GHGRP Petroleum and Natural Gas Systems: Emission Sources
Facilities in this sector report emissions under at least one industry segment. Depending on the industry segment, there are different multiple emission source reporting categories which may be applicable. Read source category definitions below.
This page contains summary information about emission sources in the petroleum and natural gas system sector to characterize the total reported direct emissions from each source reporting category within each industry segment. To explore the petroleum and natural gas systems sector emissions data further, visit the GHGRP Oil and Gas Dashboard.
Reporting Categories
- Natural Gas Pneumatic Device Venting. Pneumatic devices are designed to use the mechanical energy available within a pressurized system to physically actuate (adjust) the device. Devices release gas during normal operations, which is called "venting" or "bleeding."
- Natural Gas Driven Pneumatic Pumps. Pneumatic pumps use pressurized natural gas or air to move a piston or diaphragm, which pumps liquids on the opposite side as pressure is adjusted. Pneumatic pumps are generally used at oil and natural gas production sites where electricity is not readily available.
- Acid Gas Removal Units. Natural gas that contains acidic gases (e.g., hydrogen sulfide) is called "sour" gas. Removal units (sometimes called "sweetening units") are designed to remove the acidic components to meet natural gas quality specifications.
- Dehydrators. Extracted natural gas can contain water and water vapor. Dehydrators use a liquid absorbent (including desiccant, ethylene glycol, diethylene glycol, or triethylene glycol) to absorb water vapor from a natural gas stream.
- Well Venting for Liquids Unloading. During oil and gas production operations, well venting temporarily diverts the flow of natural gas from a well to an atmospheric vent, which changes wellbore pressure and pushes liquids to the surface.
- Gas Well Completions and Workovers Without Hydraulic Fracturing. Well completions are the processes undertaken to make a drilled well into a producing one. These processes encourage the expulsion of drilling and reservoir fluids from to test the reservoir flow and connecting the well bore to the reservoir. Well workovers refer to the processes involved in performing one or more of a variety of remedial operations on producing petroleum and natural gas wells to try and increase production.
- Gas Well Completions and Workovers With Hydraulic Fracturing. Hydraulic fracturing is a process that involves injecting fluids into a well at high pressures to widen and deepen existing fractures in shale formations or to create new ones to allow passage of oil or gas through and up the well. Well completions and workovers may yield a high-rate flowback of injected gas, water, oil, and proppant used to fracture and prop open new fractures.
- Blowdown Vent Stacks. Blowdown vent stacks are elevated vents used to release natural gas and/or carbon dioxide to reduce system pressure in oil and gas production, treatment, or transportation equipment.
- Atmospheric Storage Tanks. An atmospheric storage tank is a vessel used to store liquids that contain one or more hazardous air pollutants (HAPs).
- Transmission Storage Tanks. Storage tanks are used to hold natural gas as it moves from processing plants to and along transmission routes.
- Well Testing. Processes used to collect data on various systems within a well or reservoir to increase the understanding of the reservoir and the hydrocarbons.
- Associated Natural Gas. Refers to the natural gases produced by wells that are flared or vented for regulatory, economic, or technical reasons.
- Flare Stacks. A gas combustion device used to safely release gaseous waste, usually by using a controlled burn.
- Centrifugal Compressors. Machines that increase the pressure of natural gas or carbon dioxide by centrifugal action, drawing in low pressure natural gas and discharging significantly higher-pressure natural gas using mechanical rotating impellers.
- Reciprocating Compressors. Machines that increase the pressure of natural gas or carbon dioxide by positive displacement, employing linear movement of a shaft driving a piston in a cylinder.
- Equipment Leaks, Survey, and Population Counts. Surveys and population counts are used to calculate the extent of leakages from connectors, pumps, compressors, agitators, pressure relief devices, sampling connection systems, open-ended valves or lines, or instruments conveying HAPs.
- Offshore Production Facilities. Offshore production facilities are designed to process and stow oil and gas from subsea wells and to periodically offload the stored oil to a smaller shuttle tanker.
- Enhanced Oil Recovery (EOR). EOR involves injecting carbon dioxide, chemicals, or steam into an existing oil field after primary and secondary efforts are complete to enhance production, restore reservoir pressure, and improve oil displacement or fluid flow in the reservoir.
- Injection Pumps. Used to inject carbon dioxide, chemicals, or steam in the EOR process.
- Hydrocarbon Liquids. The substances produced by the EOR process.
- Combustion Equipment. Machinery designed to burn a fuel source in combination with the oxygen in air, producing heat and energy.