Summary — Physical Assets and Operations

Overview and Layered Industry Framework

The natural gas industry can be understood through a layered approach that builds from the physical world upward into business and compliance functions. The foundational layer consists of physical assets — the tangible infrastructure used to find, extract, clean, move, store, and deliver natural gas. Above that sits operational management, which governs how people and systems run those assets day to day. Together, these two layers form the subject of this module.

The entire industry follows a single directional flow:

Supply → Transport → Processing → Storage → Demand

This flow can also be described as:

• Acquisition (supply side) → Logistics (middle) → Disposition (demand side)

Understanding where each activity falls within this chain is essential. Confusing a supply-side question with a demand-side answer is a common error that immediately signals disorientation within the industry.

Natural Gas as a Commodity: Types and Sources

Before gas can be transported or traded, it must be produced. Natural gas exists underground in several distinct forms, each requiring different extraction methods and processing approaches.

• Conventional Non-Associated Gas — Pure gas found in underground pockets or reservoirs, with no oil or other hydrocarbons mixed in. This is the simplest and least expensive form to extract and process. Traditional vertical drilling is used to reach the reservoir pocket.

• Conventional Associated Gas — Gas found mixed with oil in the same reservoir. Because both commodities are present together, the gas must be separated from the oil at the surface before further processing. More expensive than non-associated gas to handle.

• Coal Bed Methane — Gas and oil that have migrated so close to the earth's surface that heat and exposure have caused them to harden into coal. What appears as black rock above or near the surface is essentially methane that has solidified. Coal mining extracts this form of energy.

• Tight Sand Gas — Natural gas mixed with sand deposits underground. The gas is literally trapped within tightly packed sand formations, requiring additional separation effort and expense.

• Shale Gas (Frack Gas) — Gas and oil trapped within dense layers of shale rock deep underground. For decades, the industry could see these rich deposits but had no way to access them because the gas existed within the pores of solid rock rather than in open reservoir pockets. The breakthrough came with hydraulic fracturing (fracking) and horizontal drilling, pioneered in Oklahoma. A pipe is drilled vertically and then turned sideways to run along the shale layer. Controlled explosions fracture the rock, sand and water are injected to hold the fractures open, and gas and oil are extracted. This innovation made the United States the world's leading producer of oil and gas.

  • A secondary benefit of horizontal drilling: a single surface rig can now access multiple underground pockets in different directions, dramatically reducing the number of surface rigs needed and minimizing surface disruption.

Once any of these gas types has been cleaned and processed, the resulting product — methane — is indistinguishable regardless of its source. A molecule of methane from shale looks and behaves identically to one from a conventional reservoir.

Liquefied Natural Gas (LNG)

A major market expansion has come through Liquefied Natural Gas (LNG). Pure methane gas can be cooled and chemically treated until it liquefies, dramatically reducing its volume. It is then loaded onto specialized ships and transported globally. Upon arrival at the destination, it is re-gasified (converted back to gas) and distributed to consumers. This has expanded the U.S. natural gas market from a domestic pipeline-only system to a global commodity market — creating new roles in scheduling, shipping logistics, re-gasification operations, and international trading.

Natural Gas Liquids (NGLs) should not be confused with LNG. NGLs are the hydrocarbon byproducts — propane, ethane, butane, heptane, pentane, hexane, and others (collectively called "the anes") — that naturally co-exist with methane and are extracted during processing. Propane tanks for barbecues and acetylene used in metal cutting are both NGL byproducts.

Industry History: Regulation to Deregulation

Understanding the current industry structure requires knowing how it evolved.

The Regulated Era

In the original, regulated natural gas industry, there were essentially two major players:

1. Producers — who extracted the gas
2. Pipelines — who did everything else: processing, transportation, storage, and delivery

The federal government set producer prices, which increased incrementally every year with no competitive pressure to hold them down. Pipelines simply passed the cost plus their own regulated margin to end users. No one was advocating for the consumer.

Deregulation (approximately 1985–1995)

The government recognized that the regulated model produced perpetually rising prices with no advocate for consumers. Deregulation proceeded in phases over roughly a decade:

1. Pipelines were required to choose a core business. Most chose to remain transportation companies, divesting processing and storage operations to separate companies. This broke up vertically integrated monopolies.

2. Marketing companies emerged. Former pipeline employees and industry veterans formed independent marketing companies to act as intermediaries between producers and end users. These marketers introduced competition at every level of the supply chain.

