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Gas Pipeline Maintenance and Safety

       The main goal of a natural gas distribution company is to deliver affordable energy to customers in a safe manner at the lowest possible cost.  Utility companies in the United States are private businesses, even though they are regulated by local, state, and federal agencies, and must make a reasonable profit in order to pay employees, finance support services, expand services, and keep the natural gas distribution system well-maintained and safe (Busby, 1997, p. 45).

       Before a pipeline is even built, it must be approved by the Federal Energy Regulatory Commission (FERC).  Companies must submit their “construction plans and economic studies that demonstrate a demand for gas in the area to be served and an available, adequate supply of gas” (Busby, 1997, p. 45).  Companies must also detail the pipeline’s environmental impact on the local surroundings.  Once the FERC approves the pipeline, it issues a certificate to the company (Busby, 1997, p. 44-45).

       The next steps are to purchase the right-of-way and lease property along the path of the pipeline.  Peculiarities in the local environment, the length of the pipeline, the local population, expected customer needs, and the projected load dictate what choices the design engineers make – gas pressure, pipe diameter, pipe wall thickness, type and spacing of compressors, and more. Computer software now exists to assist engineers to choose the right location and calculate the right specifications.  Once all this is done, the appropriate pipes, valves, and other parts and equipment are ordered (Busby, 1997, p. 45).

       Ditching machines dig deep trenches in the ground, and sections of pipe are laid out along the trench.  The sections of pipe are held in place while welders weld the lengths of steel pipe into one long pipeline.  After the pieces of pipe are welded, “the outside surface of the pipe is cleaned, coated, and wrapped to inhibit external corrosion” (Busby, 1997, p. 46).  Frequently, these pipes have been coated inside at the steel mill to prevent corrosion; to aid internal inspection of the pipe; to reduce water retention after hydrostatic testing; to reduce absorption of gas odorants; to create a friction-free surface.  After the pipe is welded, coated, and inspected, it is lowered into the trench, where it is re-covered with appropriate backfill (Busby, 1997, p. 46-47). 

       At any point along this timeline, safety issues can come up which might not become apparent until months or years later.  A faulty pipe, an inappropriate valve, a design flaw, a pipeline that is allowed to carry too much pressure, an improper weld or inappropriate backfill, may lead to a dangerous break or leak later on down the line.

       Safety is the paramount concern in pipeline operations.  “Pipelines require regular patrol, inspection, and maintenance, including internal cleaning and checking for signs of gas leaks” (Busby, 1997, p. 51-52).  A major pipeline disaster could lead to political and economic repercussions, as well as environmental pollution and threats to property and human lives (Busby, 1997, p. 51-52).

       The most common cause of pipeline damage is third-party damage, caused by contractors and other people digging too close to natural gas lines.  Any damage to the pipe, the coating, or the welded joints can cause leakage and breakage.  Most states now have requirements for contractors to determine the location of utility lines before they dig new trenches (Busby, 1997, p. 52).

       Corrosion is the second most common cause of pipeline damage. “To minimize corrosion, pipeline companies install electrical devices called cathodic protection systems, which inhibit electrochemical reactions between the pipe and surrounding materials” (Busby, 1997, p. 52).  Any kind of rust, cracking, or pitting can cause pipe breakage or leakage.  If the original coating on the pipe was defective before use, the problem may go undetected for a long time (Busby, 1997, p. 52).

       A hydrostatic test can prove whether or not a pipeline is defective or needs repairs.  The gas is removed from the pipeline and the pipe is filled with high-pressure water.  But this is an expensive procedure so pipeline operators use a device called a pig that travels through the pipeline to remove dirt and corrosion.  These materials can cause damage to the pipes, regulators, and meters.  More advanced pigs (smart pigs) use technology that can measure pipe wall thickness and other abnormalities which can indicate corrosion and other damage (Busby, 1997, p. 52-53).

       Aerial patrols of transmission lines make routine surveys that can detect signs of leakage, such as patches of yellow vegetation in areas that are normally green; construction projects that may have damaged the line; or bare pipes that need to be re-covered (Busby, 1997, p. 53).

       Leak detectors can detect gas leaks above and below the ground.  Workers can detect leaks by the presence of brown or yellow vegetation.  By digging small holes at these locations, gas leaks can be detected by visual inspection or the odor of gas.  Inline cameras are used to detect leaks inside pipelines (Busby, 1997, p. 67).

