| API | American Petroleum Institute. |
| Barrel, Bbl | In the energy industry, a barrel is 42 US gallons measured
at 60° Fahrenheit. This is approximately 159 litres. |
| Base fluid | The continuous phase or suspending medium of a drilling
fluid formulation. |
| CH4 | Methane, the principal constituent of natural gas. One of
the primary greenhouse gases. |
| CO2 | Carbon dioxide, a colourless, odourless, and nonflammable
gas. CO2 emissions occur from the combustion
of fossil fuels. CO2 is a primary greenhouse gas. |
| Crude oil | A mixture of hydrocarbons that exists as a liquid in
natural underground reservoirs and remains liquid at
atmospheric pressure after passing through surface
separating facilities. Crude oil is the raw material that
is refined into gasoline, heating oil, jet fuel, propane,
petrochemicals, and other products. |
| Cuttings | The particles generated by drilling into subsurface
geologic formations and carried out from the wellbore
with the drilling fluid. Examples of drill cuttings include
small pieces of rock varying in size and texture from fine
silt to gravel. |
| Drilling fluid | The circulating fluid (also called ‘mud’) used in the rotary
drilling of wells to clean and condition the hole and to
counterbalance formation pressure. See definitions for
‘water-based drilling fluid’ and ‘non-aqueous drilling
fluid’ below. |
| E&P | Exploration and Production (of hydrocarbons). |
| Emission rate | Emissions of gases per unit of hydrocarbon production. |
| Energy intensity | Energy consumed per unit of hydrocarbon production. |
| Exploration | Study of geological formations to detect the presence of
hydrocarbons. |
| Flare (as an atmospheric emission source category) | Includes emissions generated by burning of gases (or
in some cases liquids) in a thermal destruction device,
including E&P flaring of associated gas (and in some
cases liquids) from oil production or well testing. Typical
equipment sources in this category include:
|
| Flaring | The controlled burning of natural gas produced
in association with oil in the course of oil and gas
exploration and production operations. It also includes
the controlled and safe burning of gas which cannot be
used for commercial or technical reasons. |
| Fresh water | The definition varies in accordance with local statutes and
regulations. Where it is not defined by local regulations,
fresh water is defined for reporting purposes as nonbrackish
water and may include drinking water, potable
water, water used in agriculture, etc. The total dissolved
solids (TDS) concentration of this water type is up to 2000
mg/l. |
| Fuel combustion (as an atmospheric emission source category) | Includes emissions generated through the consumption
of fuel. Typical fuel-consuming equipment types in E&P
operations include:
-
Turbines (e.g., driving compressors, generators and
pumps)
- Internal Combustion Engines
- Heaters
- Boilers / Reboilers
- Mobile sources under company’s operational control
(see IPIECA/API/IOGP Petroleum industry guidelines
for reporting greenhouse gas emissions)
|
| Fugitive emission, fugitive losses | Unintended emissions released to the air, other than
those from stacks or vents from the processing,
transmission, and/or transportation of fossil fuels.
They are often due to equipment leaks and evaporative
processes. |
| Gaseous emission | Gaseous emissions to the atmosphere from flaring
and venting, process and turbine combustion. Includes
fugitive losses from pumps, valves, flanges, pipes, etc. |
| Gas-oil ratio | The volume of gas at atmospheric pressure produced per
unit volume of oil produced. |
| Greenhouse gas | A gas that contributes to the natural greenhouse effect.
The primary six greenhouse gases (GHGs) produced by
human activities are: carbon dioxide, methane, nitrous
oxide, hydrofluorocarbons, perfluorocarbons and
sulphur hexafluoride. For the purpose of this report GHG
considers only CO2 and CH4. |
| Hydrocarbon | An organic chemical compound of hydrogen and carbon
(see petroleum). |
| Hydrocarbon production | Quantity of hydrocarbon gas and/or liquids produced. |
| IPIECA | The global oil and gas industry association for
environmental and social issues. |
| Mud | Common term for drilling fluid. |
| Nitrogen Oxides (NOX) | Nitrogen Oxides represent the sum of nitric oxide (NO)
and nitrogen dioxide (NO2) expressed as NO2 equivalent.