The Marketer's Role

Marketers became the advocate for the end user by:

• Soliciting competing bids from multiple producers, driving prices down
• Negotiating pipeline transportation rates competitively
• Comparing storage costs across providers
• Charging the end user a negotiated fee or margin for this advocacy service

The analogy: just as electric retail companies today compete for residential customers by advertising lower rates, gas marketers competed for commercial, industrial, and utility customers by promising lower delivered gas costs than the prior regulated system provided.

Early Gaming of the System

In the early deregulated years, some marketers exploited loopholes:

• Selling more gas to a customer than they had purchased from a producer
• Relying on the pipeline to cover the shortfall
• Buying replacement gas only when prices fell, pocketing the difference

Pipelines (including the instructor's own employer) lobbied FERC to close these loopholes. The eventual solution was dollar valuation — if a marketer delivered 100,000 units at $2.10 and later needed to return gas, they had to return enough units at the lower current price to equal the original dollar value, not just the same volume.

The Three Segments of the Supply Chain

Every discussion in this industry must be anchored to one of three segments:

1. Supply / Acquisition (Production Side)

This is where gas originates. Key physical assets include:

• Exploration Assets:

  • Seismic exploration (on and offshore) — controlled blasts send shock waves underground; the speed at which they return reveals subsurface reservoir structures (analogous to bat echolocation)
  • Magnetometers and gravimeters — detect subsurface anomalies
  • Satellite infrared imaging (newer technology)

• Extraction Assets:

  • Drilling rigs — tall structures that drive pipe sections (screwed together progressively) down hundreds or thousands of feet to puncture a reservoir
  • Onshore and offshore variants

• Production / Wellhead Assets:

  • Wellhead meter — measures the volume of gas coming out of the ground at the source
  • Christmas Tree — the assembly of valves, gauges, and fittings at the top of a well. Operators adjust these valves to control how much gas is released. Named informally because the arrangement of fittings resembles ornaments on a tree.
  • Horse Head Pump (Pump Jack) — a rocking mechanical device that pumps air and water down into a well to force gas upward when natural reservoir pressure is insufficient. Named for its resemblance to a horse feeding from the ground.

2. Logistics (Middle Segment)

Logistics is composed of exactly three sub-components:

Processing is the only logistics segment that generates revenue — the extracted NGLs (propane, butane, ethane, etc.) are sold, and a portion of those revenues is returned to the gas producer after the plant takes its fee. The plant analogy: a car wash that finds valuables in your car, sells them, and returns the proceeds minus their service fee.

3. Demand / Disposition (Consumption Side)

This is where gas is ultimately consumed. End-use categories include:

• Residential — home heating and cooking; the most important long-term demand driver
• Commercial — businesses, offices, restaurants
• Industrial — manufacturing, chemical plants, large facilities
• Electric Power Generation — natural gas-fired power plants; one of the fastest-growing demand segments

Key consumption-side infrastructure:

• City Gates — the point where a large transmission pipeline hands off gas to a local distribution pipeline. Often a small physical structure housing meters and pressure-regulation equipment, located on the outskirts of a city or town.
• Consumption Meters — meters at individual end-user locations
• Master Meters — larger meters that aggregate flow before it is subdivided into smaller quantities for individual delivery

Physical Pipeline Infrastructure

The U.S. natural gas pipeline grid covers over 300,000 miles of pipe and is the largest physical supply chain in the United States. There are approximately 160 pipeline companies operating this infrastructure.

The Three Pipeline Types

1. Gathering Pipelines

• Small diameter pipe
• Located in production areas
• Collect gas from many individual wells and bring it to a common point
• Common Point Meter — where flows from multiple wells converge
• Primarily intrastate (within a single state)
• Regulated by the state (e.g., the Railroad Commission in Texas)

2. Transmission Pipelines

• Large diameter pipe (potentially 3–5 feet in diameter)
• Cross state lines; long-haul transport
• Approximately 180,000 miles of interstate pipeline in the U.S.
• Capable of transporting over 148 Bcf/day
• Interstate pipelines regulated by FERC (Federal Energy Regulatory Commission)
• Intrastate transmission pipelines regulated by the respective state

3. Distribution Pipelines

• Start at a larger diameter at the city gate, then progressively step down to very small diameter (e.g., ½ inch) at end-user connections
• Operated by Local Distribution Companies (LDCs)
• Approximately 1,200 distribution companies operating over 1.2 million miles of distribution pipe in the U.S.
• Primarily intrastate; regulated by the state
• Deliver gas to residential, commercial, and industrial consumers

Interstate vs. Intrastate Distinction

Note: The natural gas industry was deregulated, but pipelines remain regulated because of their critical role in public safety and energy security.

