Part 4.1

Transportation

Objectives

• After reading the chapter and reviewing the materials presented the students will be able to:

• Understand transportation in the early days• Examine ground modes of transport• Analyze marine transportation for oil and gas• Discuss pipeline infrastructure and operations• Explain liquefied natural gas shipping and

offloading

Introduction

• Crude oil was first transported in wooden barrels carried by horse drawn wagons.

• Today tank trucks, rail cars, marine transportation, and gas transmission pipelines have an important role in oil and gas transportation.

• The U.S. federal government partnered with the petroleum industry to construct the first large cross country pipelines for crude oil and refined products (1942).

Gas Transmission Pipelines

• By the beginning of the twentieth century, natural gas was used as fuel in homes and industries.

• Until heavy equipment was invented in the 1920s, construction of pipelines was done largely by manual labor.

• The first large scale natural gas pipelines were the direct result of World War II initiatives.

Ships at Sea

• Transporting oil in large bulk tanks did not immediately replace barrels, because oil moving in a tank could throw a ship off balance.

• New designs stored oil in separate steel compartments with pipes for loading, unloading, and venting gas accumulations.

• Diesel engines replaced steam engines as an improved power source for ships.

Tank Trucks

• During World War I welding replaced riveting as a means of fabricating the tanks.

• During and after World War II, liquefied petroleum gas (LPG) became a major commodity for tank truck transportation.

• Today tank trucks are mainly used in distributing refined products from product terminals to service stations and other outlets.

Railway Systems

• Railways systems transport crude oil and other feedstocks to refineries, refined products to demand centers, and petrochemicals between plants and to customers.

• Separate railroads share railway tracks by agreement.

• Railroads own and maintain their infrastructure.

Petroleum Products Transported by Rail

• The chemical industry relies heavily on rail tank cars to transport millions of gallons of petrochemicals used in various manufacturing processes.

• Many chemicals are shipped from refineries to chemical plants to manufacturing centers for conversion into plastics, synthetic fibers, paints, and other products.

• Ethanol must be moved by rail because it can cause stress corrosion cracking in pipe which damages the sealing materials used in pipelines.

• Because most petroleum derivatives are considered hazardous materials, the Federal Railroad Administration (FRA) of the U.S. Department of Transportation controls their transport within the United States.

Tank Car Design and Manufacture

• Special tank linings and insulation along with metals unaffected by corrosive liquids are required for specific products transported.

• A general purpose car carries 20,000 to 33,000 gallons or more of liquid.

• Tank cars are regularly inspected and monitored by the rail company.

• The TankTrain consists of interconnected cars that can be loaded or unloaded through a single connection. A large flexible hose connects each tank car to the one in front of it.

Motor Transportation

• Trucking companies own, lease, operate, maintain, and staff the motor carrier industry.

• Motor carriers provide flexibility because they can respond to short lead times and can reach numerous locations not practical using other modes of transportation.

• A typical motor carrier can haul about 9,000 gallons of gasoline and 7,500 gallons of diesel fuel due to weight restrictions of typically 80,000 pounds.

• Many tank trailers have separate compartments within the tank that allow several products to be hauled in one truck.

Crude Oil Trucks

• Crude oil trucks are especially useful in new oilfields where pipelines cannot be initially justified.

• The crude oil is usually hauled to a nearby pipeline gathering station or directly to a refinery.

Liquefied Petroleum Gas Transport

• Some products require refrigerated pressure tanks.

• The products are kept liquefied with insulation or cooling equipment.

• LPG can also be dispensed to trucks from remote storage locations supplied by pipeline.

• Computers and special meters measure and monitor product flow and volume, print bills of lading, and provide security system to ensure safe operations.

Government Regulation

• In the United States, regulations vary state by state concerning the operations of motor vehicles carrying petroleum and petroleum products.

• Driver training qualifications, driving rules, licensing equipment and accessories, accident reporting, maintenance requirements, and vehicle weight and sizes are governed.

• The Surface Transportation Board, an autonomous entity within the U.S. DOT (Department of Transportation), oversees regulations at the federal level.

Barges

• Petroleum and petroleum products are transported by barge whenever there is a waterway and a need for the products.

• Barges carry gasoline, asphalt, crude oil, chemicals, and industrial fuel.

• Barges usually have no power to move on their own. They depend on tugboats, towboats, and water currents to move.