       Workers routinely survey pipelines for leaks on a set schedule.  Public buildings, such as schools, hospitals, government offices, and theaters, are given priority attention.  Serious leaks are repaired immediately.  Companies are obligated to investigate customer reports of gas odor, leaks, explosion, or fire in a reasonable amount of time, according to the severity of the leak (Busby, 1997, p. 67).  Natural gas utilities post information on their websites educating consumers on detecting and reporting natural gas leaks.

       Mains and other distribution pipes made of plastic are repaired by shutting off the gas and squeezing closed the pipe on each side of the leak.  The leaking section is replaced with new pre-tested plastic piping and appropriate connections made on each end. “Mechanical couplings are commonly used for this purpose” (U.S. Department of Transportation, 2017, p. VI-20).  Repairs must be done by qualified technicians (Busby, 1997, p. 69). 

       Leaks in steel pipes can be repaired with “leak clamp[s] applied directly over the leak” (U.S. Department of Transportation, 2017, p. VI-20).  If multiple leaks are found, the easiest way to repair the pipe is to replace it altogether with pre-tested pipe that has been coated, wrapped, and strengthened by cathodic protection.  Steel pipe can also “be replaced by inserting PE pipe manufactured according to ASTM D2513 in the existing line and making the appropriate connections at both ends” (U.S. Department of Transportation, 2017, p. VI-20).  Qualified technicians must be used to make the repairs who will use the proper connections, provide adequate support, and consider thermal expansion and contraction of the PE pipe (U.S. Department of Transportation, 2017, p. VI-20).

       Instead of repairing cast iron natural gas pipes, the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) instituted programs to identify, manage, and replace cast and wrought iron pipelines as early as 2009.  The Distribution Integrity Management Programs (DIMP) became mandatory for all U.S. pipeline operators in 2011 (U.S. Department of Transportation, 2020).

       In 2012, PHMSA urged state pipeline safety agencies to “monitor cast iron replacement programs, establish accelerated leak surveys, focus safety efforts on high-risk pipe, incentivize pipeline rehabilitation, repair and replacement programs, strengthen inspection, accident investigation, and enforcement actions, and install home methane gas alarms” (U.S. Department of Transportation, 2020).  While cast iron gas pipes can be repaired using PE or steel pipe and the appropriate connections by qualified technicians, the official recommendation is to replace these pipes altogether.

       The United States Department of Labor’s Occupational Safety and Health Administration (OSHA) is restricted by Section 4(b)(1) of the Occupational Safety and Health Act when it comes to oversight of oil and gas pipelines.  OSHA’s authority is largely limited to contractors hired by pipeline owners and operators and their workers when it comes to occupational health and safety hazards (United States Department of Labor, 2004).

       The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) is the primary regulator of oil and gas pipelines in the United States.  The administration sponsors a Gas Distribution Integrity Management Program which requires all operators to create a Distribution Integrity Management Program (DIMP) that includes the following elements: “knowledge; identify threats; evaluate and rank risks; identify and implement measures to address risks; measure performance, monitor results, and evaluate effectiveness; periodically evaluate and improve program; report results” (U.S. Department of Transportation, 2020).

       Gas distribution systems are a necessary part of modern life.  With all stakeholders working together to achieve optimal safety, natural gas will continue to be a safe, low-cost, efficient form of energy.


Busby, R.L. (Ed.). (1999). Natural Gas in Nontechnical Language. Tulsa, OK: PennWell.

U.S. Department of Transportation. (2017). Guidance Manual for Operators of Small Natural

       Gas Systems. Oklahoma City, OK: U.S. Department of Transportation.

U.S. Department of Transportation. (2020). Pipeline replacement. Retrieved from


U.S. Department of Transportation. (2020). Gas distribution integrity management. Retrieved

       From https://www.phmsa.dot.gov/technical-resources/pipeline/gas-distribution-integrity-


U.S. Department of Labor. (2004). Laws and regulations. Retrieved from


Dawn Pisturino

Thomas Edison State University

December 8, 2020; April 19, 2022

Copyright 2020-2022 Dawn Pisturino. All Rights Reserved.