Processing: Field vs. Plant

Gas coming out of the ground is not market-ready. It contains water, sand, rock, oil, and various hydrocarbon liquids. Processing makes it pipeline-quality.

Field Processing (Cost-Based)

Producers clean their own gas before it reaches a plant, using equipment they own and operate. Analogy: washing your muddy truck at home with a hose before taking it to a detail shop.

Field processing equipment includes:

• Gravity Filters / Gravity Separators — place gas containing mixed impurities into a vessel; heavier materials (rocks, water, liquids) sink to the bottom while lighter methane rises to the top
• Scrubber Filters — mesh-filled vessels (analogous to steel wool or Brillo pads) that trap particulates as gas passes through
• Heater Filters — apply heat to cause heavy impurities to separate and fall
• Liquid Separators — remove liquid droplets from the gas stream

Separated liquids accumulate in tanks in the field; trucks periodically collect these tanks' contents. Travelers in rural areas may notice these tanks in open fields — they are field processing waste/byproduct collection points.

Plant Processing (Fee-Based)

Specialized processing facilities serve large volumes of gas from a production region. The plant charges a fee for processing and returns NGL byproduct revenues to the producer. Analogy: a car wash you pay for, except they also find valuables in your car and return the proceeds.

Plant types are matched to the characteristics of the gas in a given area:

• Gasoline Plants — for gas with high gasoline content
• Dehydration Plants — for gas with high water content
• NGL Plants — for gas rich in propane, butane, ethane, and similar byproducts
• Liquid Separators — present across plant types

Inlet vs. Outlet Characteristics

Bypass Gas: Not all gas entering a plant is fully processed. A portion (10–15%) may bypass the main processing train and be co-mingled with processed gas on the outlet side. This is acceptable because the bypass volume is small relative to total flow and the blended result still meets quality specifications — similar to adding a small amount of blue dye to a large green pool; the blue disperses and becomes invisible.

Odorizer: Pure methane is odorless. A chemical odorant (a sulfur compound producing a rotten-egg smell) is added to the gas supply so that leaks are detectable by human smell, preventing accidental poisoning or explosion. Gas detectors in homes provide an additional safety layer.

Measurement and Valuation

One of the most important concepts in the module is the distinction between physical quantity and energy value.

Physical Measurement

Gas volume in the field is measured in cubic feet — a cube measuring 12 inches × 12 inches × 12 inches.

• Mcf = 1,000 cubic feet (the standard field measurement unit)
• Physical quantity is measured using orifice plates at meter stations

How an Orifice Plate Works:

• A metal plate with a precisely sized central hole is inserted between two pipe flanges
• Gas flowing through the pipe is forced through the smaller hole, creating a pressure differential between the upstream and downstream sides
• Engineers use the pipe diameter, hole size, and the measured pressure differential to calculate the volume of gas flowing through
• Analogous to covering a garden hose nozzle partially with your finger — the restriction creates measurable pressure change

Volume measurement tells you how much gas passed through, but not how much energy it contains.

Energy Measurement

Energy content is measured in BTU (British Thermal Units) — the amount of energy needed to raise (or lower) one pound of water by one degree Fahrenheit.

• The BTU factor of a gas stream cannot be measured in the field; it requires laboratory analysis
• A small gas sample is drawn from the pipeline using a sample tap (resembling a small scuba tank) and sent to a lab
• The lab performs a chemical analysis and returns a BTU factor (e.g., 1.125, meaning each Mcf contains 1.125 times the base energy unit)
• MMBTU = 1,000 BTU energy units at a factor of 1.0 (the trading and pricing unit for natural gas)

The Core Formula

Mcf × BTU Factor = MMBTU

The same volume of gas can have very different energy values and therefore very different prices. Natural gas is bought and sold in MMBTU (energy units), not in Mcf (volume units). Given any two of the three variables (Mcf, BTU factor, MMBTU), the third can be calculated:

• MMBTU ÷ BTU Factor = Mcf
• MMBTU ÷ Mcf = BTU Factor
• Mcf × BTU Factor = MMBTU

Match analogy: Two identical-looking matchboxes may contain 20 matches or 1 match. You cannot tell from the outside. You must open the box (send to the lab) to know the energy value. You would not pay the same price for both boxes.

