Glossary A-E

Three-dimensional images created by reflecting sound waves off underground rock formations used by oil companies; to characterise reservoirs, design drilling programs and estimate hydrocarbons in place.

The costs associated with abandoning a well or production facility. Such costs typically cover the plugging of wells; removal of well equipment, production tanks and associated installations; and surface remediation.

Reducing the degree or intensity of, or eliminating, pollution, including carbon pollution.

A regulatory framework relating to infrastructure assets such as gas distribution pipelines and electricity poles and wires whereby third parties are granted access on authorised terms and conditions. Access terms may be subject to periodic review by a nominated regulatory body.

The pumping of acid down the wellbore thereby enlarging pore spaces and fractures in rocks to increase fluid flow in the rocks.

The physical process whereby a gas (e.g. methane) may be held on the surface of a material (e.g. coal)

The Australian Energy Market Operator (AEMO) is the independent, member-based organisation that operates the National Electricity Market (NEM) as well as the retail and wholesale gas markets of south eastern Australia. Membership is split between government and industry. Government members of AEMO include the state governments of Queensland, New South Wales, Victoria, South Australia and Tasmania, the Australian Capital Territory and the Commonwealth. Industry members include Australia’s major energy generators, wholesalers and retailers.

A positively-charged particle from the nucleus of an atom, emitted during radioactive decay.

An electric current whose direction reverses cyclically, as opposed to direct current, whose direction remains constant.

A measure applied to the flow of electrons or flow of electric current.

Variation in seismic reflection amplitude with change in distance between shot point and receiver. A technique by which geophysicists seek to determine thickness, porosity, velocity, lithology and fluid content of rocks.

The amount of gas a buyer is entitled to take delivery of during a contract year, under a gas supply contract.

The space between two concentric objects, such as between the wellbore and casing or between casing and tubing, where fluid can flow.

A hard, dense type of coal which contains a high percentage of fixed carbon and a low percentage of volatile matter.

Resulting from or produced by human beings.

An area of the earth's crust where folding has made a dome like shape in the once flat rock layers. Anticlines often provide an environment where oil or natural gas can become trapped beneath the earth's surface, and extracted therefrom.

A specific gravity scale developed by the America Petroleum Institute (API) for measuring the relative density of various petroleum liquids, expressed in degrees. Most values range between 10 and 70 degrees.

Well drilled after the discovery of oil or gas to establish (appraise) the limits of the reservoir, size of reserves and likely production rate of a field.

An underground geological formation or group of formations, containing water. Sources of groundwater for wells and springs. A water-bearing portion of a petroleum reservoir with a water drive.

Class of hydrocarbons that have at least one benzene ring as part of their structure. Generally describes benzene and benzene derivatives.  These products are used as components of unleaded gasolines and as feedstocks for petrochemicals such as cyclohexane and paraxylene, both of which are used in end products like nylons and polyesters.

Any method used to raise oil or gas to the surface through a well, after reservoir pressure has declined to the point at which the well no longer produces by means of natural energy.

Natural gas found in conjunction with oil in reservoirs, and is a by-product of the oil production.

A system of mining that involves the use of a large diameter scroll drill to recover coal near seam outcrops or in open-cut mines where the strip ratio exceeds economic limits.

The process of upgrading capacity or service potential of a transmission or distribution pipeline or network.

In July 2005 The Council of Commission Australian Governments established the Australian Energy Market Commission. The Commission undertakes rule making and market development functions for the national energy markets.

The Australian Energy Regulator undertakes the economic regulation of gas transmission and distribution networks and the enforcement of the national gas law and rules in all jurisdictions apart from Western Australia. In addition, the AER regulates the wholesale electricity market in the national electricity market (NEM).

Angle (generally measured in degrees) between a vertical line and true north.

A natural gas transportation service that requires movement of gas from a point of receipt to a point of delivery such that the contractual direction of movement on the pipeline is in a direction opposite to the physical flow of the gas.

Market situation in which the futures prices are progressively lower in the future delivery months as opposed to Contango where the trend in future prices is upward.

The dry, fibrous residue that remains after the stalks of sugar cane and other plant matter have been crushed and all the juice extracted.

Balancing refers to the process of matching receipts and deliveries of gas by adding or withdrawing gas from a pipeline.

Reference to open hole or without casing e.g barefoot completion.

Measure of the volume of oil or liquids. Barrel is commonly used in the measurement of production rates or reserves: b/d, bpd or bbl/d all refer to the barrels of oil produced per day.