History of Chevron Corporation

(Standard Oil Company of California gas station)

       In September 1876, oil driller Alex Mentry struck oil at Pico No. 4 in Pico Canyon, California.  This set off a new “gold rush” in search of oil, the “black gold.”  At the time, Mentry worked for California Star Oil.  A few years later, on September 10, 1879, Pacific Coast Oil Company, which had incorporated in San Francisco, California on February 19, 1879, acquired California Star Oil – and this is where the history of Chevron begins (Chevron, 2020).

       Pacific Coast built the largest refinery in California at Point Alameda on San Francisco Bay, with the capacity to produce 600 barrels a day.  The company built a pipeline from Pico Canyon to the Southern Pacific Railroad train station at Elayon in southern California. By 1895, they had acquired the first steel tanker in California, the George Loomis, which could hold 6,500 barrels of crude oil (Chevron, 2020).

       In 1878, competition appeared in the form of Standard Oil Company (Iowa).  Known for its marketing skills, quality products, effective advertising campaigns, and rich financial backing, it set up shop in San Francisco, California with the goal of dominating the West Coast’s oil market.  By 1885, Standard Oil had distribution centers throughout the West Coast.  By contrast, Pacific Coast Oil Company was struggling to survive. Finally, in 1900, Standard Oil purchased the struggling company in order to increase its own production, transportation, and refining operations. In 1906, consolidation between Pacific Coast Oil and Standard Oil (Iowa) produced a new company – Standard Oil of California (Chevron, 2020).

       In 1911, Standard Oil of California established the California Natural Gas Company at its El Segundo plant in southern California in order to explore for natural gas in the San Joaquin Valley.  A second pipeline was built, linking the Richmond refinery, which was built in 1902, and the Kern River Field (Chevron, 2020).

       In an effort to conserve energy resources, the Starke gas trap – invented by engineer C.C. Scharpenberg and geologist Eric Starke — was invented and implemented for capturing natural gas from a well (Chevron, 2020).

       Between 1912 and 1919, Standard Oil of California expanded its operations until it saturated the market in a five-state area.  “Petroleum and natural gas are by far the major fuels used on the Pacific Coast” (Miller, 1936, p. 86).  But its market share had dropped by 1926 due to increased competition.  With the re-opening of the Panama Canal in 1914, Standard Oil of California ventured into the international market and expanded its market share in the Eastern United States and Europe (Chevron, 2020).  Natural gas use, however, continued to grow, from 72,000 cubic feet consumed on the West Coast in 1921 to 258,000 cubic feet consumed in 1933 (Miller, 1936, p. 86).

       Standard Oil of California continued to expand its operations through subsidiaries, mergers, and partnerships.  It opened operations in the Middle East, Canada, Mexico, and Central America.  In September 1950, the company completed the Trans-Arabian Pipeline.  Company revenues reached 1 billion dollars in 1951.  A merger with Standard Oil of Kentucky in 1961 expanded its markets in five southeastern states.  In 1977, Chevron USA was formed with the merger of six domestic oil and gas operations.  In 1979, Chevron celebrated 100 years of operations (Chevron, 2020).

       In March 1984, Chevron merged with Gulf Oil Corporation.  This merger increased their reserves of oil, gas, and natural gas liquids.  In the 1990s, Chevron developed the Escruvos

Natural Gas project in Nigeria, converting natural gas to liquids.  In 1996, “Chevron transferred its natural gas gathering, operating, and marketing operation to NGC Corporation (later Dynergy) in exchange for a roughly 25% equity stake in NGC” (Chevron, 2020). Through its merger with Texaco, Chevron acquired 11 million oil-equivalents of natural gas reserves.  Using 3-D imaging signals, Chevron discovered one of the largest crude oil and natural gas fields in the U.S. Gulf of Mexico in May 2009.  In 2005, Chevron changed its name to Chevron Corporation, acquired Unocal, and increased its natural gas reserves by 15 per cent.  The Gorgon Project and Wheatstone Project in Western Australia are boosting Chevron’s liquefied natural gas reserves. Gorgon, which will supply the Asia-Pacific market, had a daily production of 2.3 billion cubic feet of natural gas and 6,000 barrels of condensate in 2019.  Production is projected to last 40 or more years, with 15.6 million metric tons of liquefied natural gas produced per year (Chevron, 2020).