Log analogy: Fireplace logs are sold by burn duration (3-hour, 5-hour, 7-hour). A longer-burning log costs more because it contains more energy. Natural gas is priced the same way — by energy content, not volume alone.

Compressor Stations

Compressor stations are the engine of the entire pipeline system. Without them, gas would simply sit motionless in the pipe; gas cannot self-direct.

• Large buildings housing compressor units (described as resembling jet engines)
• Compress gas at high pressure, forcing it to flow in the desired direction through the pipe
• Gas naturally slows due to friction and gravity over distance; a new compressor station is needed every 40–100 miles (depending on pipe diameter, flow rate, and pressure requirements)
• Powered by natural gas drawn directly from the pipeline — this consumed gas is called retained fuel
• Some electrically powered stations exist but are rare

Fuel Calculation

Because compressors consume some of the gas they move, shippers must account for this when nominating volumes:

To deliver 10,000 units with a 3% fuel rate:

• Required fuel = 10,000 × 3% = 300 units
• But fuel is consumed on the fuel quantity too (fuel on fuel):
  • 300 × 10% ≈ 3 additional units
• Total nomination needed ≈ 10,303 units to net 10,000 delivered

Fuel rates vary by station age and efficiency (like car fuel economy). Pipelines must get FERC approval to adjust fuel rates — they must prove consumption with historical data.

Henry Hub in Louisiana is a landmark compressor/interconnect facility where approximately seven offshore Gulf of Mexico pipelines come onshore and converge. Its vibration can be felt in the ground from miles away. It was chosen by the industry as the reference pricing point for natural gas — the point at which gas cost is considered "pure" (pre-logistics), used as the basis for NYMEX futures pricing.

Station Equipment

• Scrubbers and filters — clean gas before compression to prevent damage to compressor machinery
• Liquid separators — remove liquids that form due to vibration and temperature changes during transport; liquefied gas cannot be compressed efficiently

Metering and Custody

Measurement is critical for determining ownership, billing, and system integrity.

Custody Meters (Receipt/Delivery Points)

• Located at the point where gas changes hands between parties
• Establish whose gas is being delivered or received (analogous to a bank teller counting your deposit and recording it to your account)
• Found at wellheads, plant inlets/outlets, pipeline interconnects, and city gates
• Once gas enters the commingled pipeline system, individual molecules are no longer tracked — only the credited volume (the "ledger entry") is retained

Check Meters

• Located at intermediate points along a pipeline (between custody meters)
• Verify that the volume entering a segment equals the volume exiting (minus known fuel consumption and losses)
• Any significant discrepancy triggers an investigation — crews or drones are dispatched to inspect for leaks
• Analogous to the bank vault count: total deposits should equal total vault contents at end of day

Meter Stations

A physical facility housing one or more meters, including the measurement equipment, pressure regulation, and data transmission infrastructure.

Storage Facilities

Storage acts as inventory management — the "pantry" of the natural gas industry.

Types of Storage

• Depleted Reservoirs (86% of capacity) — former natural gas reservoirs that have been emptied through production. Because nature designed them to hold pressurized gas, they are ideal for re-use as storage. They are pressurized with working gas and base gas to enable injection and withdrawal.
• Aquifers — underground water-bearing formations that can be converted to gas storage
• Salt Caverns — underground cavities dissolved in salt formations; faster injection/withdrawal rates than reservoirs, ideal for peak demand response
• Above-Ground Tanks — man-made, typically used for smaller volumes or specialty products

Storage Purposes

• Base Load Storage — maintains steady supply across seasonal demand swings (winter heating demand vs. summer lows)
• Peak Load Storage — provides rapid-response supply during short-term demand spikes (cold snaps, heat waves driving power generation demand)

Geographic Distribution

• Majority of storage is in the northern/midwestern U.S. — close to the highest-demand consumption markets (just as consumers store food in their own homes, not at the farm)
• Some storage exists near production areas to allow producers to continue operating when demand is temporarily low
• Approximately 123 storage operators control ~400 underground facilities with ~4,059 Bcf of capacity and ~85 Bcf/day deliverability
• LDCs (Local Distribution Companies) own the majority of storage because they are the last line of defense in ensuring their customers receive gas safely

Pipeline Maintenance and Safety

Intelligent Pigs

• Intelligent Pigs — football-shaped metal devices inserted into a pipeline at one location and retrieved at another
• Carry sensors that measure the internal diameter of the pipe as they travel through it
• Narrowing diameter indicates erosion, corrosion, or mechanical damage
• When a problem is identified, the affected pipe segment is isolated (valves closed on both sides), depressurized, cut out, and replaced
• Travel is powered by the gas pressure in the pipeline itself