Tugboats and Towboats• Tugboats are powered vessels designed to push or pull other vessels in harbors, or

inland waterways.• Unlike a tugboat, a towboat is a relatively flat bottomed boat with a square front.• Towboats, like tugboats have a large engine capable of pushing a string of barges

carrying thousands of barrels of petroleum products over great distances at low cost.• The towboat crew typically consists of a captain, a ship’s mate, a chief engineer, an

assistant engineer, a tankerman, a pilot, a cook, and deckhands.• The crew builds the tow by hooking a number of barges together.• All personnel, from the captain to the deckhands and attendants on the docks, who

work on U.S. waterway vessels must be trained and certified under U.S. Coast Guard rules and regulations.

• Fuel and supplies are furnished by service boats that come alongside the tow in midstream.

Oceangoing Tankers

• After World War II, oceangoing tankers became the major mode of transporting oil.

• Crude oil tankers vary in size from smaller tankers of 20,000 tons to huge carriers with capacities exceeding 500,000 tons.

• Besides crude oil, oceangoing vessels also transport refined products, natural gas liquid (NGL), and liquefied natural gas (LNG).

• Modern tankers transport nearly two-thirds of the petroleum produced in the world.

Supertankers

• As larger refineries were built, larger vessels were needed to move petroleum products more economically.

• A single supertanker carrying 2 million barrels can transport enough petroleum to heat homes and power the cars of a city of 85,000 people.

• Today smaller tankers have largely replaced the global fleet of supertankers once deployed worldwide.

Average Size Tankers

• The use of smaller tankers has grown due to the following:• Construction of new pipelines.• Flexibility and lower cost of smaller tankers.• Increased transport of refined products worldwide.• Discovery of new oilfields that eliminated the necessity of many long

hauls.• Canals and waterways can accommodate average size tankers.• Icebreaking Tankers: In the arctic ocean, Baltic Sea, and other ice-

laden seas, icebreaking tankers are needed. These tankers can charge higher rates.

Natural Gas Tankers

• Natural gas is liquefied before it is transported.• The LNG is regasified when it reaches its

destination.• If separated before shipment, butane, propane,

and ethane (referred to as LPGs) must be transported in tankers designed to handle the high pressures and low temperatures needed to keep these hydrocarbons in a liquid state.

• As the gas liquefies it shrinks to 1/600th of its original volume.

Loading and Offloading Facilities

• Because few ports are large enough to accommodate supertankers, oil ports of entry use methods of loading and offloading at sea.

• Most world ports have offshore mooring facilities and underwater pipelines that transfer oil from shore to ship, ship to ship, or ship to barge.

Crude Oil Pipelines

• Pipelines devoted to the transportation of petroleum liquids have increased from 124,000 miles postwar to more than 200,000 miles today.

• Total quantities shipped have steadily increased because of larger diameter lines and laying additional lines alongside existing pipelines (looping).

Field Gathering Systems

• Various tanks and treating vessels are often a part of the field gathering system.

• Gathering system operations are typically unmanned or lightly manned.

• Personnel monitor and adjust the precision measurement devices and pumping equipment in the gathering system.

• Maintenance involving mechanical and electrical equipment is usually done by maintenance technicians.

Pump Station Operations

• Pumps at pump stations located along the pipeline move oil into and through the pipeline.

• A gathering station is in or near the oilfield and receives oil through a pipeline gathering system, usually from the producer’s tanks.

• From the gathering station, oil is moved to a trunkline station located on the mainline or trunkline.

• The trunkline station relays oil to the refineries or shipping terminals.• Booster pump stations are spaced along the trunkline to add

pressure so that the oil will continue to move along the pipeline.• Tank farms along the line serve as receiving, separating, and

holding locations.

Gathering & Trunkline Stations

• At gathering stations, the oil changes custody from the producer to the pipeline company.

• The gathering station may include one or more pumps that move oil from various producer’s tanks.

• After the oil is received at the gathering station, it is pumped to a trunkline station.

• A trunkline or mainline station is located on a main petroleum carrying artery.

• Today, pumps used in trunkline stations are typically high speed centrifugal units driven by large electric motors.

Station Tank Farms & Manifolds

• A tank farm is a place where oil in transit can be temporarily stored for separation, measurement, and rerouting.

• The pipeline company can make controlled deliveries to various shippers at refineries or terminals at desired pumping rates.

• A manifold is an auxiliary system of piping that separates the flow into several paths, combines several flow paths into one, or reroutes the flow to any one of several possible destinations.

Control of Oil Movements

• The coordination of shipments for liquid petroleum, whether for crude oil or refined products, is a critical function.