BOE. The oil equivalence of natural gas or other liquids. Usually determined based on the amount of energy relative to oil.

Generating plant that is normally operated to take all or part of the minimum load of a system, and which produces electricity at an essentially constant rate.

Igneous of otherwise non-prospective rocks underlaying a sedimentary basin.

An artifical-lift pumping system used to increase production rate. A beam and crank assembly creates reciprocating motion which connects to a pump that converts the reciprocating motion to vertical fluid movement.

The treatment of mined mineral, making it more concentrated.

Incremental gas or electricity quantities by location offered by Market Participants stacked in price order.

Bcf = 10 to the power of 9 cubic feet.
1Bcf of natural gas is roughly equivalent to 1 PJ.

10 to the power of 9 cubic metres

A geothermal electricity generating plant suited to geothermal resources  employing a closed-loop heat exchange system in which the heat of the geothermal fluid (the “primary fluid”) is transferred to a lower-boiling-point fluid (the “secondary” or “working” fluid), which is thereby vaporised and the vapour used to drive a turbine-generator set.

A biodegradable transportation fuel for use in diesel engines that is produced from organically-derived oils or fats. It may be used either as a replacement for or as a component of diesel fuel.

Energy from biomass refers to the use of plants and animals as energy sources. Biomass can be converted to energy in two ways:

• Directly by producing electricity             
• Indirectly by converting it into a liquid or gas fuel.

A middle rank coal (between sub bituminous and anthracite) formed by additional pressure and heat on lignite. Usually has a high Btu value.

When down hole pressure overcomes the weight of drilling fluid and rises in a well to the surface, out of control.

A small amount of LNG that evaporates from the tank during storage, cooling the tank and keeping the pressure inside the tank constant and the LNG at its boiling point. A rise in temperature is countered by LNG being vented from the storage tank.

A continuous system of mining, whereby a series of parallel roadways or headings are driven into the block of coal and interconnected by roadways known as cut-throughs to form solid coal blocks or pillars. Pillar dimensions vary from 10 to 110 metres.

The hole created by a drill bit.

The pressure in a well, measured by an instrument that is lowered into the borehole on a wire line. It may be measured under flowing or shut-in conditions.

A point on a seismic profile which shows up brighter than surrounding traces because of an increase in amplitude of seismic waves passing from hydrocarbons to water within the pores of a rock.

A standard unit for measuring the quantity of heat energy required to raise the temperature of 1 pound of water by 1 degree Fahrenheit.

An exploration or development project located within an existing province which can share infrastructure and resources with an existing operation.

A controlled power reduction in which the utility decreases the voltage on the power lines, so customers receive weaker electric current. Brownouts can be used if total power demand exceeds the maximum available supply. The typical household does not notice the difference.

The pressure and temperature conditions at which gas “bubbles” out of solution in oil.

A common connection point in a power station switchyard or a transmission network substation.

The energy contained within a certain mass of a material, e.g. a gas.

A cap-and-trade system is an emissions trading system that provides a financial incentive for reducing emissions by setting a cap on total emissions. To cover their emissions cap, emitters are assigned allowances, which can be traded.

An impervious layer of rock that overlies a reservoir rock, thus preventing hydrocarbons from escaping to the surface.

The maximum output an asset can deliver.

A power generation system where the capacity of the system to meet the peak power demand is constrained by the installed generating capacity.

The actual output of a generation plant over a period compared to the expected maximum output from the plant in that period based on 100% availability at the manufacturer’s operating specifications.

A fee paid to a generator to ensure that capacity is available when needed. This system exists in WA but not in the NEM.

A number of approaches are being investigated to capture carbon dioxide emissions from the generation of electricity. Once captured, carbon is transported using high pressure pipelines. Captured carbon dioxide has the potential to be stored in a variety of geological or ocean sites.

Used in emission trading schemes (see emissions trading), where one credit gives the owner the right to emit one tonne of CO².

A major greenhouse gas.

Measure describing how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of carbon dioxide as the reference.

A proposed Government policy aiming to reduce the level of Carbon emissions from Australia. The overall aim is to contribute to stabilising the concentration of greenhouse gases in the atmosphere at 450 parts per million. Subsequently deferred until 2013.

Carbon Sequestration refers to projects that capture and store carbon in a manner that prevents it from being released into the atmosphere. For example, a carbon sink is a reservoir that can absorb or “sequester” carbon dioxide from the atmosphere such as forests, soils and oceans.