       “Chevron’s development of oil and natural gas from shale and tight rock formations has intensified since the company entered the Marcellus Shale through its acquisition of Atlas Energy in 2011” (Chevron, 2020).  The company’s policy of partnerships, mergers, and acquisitions has paid off handsomely for its bottom line and future success.

       Likewise, experts say that energy demand could increase by 33% by the year 2040, making all sources of energy important: natural gas, crude oil, coal, renewables, and nuclear (Chevron, 2020).  California alone “produced more than 200 million cubic feet of natural gas in 2017 used for heating and cooking in homes and businesses and to generate electricity” (Powering California, 2019).  Chevron has expanded into geothermal, solar, wind, biofuel, fuel cells, and hydrogen energy.  It recently invested in Carbon Clean Solutions, a company which is developing technology that “removes carbon dioxide at a price of $30.00 per ton” (Houston Chronicle, 2020.)  The prototype is expected to come out in 2021.

       The demand for natural gas and liquefied natural gas has intensified as companies and consumers look for cleaner, cheaper sources of energy.  Liquefied natural gas (LNG) can be easily shipped and stored because cooling the gas at temperatures of -260 degrees Fahrenheit shrinks the gas into 600 times smaller its normal volume.  LNG can be re-gasified and transmitted through natural gas pipelines to power plants fueled by natural gas, as well as industrial, residential and commercial consumers.  Markets for both natural gas and LNG have increased in the U.S. since 2007, and Asian countries are demanding more imported product (U.S. Energy Information Administration, 2020).  Chevron Shipping Company has a large fleet of crude oil tankers and LNG carriers to meet this demand (Chevron, 2020).

       Chevron has crude oil and natural gas fields in Colorado, New Mexico, and Texas. In 2018, they produced 651 million cubic feet of natural gas and 77,000 barrels of natural gas liquids (NGL).  In 2018, Chevron’s holdings in the Gulf of Mexico produced 105 million cubic feet of natural gas and 13,000 barrels of NGLs. Its Jack and St. Malo fields produced 139,000 barrels of liquids and 21 million cubic feet of natural gas. Its Big Foot Project produced 25 million cubic feet of natural gas per day. Its Tahiti field in the Gulf produced 22 million cubic feet of natural gas and 3,000 barrels of NGLs.  Its Mad Dog Field yielded 8,000 barrels of liquids and 1 million cubic feet of natural gas.  The Stampede Field produced 4 million cubic feet of natural gas. In California, 25 million cubic feet of natural gas and 400 barrels of NGLs were produced.  In the Appalachian Basin, 240 million cubic feet of natural gas, 4,000 barrels of NGLs, and 1,000 barrels of condensate were produced (Chevron, 2020).

       “The Chevron Pipe Line Company transports crude oil, refined petroleum products, liquefied petroleum (LPG), natural gas, NGLs, and chemicals within the U.S.” (Chevron, 2020).  It manages pipelines for Chevron Phillips Chemical and has financial interests in other U.S. and international pipelines.  Chevron Power and Energy Management Company handles gas-fired and renewable energy power generation.  Cogeneration facilities fueled by natural gas produce electricity and steam and re-use recovered waste heat to optimize oil operations.  Chevron’s Supply and Trading branches in Houston, Texas, London, Singapore, and San Ramon, California provide support for crude oil and natural gas production operations, refining, and marketing. Approximately 5 million barrels of liquids and 5 billion cubic feet of natural gas are traded on the commodities exchange every day.  Chevron’s Gas Supply and Trading group “markets and manages transportation for Chevron’s equity natural gas production.  It also manages all LPG and NGL trading, including supplying refineries and marketing NGLs produced by Chevron’s refineries and Upstream assets” (Chevron, 2020).

       In order to ensure a qualified work force for the future, Chevron invests in education to teach high school students science, technology, engineering, and mathematics (STEM).  Geologists, chemists, IT specialists, healthcare workers, engineers, and other specialists working for Chevron must be experienced professionals in their fields.  They actively encourage girls to become proficient in STEM.  And they support programs to help low-income men and women get the skills they need to get high-paying jobs in the global energy industry (Chevron, 2020).

       More than 100 years later, Chevron is exploring, researching, developing, and utilizing new technologies in order to meet increasing demands for energy.  It continues to be a leader in the global energy industry.

Dawn Pisturino

Thomas Edison State University

December 16, 2020

Copyright 2020-2022 Dawn Pisturino. All Rights Reserved.


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