to moving into large transmission pipelines consisting of steel pipe.
The natural gas flows through the transmission system from areas of high pressure to areas of low pressure through the use of compressors — these are large turbines similar to jet engines, placed along the pipeline to increase the pressure of the gas, “pushing” the natural gas along the pipe to its destination. The compressors often use gas turbines supplied by fuel from the pipeline, but they can also use electricity where preferable.
Once the natural gas reaches its destination, local distribution companies (LDCs) or gas utilities reduce the pressure before the gas continues on for local delivery through smaller distribution network of pipelines.
Pipeline construction is divided into three phases, each with its own activities: pre-construction, construction and post-construction.
Surveying and stakingOnce the pipeline route is finalized crews survey and stake the right-of-way and temporary workspace. Not only will the right-of-way contain the pipeline, it is also where all construction activities occur.
Preparing the right-of-way
The clearly marked right of way is cleared of trees and brush and the top soil is removed and stockpiled for future reclamation. The right-of-way is then leveled and graded to provide access for construction equipment.
Digging the trench
Once the right-of-way is prepared, a trench is dug and the centre line of the trench is surveyed and re-staked. The equipment used to dig the trench varies depending on the type of soil.
Stringing the pipe
Individual lengths of pipe are brought in from stock pile sites and laid out end-to-end along the right-of-way.
Bending and joining the pipe
Individual joints of pipe are bent to fit the terrain using a hydraulic bending machine. Welders join the pipes together using either manual or automated welding technologies. Welding shacks are placed over the joint to prevent the wind from affecting the weld. The welds are then inspected and certified by X-ray or ultrasonic methods.
Coating the pipeline
Coating both inside and outside the pipeline are necessary to prevent it from corroding either from ground water or the product carried in the pipeline. The composition of the internal coating varies with the nature of the product to be transported. The pipes arrive at the construction site pre-coated, however the welded joints must be coated at the site.
Positioning the pipeline
The welded pipeline is lowered into the trench using bulldozers with special cranes called side booms.
Installing valves and fittings
Valves and other fittings are installed after the pipeline is in the trench. The valves are used once the line is operational to shut off or isolate part of the pipeline.
Backfilling the trench
Once the pipeline is in place in the trench the topsoil is replaced in the sequence in which it was removed and the land is re-contoured and re-seeded for restoration.
The pipeline is pressure tested for a minimum of eight hours using nitrogen, air, water or a mixture of water and methanol.
The final step is to reclaim the pipeline right-of-way and remove any temporary facilities.