Sedimental rock composed of calcium and/or magnesium carbonate e.g. Limestone.

A successful well that has had a steel casing installed to enable future production.

Steel lining used to prevent caving of the sides of a well, to exclude unwanted fluids and to provide means of control of well pressures and oil and gas production.

A petroleum refining process in which heavy hydrocarbon molecules are broken down (cracked) into lighter molecules by passing them over a suitable catalyst (generally heated).

A condition of liquid flow where a liquid vaporises and the vapour bubbles subsequently collapse. Can produce surface damage to pumps; valves etc.

Used to keep the casing stationary in the well and to prevent leakage between strata that have been drilled through.

The output from the Clean Development Mechanism (CDM). A unit of Greenhouse Gas reduction that has been certified under the provisions of the Kyoto Protocol.

A reaction that stimulates its own repetition, in particular where the neutrons originating from nuclear fission cause an ongoing series of fission reactions.

A valve or valves used to control the flow of hydrocarbons from a well by changing the diameter of the opening.

Assembly of valves and fittings located at the head of a well to control flow of oil and gas.

Mass market energy customers switching suppliers.

Sediments derived from the erosion of pre- existing rocks (e.g. sandstone, shale).

A mechanism under the Kyoto Protocol under which industrialised countries with an emissions reduction target can invest  in emissions reduction projects in developing countries rather than in their own country. The output of a CDM is known as certified emission reduction (CER).

Any change in climate, over time, whether due to natural variability or as a result of human activity.

A readily combustible black or brown-black rock, with a composition (including inherent moisture) consists of 50 percent by weight and more than 70 percent by volume of carbonaceous material. Coal can be burnt and used as a fuel in the process of electricity generation.

The process of transforming coal into fuel through the reaction of coal, water and heat.

Gas which is liberated from coal seams during or in preparation for the mining of coal.

Coal in the ground with reasonable prospects for eventual economic extraction, as defined in the JORC code.

Coal seam gas is usually methane in composition and is typically attached to the coal along its natural fractures and cleats. This gas is released when pressure on the coal seam is reduced, usually after water is removed from the seam.

The simultaneous generation of heat and electricity, where both are used for industrial or commercial purposes.

Generated from coking coal after being heated at high temperature in an atmosphere substantially devoid of oxygen, passing through a transient plastic stage in which the coal successively softens, swells and resolidifies into a coherent cellular coke ready for use in the steel making process.

A combined cycle gas turbine generates electricity and then uses the heat from the generation to power a steam turbine and thereby generate additional power. This increases the efficiency of the turbine.

The process of creating light or heat by reacting certain chemicals with oxygen.

Generally defined as non-manufacturing businesses (offices, hotels, motels, restaurants etc).

Producing oil and gas from two or more reservoirs at different depths.

A geological separation of reservoir into compartments as opposed to a continuous reservoir.

The final preparation to ready a well for production. Usually relates to the tubing and wellhead.

The average year-over-year growth rate over a specified period of time.

Natural gas that has been compressed under high pressures (typically between 3,000 and 3,600 psi) and held in a container; expands when released for use as a fuel.

Natural gas is compressed during transportation and storage in order to save space.

Hydrocarbon liquid which forms by precipitation from gas.

A metallic substance capable of transmitting electricity with little resistance. The best conductor at normal temperature ranges is silver. The most common is copper. Some other recently discovered substances called super conductors actually have zero resistance at extremely low temperatures.

A limitation of the capability of a network, load, system or generating unit.

A measure of the movement in the price of a ‘basket’ of consumer goods and services. The change in CPI over a period is a measure of inflation.

Market situation in which the futures prices are progressively higher in the future delivery months as opposed to Backwardation where the trend in future prices is downward.

As defined by the SPE/WPC/AAPG Petroleum Resources Management System: Contingent Resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations, but which are not yet considered mature enough for commercial development due to technological or financial hurdles.

An international price for LPG set in US dollars using the Saudi Aramco Contract Price – a tender process that occurs throughout each month. Australian LPG producers export LPG or sell into the domestic Australian market at price reflective of CP. Similarly, Australian LPG retailers purchase domestically produced or imported LPG based on CP.

A term commonly used to refer to natural gas produced from a moderate to higher permeability reservoir. The reservoir is often sandstone and the gas is extracted using “conventional” drilling and associated extraction techniques.