• After receiving the shipper’s tender information, a scheduler uses computerized scheduling tools to lay out the next month’s pumping sequences and compiles a schedule to meet next month’s pumping sequences and compiles a schedule to meet each shipper’s needs.

• This schedule (or pumping order) is given to controllers at the pipeline’s control center to implement in the upcoming month. This information is also sent to any connecting carriers, manned receipt and delivery terminals, and shippers.

• Today, pipeline controllers handle pipeline operation by remote control using supervisory control and data acquisition (SCADA) system.

• The controllers continuously monitor hydraulic, electrical, mechanical, and other control parameters and control movements by issuing commands to operate valves of manifolds, start-stop pumps, and other equipment.

Measurement, Quality Assurance, & Oil Accounting

• Liquid petroleum pipelines have support services to assure accurate measurement and tight quality control.

• These support services train personnel and monitor methods and equipment used by field personnel to measure, sample, and analyze oil moving through the pipeline.

• The basic accounting document used for buying, selling, and taking custody of crude oil is the run ticket.

• Each time custody of oil changes hands, a run ticket is generated showing precise measurements of the quantity and quality of the commodity.

• The ticket is usually signed and witnessed by the entity receiving the oil and the one delivering the oil.

Products Pipelines

• A products pipeline transports refined products derived from crude oil, such as gasoline, diesel fuel, kerosene, jet fuel, heating oil, and other liquid hydrocarbons.

• Product pipelines usually start at or near refineries and end at terminals in areas of high market demand for the products.

• In the United States there are approximately 95,000 miles of product pipelines.

Control of Product Movement

• The process begins with shipper’s tender nomination for the upcoming month, usually done around the middle of the preceding month.

• The process identifies volumes of each type of product, their origins, their destinations, and other information.

• A schedule is developed that lists the volumes and movement sequences, or batches over the upcoming month by cycle.

• Like crude oil pipelines, the schedule is sent to controllers at pipeline control centers for implementation.

• The information is also sent to shippers, refineries, manned terminals, and interconnecting pipelines.

• Breakout tanks located at the origin, intermediate, and destination locations are tanks that hold petroleum liquids until they can be delivered or relayed to local shipper’s tanks or product terminals further up the pipeline.

Batching

• Batching is the pumping of different crude oil or refined products in a sequence on the same line.

• Crude oil and refined products are rarely moved on the same pipeline.

• As long as the pipeline flow and pressure remain high and the line is packed, the mixing or interfaces between batches is relatively small, compared to the very large batches on either side of it.

• This slight mixing, called transmix, is put into a tank when the batches are delivered for later disposition.

Regulatory Environment

• Safety and environmental protection regulations that cover design, construction, operations, and maintenance are administered under the U.S. DOT (Department of Transportation) through its Pipeline and Hazardous materials Safety Administration (PHMSA) office.

• The pipeline industry must adhere to strict regulations regarding these aspects of business: financial, safety (OSHA), environmental (EPA), and placement.

• State and local governments present further restrictions and challenges for pipelines through additional regulatory requirements and project permit provisions.

Natural Gas Pipelines

• Historically, gas pipelines and oil pipelines have been managed and operated by different companies.

• A gas pipeline uses pressure from compressors as its driving force.

• An oil pipeline uses pump pressure.• Gas pipelines move their volumes in a

gaseous state as opposed to liquid state in the oil pipelines.

Modern Transmission Systems

• Of the more than 1.8 million miles of U.S. gas pipelines in use today, about 278,000 miles are natural gas transmission trunk lines while the remaining are gathering and distribution lines.

• Due to the vast network within most cities and towns, the distribution lines account for the majority of the 1.8 million pipeline miles.

• Gas gathering systems have specialized equipment for conditioning the gas so it will flow safely and steadily; controlling, measuring, and recording its flow through the pipeline; and ensuring gas quality specifications are met.

Conditioning and Compressors

• Conditioning equipment includes processing equipment such as separators, heaters, and dehydrators located at the wellhead or at other locations in the field.

• The equipment removes water, NGLs, LPGs, and undesirable components such as nitrogen and oxygen, leaving a relatively clean commodity – methane.

• In addition large compressors compress the gas to the required discharge pressure.

Automation

• As with liquid systems, gas pipelines are automated with a SCADA computer system that monitors, controls, and coordinates operation of the pipelines, valves, prime movers, and conditioning equipment.

• A computer receives transmitted input from each part of the system.