Nitrous oxide (N2O) is not included as a component
of NOX. NOX emissions occur from the combustion of
fossil fuels for industry and transport and are a function
of the type and quantity of fuel burned and the type of
combustion device in which they are burned. |
| NMVOC | Non-methane volatile organic compounds: all
hydrocarbons other than methane that can vaporise at
normal temperature and pressure. |
| Non-aqueous drilling fluid (NADF) | A drilling fluid in which the continuous phase is a waterimmiscible
fluid such as an oleaginous material (e.g.,
mineral oil, enhanced mineral oil, paraffinic oil, or
synthetic material such as olefins and vegetable esters).
NADFs serve many purposes under difficult drilling
conditions. NADFs are usually reused. |
| Normalization | To compare emissions from different regions or sources
it is useful to relate them to the size of the activity
causing the emission. For example, tonnes of CO2 can be
presented by their ratio to tonnes of oil and gas produced.
This procedure is called normalization. |
| Offshore | For this report ‘offshore’ refers to operations that take
place at sea, including inland seas directly connecting to
oceans. Operations in bays, in major inland seas, e.g., the
Caspian Sea, or in other inland seas directly connected to
oceans are counted as offshore. |
| Onshore | For this report ‘onshore’ refers to operations that take
place within a landmass, including swamps, lakes, rivers
and estuaries, but excluding major inland seas. |
| On-site combustion | The local combustion of fuels by E&P companies to
produce energy for their operations. |
| Operator | Term used to describe a company appointed by venture
stakeholders to take primary responsibility for day-to-day
operations for a specific plant or activity. |
| Processing | The separation of oil, gas, and natural gas liquids and the
removal of impurities. |
| Produced water (PW) | The water (generally brine) brought up from the
hydrocarbon-bearing strata during the extraction of oil
and gas, including formation water, injection water, and
any chemicals added downhole or during the oil/water
separation process.
For the purposes of this report produced water
discharges from crude oil and natural gas facilities
are categorised by the source of production and not
the location where they occur, i.e., where production is
offshore and discharges are generated from an onshore
facility, the discharges are reported as offshore. |
| Production | All production activities including production drilling,
process and treatment, flaring and venting, in-field
pipeline transport, and terminal operations.
(see Hydrocarbon production) |
| Purchased energy | Energy purchased in the form of electricity or steam. |
| SO2 | Sulphur dioxide (SO2) can result from the combustion
of H2S and other sulphur containing compounds. In this
report ‘SO2‘ refers to the sum of sulphur dioxide and
sulphur trioxide (SO2) expressed as SO2 equivalent. |
| Source of emissions | In the case of gaseous emissions refers to the process by
which the emissions are released. Source categories are
Energy, Flare, Vent, Fugitive losses and Unspecified. |
| Spill | Any loss of containment from which the released
material reaches the environment (i.e., is not retained
within secondary or other confinement), irrespective of
the quantity recovered. The volume of a spill represents
the gross volume reaching the environment, not a net
volume remaining in the environment after response.
Spills occurring from support and standby vessels
are included but spills of produced water or process
waste water are excluded. Includes loss of containment
resulting from acts of sabotage (such as theft of oil from
pipelines and storage, or vandalism); excludes loss as a
result of ‘acts of terrorism’/attacks on infrastructure. |
| Synthetic-based drilling fluid | A drilling fluid that has a synthetic material as its
continuous phase with water as the dispersed phase.
Synthetic-based drilling fluids are a subset of nonaqueous
drilling fluids. |
| Synthetics | Synthetic material as applied to synthetic-based drilling
fluid means material produced by the reaction of specific
purified chemical feedstock, as opposed to the traditional
base fluids such as diesel and mineral oil which are
derived from crude oil solely through physical separation
processes. |
| Tonne | A metric tonne; equivalent to 1,000 kilograms or 2,205
pounds. |
| Transport | The transfer of hydrocarbons from the site of production
to the point of commercial metering or terminal or
offshore loading device. |
| Upstream industry | Those operations within the industry to the point where
the produced resource is metered into the transportation
system. This includes Exploration and Production. |
| Venting | The controlled release of unburned gas to the
atmosphere. |
| Water-based drilling fluid (mud) | A drilling fluid in which water or a water miscible fluid
is the continuous phase and the suspending medium for
solids, whether or not oil is present. |