A quantitative index reflecting the amount of energy need to cool a home or business. The metric is usually expressed at a base temperature. If the temperature of a given day is cooler than the base temperature then the difference is calculated. This difference is summed for the period in question.

An operation whereby a sample of rock being drilled is allowed to pass through the centre of a special bit and be collected in a core barrel mounted directly behind it for future analysis.

 The word cost signifies the price of the goods as loaded and to which is added the freight to get the goods to the destination. The term is used with the name of the destination port, eg. CFR Japan.

Basically the same as “C & F” but the seller must also procure insurance against the risk of loss or damage during the voyage. The seller contracts with the insurer, pays the insurance premium, and then includes this in the price of the goods.

The peak intergovernmental forum in Australia. COAG comprises of:

• The Prime Minister
• State Premiers
• Territory Chief
• Ministers and the President of the Australian
• Local Government Association

A covered gas pipeline is a regulated gas pipeline. The owner or operator of a covered gas pipeline is required to submit a proposed Access Arrangement for the covered pipeline to the Authority for review and approval.

The final period of the Mesozoic era, spanning the time between 145 and 65 million years ago.

A measure of the radioactivity level of a substance i.e. the number of unstable nuclei that are undergoing transformation in the process of radioactive decay. One curie equals the disintegration of 37 billion nuclei per second and is equal to the radioactivity of one gram of Radium-226.

The flow of electrons.

The measure of permeability of rock.

The amount of gas needed daily to satisfy the requirements of a customer. The Annual Contract Quantity (ACQ) divided by 365.

The decrease in the amount of any radioactive material over time due to the transformation of one nuclide into a different nuclide or into a different energy state of the same nuclide. The decay process results in the emission of nuclear radiation (alpha, beta and gamma) and heat.

The rate at which oil or gas can be produced and delivered at specific reservoir conditions and flowing pressures,to meet customer demand.

A point on a pipeline at which gas is delivered to a customer or injected into a storage facility.

Situation where customers reduce their consumption of energy (e.g. electricity) in response to a change in market conditions, e.g. high spot prices. This is a deliberate action taken when demand for power drives spot prices high. Under similar arrangements scheduled loads, such as smelters, may elect to withdraw from the market when the spot price reaches a particular threshold, and resume trading when the price falls to the level of their bids again. This action is beneficial to both the customer and the market in that it allows the smelter to avoid the peaks of high spot prices without damaging their production processes, and provides a short-term response to a supply shortfall in the market. A similar strategy, called load shifting describes a process where specific demand is intentionally moved to a time when there is lower overall demand and lower spot price. Off-peak hot water arrangements are an example of the deliberate shifting of demand to a low-demand period.

Portion of known coal reserves that could be profitably mined and marketed.

A calculation measuring the Replacement Cost, minimum cost of replacing a distribution network in a timely and efficient manner, with an equivalent network.

The elimination of regulation from a previously regulated industry or sector.

The pyramid of latticed steel mounted over the bore hole for drilling and well-servicing purposes.

The process by which a substance is released from or through a surface. The opposite to adsorption or adsorption.

Techniques that use equations developed for similar situations rather than stochastic or statistical approaches.

Well drilled in order to produce oil and gas after an appraisal well has proved the reserves sufficiently large for exploitation.

A relatively mobile mass such as salt or shale that intrudes pre-existing rocks. Diapirs can form anticlines and other structures capable of trapping hydrocarbons.

The inclination from the horizontal of the surface of a geological structure. See “Up Dip” and “Down Dip”.

An electric current that flows steadily in one direction around a circuit. Batteries produce direct current.

Also known as deviated drilling technique - wells are drilled at an angle from a central point. This can increase the exposure of the well to the reservoir and thus achieve improved production performance.

A discount rate is the percentage by which the value of a cash flow in a discounted cash flow (DCF) valuation is reduced for each time period by which it is removed from the present. For listed securities the discount rate is most often calculated using CAPM.

The distillate or middle range of petroleum liquids produced during the processing of crude oil. Products include diesel fuel, heating oil, kerosene and turbine fuel for airplanes.

A distribution network (Voltage 66kV and below), transporting electricity between the transmission network and the end customer.

The transport of gas over a combination of high pressure and low pressure pipelines from a city gate to the usage points of various customers.

A party who participates in the owning, operating and controlling of a distribution network.

Service provided to a distribution network user for use of the distribution network for the conveyance of electricity.

A party who operates a gas distribution pipeline network and who is required to submit or has submitted an access arrangement for that network.