Cleaning Pigs

• Non-intelligent (sometimes called "dumb pigs" or cleaning pigs)
• Covered in wire mesh or abrasive material (analogous to steel wool or Brillo pads)
• Scrub the interior walls of the pipe to remove rust, scale, wax, and debris
• Maintain flow efficiency and pipe integrity

Pipeline Burial and Right-of-Way

• Pipelines are buried underground using trenches, sometimes excavated by controlled explosive charges for speed
• Grass and landscape are restored after burial; the pipeline is often undetectable on the surface
• Companies must secure right-of-way across private land
• Farm Taps — an arrangement in which a pipeline company provides a farmer with a free gas connection tapped directly off the transmission line in exchange for the right to cross the farmer's land. The farmer uses the gas for personal/farm purposes only and cannot resell it.
• Pipeline safety monitoring now uses drones (and previously manned aircraft) to fly above pipeline routes, looking for signs of leaks (brown or dead vegetation, frost patterns in winter, etc.)

Key Connection Points Along the Pipeline

• Industrial Taps — a large-diameter direct connection from a transmission pipeline to a high-volume industrial consumer (factory, power plant, glass manufacturer) that is located close to the main line. Bypasses the LDC distribution system because the volume is too large for small-diameter distribution pipe.
• Farm Taps — (see above) free gas in exchange for land access
• City Gates — the formal transfer point between a transmission pipeline and an LDC's distribution system. Gas volume is often reported as an aggregate "Chicago City Gate" even though physical delivery occurs at dozens or hundreds of individual meter points around the city.
• Interconnects — any point where two separately owned pipeline systems meet to exchange gas custody. Enables a single gas transaction to travel across multiple pipeline systems (analogous to connecting flights on different airlines).

Operations: Scheduling, Planning, and Gas Control

Gas Scheduling

Schedulers are responsible for coordinating the movement of gas from supply points to delivery points across the pipeline system. Key considerations:

• Operational vs. Contractual Flow: The physical gas flowing through a pipe at any moment may not be the same gas that a contract specifies. A scheduler may fulfill a contract to deliver gas in Chicago by using gas already held in a Chicago-area storage facility rather than physically moving gas from Texas — just as a retailer might fulfill an order from local warehouse inventory rather than shipping from the factory.
• Complexity: Schedulers optimize routing to minimize cost while honoring contractual commitments
• Multi-pipeline transactions: A single gas movement from production to delivery may cross three or more pipeline systems, each requiring a separate nomination and coordination

Pipeline Allocations

When physical gas flows do not exactly match nominated/contracted volumes (which is common due to the imprecise nature of large pressurized systems), allocations determine how the difference is distributed:

Gas Planning

• Long-Term Forecasting — multi-year demand projections used for infrastructure investment decisions
• Short-Term Forecasting — week-ahead and day-ahead projections adjusting for weather, operational constraints, and demand fluctuation
• Key variables: seasonality, weather/temperature, capacity availability, demand fluctuation (events, industrial schedules, etc.)

Bid Week

• Occurs during the last week of each month (typically the last 5 business days before month-end)
• Industry participants (producers, marketers, pipelines, LDCs) negotiate and agree on gas supply contracts for the coming month
• Establishes the baseline plan for the month: volumes, prices, delivery points, and schedules
• Analogous to a restaurant ordering its food supply for the coming month — establishing what will be delivered, when, and at what price

Morning Meeting (Daily Operational Meeting)

• Held every business day at the start of trading/operations
• Attended by scheduling, marketing, storage, and pipeline personnel
• Reviews what changed overnight (weather forecast updates, pipeline outages, demand signals)
• Adjusts the day's operational plan based on actual conditions vs. the bid-week baseline
• Analogous to an American football team's pre-play huddle: assignments are given, adjustments made, and everyone executes their role

LDC Responsibilities

Local Distribution Companies carry the heaviest operational burden in terms of public safety:

• Deliverability — ensuring every customer receives gas on demand
• Stable and safe operations — maintaining system pressure within safe operating ranges
• Upstream pipeline coordination — constant communication with transmission pipelines about volumes, timing, and delivery points
• Storage management — injecting and withdrawing gas to balance supply with variable demand
• Curtailments and flow orders — pre-planned protocols for reducing gas delivery when supply is constrained; priority order protects hospitals, senior care facilities, and residences before commercial/industrial customers

Industry Scale (Reference Data)