• Appropriate alarms will be actuated depending on any malfunction or anomaly, and the system will generate logs for recordkeeping or regulatory purposes.

Odorants

• Natural gas is typically odorless.

• A chemical odorant called a mercaptan is added to natural gas to give it a distinctive pungent odor so people can smell it in the event of a leak.

• By adding an odorant, it is possible to detect leaks or other unburned gas discharges before hazards develop.

Pipeline Construction on Land

• The oil company’s transportation department determines how long and what size pipeline will meet the needs.

• Estimates of capital costs and operating expenses are made and long term rate of return is calculated.

• Once management approves the project, design engineering determines routing, pipe design and coating, design of components, power and control systems, and ancillary equipment.

• Governmental approval is a lengthy process involving environmental studies and permits.

• After the permits are obtained, and right of way is procured, a construction contract is secured and the work begins.

Assembling the Spread

• A spread is a stand alone project that includes the manpower, equipment, and material needed to build a pipeline.

• A spread for an average project might have 200 to 300 workers and for a very large project up to about 500 workers.

• The time and progress of the construction project depends on the pipe size and the construction environment (streams, marshes, forests, etc).

• The task performed by a typical spread includes clearing, grading the right of way, ditching, stringing, bending, welding, lowering in, backfilling, tie-ins, testing, cleanup, and comisioning.

Clearing Right of Way

• After the right of way is procured, clearing operations begins.

• The construction right of way usually involves a strip of land about 50 to 100 feet wide, depending on the pipe size and terrain.

• The crew typically uses bulldozers to remove boulders, brush, and other impediments that could interfere with construction.

• A wheel ditcher is commonly used to dig the ditch to bury the pipe.• The ditch must be at least 12 inches wider than the pipe diameter.

The U.S. DOT regulations require a minimum of 30 inches depth of cover across farmland in normal soil and 36 inches in municipal areas.

• Stringing is the process of delivering and distributing pipeline along the right of way. The pipe is cleaned, primed, and coated with corrosion protection before delivery. Coated pipe requires special handling to prevent damage to the coating. Special pipe bends called hot bends are premanufactured and shipped to the spread.

Aligning & Welding Pipe

• Before pipe is positioned for welding by the pipe gang, the pipe ends are cleaned and bevels are checked for damage.

• Line-up clamps are used to align the pipe ends before welding.

• Pipe welding is a tightly specified and controlled process to make the welds stronger than the pipe itself.

• The welds are inspected visually by company inspectors and with nondestructive testing (NDT) usually by x-ray.

• Any defective welds are cut out or repaired.

Coating and Wrapping Pipe

• Steel pipes corrode when placed in the ground.• Three types of common pipe coatings are:• Fusion-bonded epoxy coatings are usually applied at the pipe

manufacturing or coating plant• Enamel coatings can be applied to pipe while it is being laid. Coal

tar enamels are particularly effective. The enamel coated pipe is then wrapped with fiberglass, reinforced felt, and Kraft paper.

• Over the ditch tape uses a machine to clean, prime, coat, and wrap the pipe. The taping machine with rolls of tape (polyethylene, polyvinyl, or other materials) mounted on spindles wraps the tape in overlapping sections around the pipe as it moves along the line.

Lowering in and Backfilling

• After the pipe has been lowered into the ditch, the crew replaces the soil in the ditch covering the pipe.

• Backfilling involves breaking up rocky soil before it is returned to the ditch.

• Uneven distribution of backfilled soil can leave sections of pipeline unsupported and cause damage.

Specialty and Tie-In Crews

• Any sections of pipeline requiring special construction techniques and equipment are bypassed.

• Breaks or bypassed sections are usually crossings at highways, railroads, waterways, swamps, and marshes.

• Specialty or tie-in crews complete unfinished sections and connect them to the rest of the pipeline.

Cleanup and Restoration

• As construction progresses and backfill is completed, cleanup and restoration work follows.

• The land surface is restored as nearly as possible to its original condition.

• The right of way is left free of trees and brush to allow required visual inspection, usually by aircraft, after the pipeline is placed in operation.

Testing and Commissioning

• Internal pipeline cleaning is usually done with an air driven swab.

• The pipeline is tested by filling with water or other test medium and pressure testing the finished line to assure it meets regulatory and design requirements.

• The construction contractor transfers the pipeline to the owners who in turn commission it ready for operation.

Offshore Pipeline Construction

• Modern technology has made it possible to lay pipelines in much deeper areas of the sea.