The changes of value, for example, of a meteorological element within the course of a (solar) day. More especially, it denotes the systematic changes that occur during the average day.

Gas which is used domestically for residential, commercial, industrial or electricity generation purposes (i.e. excluding exported gas such as LNG).

A domestic gas asset which produces natural gas.

Located down the slope of a dipping plane or surface.

Commercial operations which are closer to the end user. Includes refining, marketing and distribution.

A large machine used in the surface mining process to remove overburden, or layers of earth and rock, covering a coal seam.

A valved test tool is lowered down a well on the end of the drill string to a specific reservoir formation and the valve opened to capture formation fluids for testing purposes.

The cutting head attached to the drill-pipe.

Free-floating, offshore drilling unit shaped like a ship.

Fluid which is pumped through the drill-string to the bottom of the well, then it rises to the surface through the space between drill-string and bore-hole wall. It acts as a lubricant and is used to control flow.

A well which does not contain any commercially viable oil or gas. It is not currently commercially justifiable to complete the well as an oil or gas producer.

A well completed to produce from two separate reservoirs.

A generator which has the ability to run on two or more fuels.

A regional area encompassing the Australian States and Territories of: Victoria, New South Wales, the Australian Capital Territory, South Australia, Tasmania and Queensland.

Refers to the extensive warming of the central and eastern Pacific that leads to a major shift in weather patterns across the Pacific. In Australia (particularly eastern Australia), El Niño events are associated with an increased probability of drier conditions.

Measure of the resistivity of rock formations down a well which leads to determination of the rock types.

An artifical-lift system utilising a down hole pump which is electrically powered.

A property of matter caused by the movement of electrons. This ‘movement’ is usually initiated by a generator, which is fuelled by any number of energy sources such as coal, water or directly convert from solar radiation in photovoltaic cells.

ESIPC monitors the electricity supply industry in South Australia.

An embedded generator or an embedded generating system means a generating system that is connected to the distribution network as defined in the National Electricity Code.

A certificate that allows the holder to emit an allowance of a controlled pollutant.

Industries which are classed as being emission intensive and trade exposed such as refining companies were to be given assistance in the form of free permits in order to reduce the impact of the proposed CPRS scheme.

Refers to programs that are aimed at reducing the energy used by specific end-use devices and systems, typically without affecting the services provided. These programs reduce overall electricity consumption (reported in megawatt hours), often without explicit consideration for the timing of program-induced savings. Such savings are generally achieved by substituting technically more advanced equipment to produce the same level of end-use services (e.g. lighting, heating, motor drive) with less electricity. Examples include high-efficiency appliances, efficient lighting programs, high-efficiency heating, ventilating and air conditioning (HVAC) systems or control modifications, efficient building design, advanced electric motor drives, and heat recovery systems.

Techniques used to improve oil recovery by restoring formation pressure and to improve flow of fluid in the reservoir. Techniques include chemical flooding (e.g. alkaline flooding), miscible displacement (e.g. CO2 flooding) and thermal recovery (e.g. steam flood).

An alternative mechanism for the production of methane. Carbon dioxide is injected directly into the seam causing the displacement of methane.  ECBM is still at the pilot stage of development, but it is seen as potentially important carbon sequestration methodology.

Uranium in which the proportion of U-235 (to U-238) has been increased above the natural 0.7%. Reactor-grade uranium is usually enriched to about 3.5% U-235, weapons-grade uranium is more than 90% U-235.

The owners / operators of a given project may be required to submit an EIS to identify the possible impact a proposed project may have on the environment. The outcome can determine whether a project proceeds or not in its current form.

The EPA is responsible for the regulation and protection of the environment, in Australia, including water quality, and the control of pollution, waste, noise and radiation.

The proportion of gas that a producing company is entitled to, due to their equity participation in the project.

Established in 2002, the Commission regulates, monitors and enforces a number of different industries in South Australia. The primary objective of ESCoSA is to ensure the long term protection of South Australian consumers.

Where sold separately, is largely ethane gas that has been liquefied through pressurisation. One tonne of ethane is approximately equivalent to 26.8 thousand cubic feet of gas.

A system of climate change policy which governs installations in the European Union. Large Carbon Dioxide emitters in the scheme must monitor and record their annual emissions. The volume of these emissions is then reported, and emitters must then return an equal amount of carbon allowances to the government.

A well drilled into a previously un-explored prospect to test for the presence of oil and or gas.