• Various types of pipe laying barges are used in offshore pipeline construction.

• The pipeline industry has also developed advanced techniques for offshore pipeline operations in ice laden arctic waters.

Conventional Lay Barges

• A lay barge allows the pipeline to be assembled and laid continuously along the route, either on top of the ocean floor or in trenches on the seafloor.

• Support vessels supply these barges with pipe and construction materials as well as moving personnel and supplies they will need while on board.

• The completed pipeline is lowered into the water by way of an inclined ramp.

• Offshore pipeline is precoated with a high density cement to overcome buoyancy, allowing it to sink into place.

Bury Barges

• Subsea pipelines that might be harmed by fishing or other marine operations are laid in a seafloor trench.

• On softer sea floors a bury barge or pipe trenching barge with a sled is used for this operation.

• The sled uses high pressure jetting action to form a trench into which the pipeline will rest.

• The movement of seawater eventually covers the pipeline.

Other barges

• Super barges are designed for use in rough seas and deep water. This barge can lay 80 foot long double jointed pipe in deep water. The super barge can accommodate up to 350 people.

• Semisubmersible barges are designed to minimize the effects of wave and wind action when operating in extremely rough waters. They can lay pipe in the North Sea during 75 foot waves and 70 mile per hour winds.

• Reel Vessel: Pipe is welded together and spooled onto giant reels at onshore facilities and then loaded onto a reel vessel. It is unwound by simply moving the barge forward.

Economics and Safety

• Economic and safety factors generally determine which method of transportation will be used to ship crude oil, petroleum products, and natural gas.

• The four modes of transportation used to move petroleum are pipelines, water carriers, motor carriers, and railroads.

• Pipelines are the safest and also the most economical mode of transporting oil and products as long as throughput remains relatively high.

Liquefied Natural Gas (LNG)

• Transporting natural gas in large quantities is done mostly by pipeline.

• Large oceangoing ships can transport LNG over long distances.• A LNG project consists of the following components: gas

production, pipeline transmission, liquefaction, shipping, regasification, and sending out to the local pipeline grid.

• The liquefaction plant is the most expensive link in the LNG monetary chain.

• The LNG receiving terminal is the essential link between LNG ships and the pipeline grid.

• In the United States DOT regulates the transportation of LNG.

Summary• Ethanol must be moved by rail because it can cause stress corrosion cracking in pipe which damages the sealing materials used in

pipelines.• A typical motor carrier can haul about 9,000 gallons of gasoline and 7,500 gallons of diesel fuel due to weight restrictions of typically

80,000 pounds.• Modern tankers transport nearly two-thirds of the petroleum produced in the world.• Pumps at pump stations located along the pipeline move oil into and through the pipeline.• A gathering station is in or near the oilfield and receives oil through a pipeline gathering system, usually from the producer’s tanks.• From the gathering station, oil is moved to a trunkline station located on the mainline or trunkline.• The trunkline station relays oil to the refineries or shipping terminals.• Booster pump stations are spaced along the trunkline to add pressure so that the oil will continue to move along the pipeline.• Tank farms along the line serve as receiving, separating, and holding locations.• The basic accounting document used for buying, selling, and taking custody of crude oil is the run ticket.• A products pipeline transports refined products derived from crude oil, such as gasoline, diesel fuel, kerosene, jet fuel, heating oil, and

other liquid hydrocarbons.• Breakout tanks located at the origin, intermediate, and destination locations are tanks that hold petroleum liquids until they can be

delivered or relayed to local shipper’s tanks or product terminals further up the pipeline.• Batching is the pumping of different crude oil or refined products in a sequence on the same line.• Conditioning equipment includes processing equipment such as separators, heaters, and dehydrators located at the wellhead or at

other locations in the field.• A chemical odorant called a mercaptan is added to natural gas to give it a distinctive pungent odor so people can smell it in the event of

a leak.• A spread is a stand alone project that includes the manpower, equipment, and material needed to build a pipeline.• The welds are inspected visually by company inspectors and with nondestructive testing (NDT) usually by x-ray.• Subsea pipelines that might be harmed by fishing or other marine operations are laid in a seafloor trench.• A LNG project consists of the following components: gas production, pipeline transmission, liquefaction, shipping, regasification, and

sending out to the local pipeline grid.

Home Work

• 1. Why does ethanol have to be moved by rail and not by pipelines?

• 2. What is a run ticket?• 3. What is batching?• 4. How are pipeline welds tested?