About Us
Media Center
Concept of CCS
Contact Us
Facts About CCS
Proposed Technologies


Reduction in the degree or intensity of emissions or other pollutants.

Chemical or physical take-up of molecules into the bulk of a solid or liquid, forming either a solution or compound.

Acid gas
Any gas mixture that turns to an acid when dissolved in water (normally refers to H2S + CO2 from sour gas (q.v.)).

A process in which no heat is gained or lost by the system.

The uptake of molecules on the surface of a solid or a liquid.

Planting of new forests on lands that historically have not contained forests.

Aluminium silicate mineral
Natural mineral — such as feldspar, clays, micas, amphiboles — composed of Al2O3 and SiO2 plus other cations.

Organic chemical compound containing one or more nitrogens in -NH2, -NH or -N groups.

Anaerobic condition
Reducing condition that only supports life that does not require free oxygen.

Calcium sulphate: the common hydrous form is called gypsum.

Antarctic Treaty
Applies to the area south of 60 degrees South, and declares that Antarctica shall be used for peaceful purposes only.

Coal with the highest carbon content and therefore the highest rank (q.v.).

Anthropogenic source
Source that is man-made as opposed to natural.

Folded geological strata that is convex upward.

American Petroleum Institute; degree API is a measure of oil density given by (141.5/specific gravity) -131.5.

Geological structure containing water and with significant permeability to allow flow; it is bound by seals.

Assessment unit
A geological province with high petroleum potential.

Assigned amount
The amount by which a Party listed in Annex B of the Kyoto Protocol agrees to reduce its anthropogenic emissions.

Auto Thermal Reforming: a process in which the heat for the reaction of CH4 with steam is generated by partial oxidation of CH4.

The production of electricity for own use.

Back to top

A type of basic igneous rock that is typically erupted from a volcano.

Basel Convention
UN Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal, which was adopted at Basel on March 22, 1989.

The datum against which change is measured.

A geological region with strata dipping toward a common axis or center.

Pertaining to the depth of water.

Pertaining to conditions at depth in bodies of water.

Bicarbonate ion
The anion formed by dissolving carbon dioxide in water, HCO3.

Matter derived recently from the biosphere.

Biomass-based CCS
Carbon capture and storage in which the feedstock (q.v.) is biomass.

Bituminous coal
An intermediate rank of coal falling between the extremes of peat and anthracite, and closer to anthracite.

Refers to catastrophic failure of a well when the petroleum fluids or water flow unrestricted to the surface.

Bohr effect
The pH-dependent change in the oxygen affinity of blood.

Bottom-up model
A model that includes technological and engineering details in the analysis.

In GHG accounting, the separation between accounting units, be they national, organizational, operational, business units or sectors.

Break-even price
The price necessary at a given level of production to cover all costs.

Tendency of a fluid or solid to rise through a fluid of higher density.

Back to top

Cap rock
Rock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir.

Capillary entry pressure
Additional pressure needed for a liquid or gas to enter a pore and overcome surface tension.

Capture efficiency
The fraction of CO2 separated from the gas stream of a source.

Carbon credit
A convertible and transferable instrument that allows an organization to benefit financially from an emission reduction.

Carbon trading
A market-based approach that allows those with excess emissions to trade that excess for reduced emissions elsewhere.

Natural minerals composed of various anions bonded to a CO3 2- cation (e.g. calcite, dolomite, siderite, limestone).

Carbonate neutralization
A method for storing carbon in the ocean based upon the reaction of CO2 with a mineral carbonate such as limestone to produce bicarbonate anions and soluble cations.

A pipe that is inserted to stabilize the borehole of a well after it is drilled.

Coal bed methane.

Carbon dioxide capture and storage.

Clean development mechanism: a Kyoto Protocol mechanism to assist non-Annex 1 countries to contribute to the objectives of the Protocol and help Annex I countries to meet their commitments.

In the context of carbon trading, certifying that a project achieves a quantified reduction in emissions over a given period.

Chemical looping combustion
A process in which combustion of a hydrocarbon fuel is split into separate oxidation and reduction reactions by using a metal oxide as an oxygen carrier between the two reactors.

A magnesium-iron aluminosilicate sheet silicate clay mineral.

Class “x” well
A regulatory classification for wells used for the injection of fluids into the ground.

Claus plant
A plant that transforms H2S into elemental sulphur.

The system of joints, cleavage planes, or planes of weakness found in coal seams along which the coal fractures.

CO2 avoided
The difference between CO2 captured, transmitted and/or stored, and the amount of CO2 generated by a system without capture, net of the emissions not captured by a system with CO2 capture.

CO2 equivalent
A measure used to compare emissions of different greenhouse gases based on their global warming potential.

The additional benefits generated by policies that are implemented for a specific reason.

Cost of electricity, value as calculated by Equation 1 in Section 3.7.

The simultaneous use of more than one fuel in a power plant or industrial process.

Completion of a well
Refers to the cementing and perforating of casing and stimulation to connect a well bore to reservoir.

The quality of agreement between two entities.

Conservative values
Parameter values selected so that a parameter, such as CO2 leakage, is over estimated.

Restriction of movement of a fluid to a designated volume (e.g. reservoir).

Continental shelf
The extension of the continental mass beneath the ocean.

A process for producing iron.

Pertaining to low temperatures, usually under about -100°C.

Back to top

D, Darcy
A non-SI unit of permeability, abbreviated D, and approximately = 1μm2.

A mineral: dihydroxide sodium aluminium carbonate.

Deep saline aquifer
A deep underground rock formation composed of permeable materials and containing highly saline fluids.

Deep sea
The sea below 1,000m depth.

Default emissions factor
An approximate emission factor that may be used in the absence of precise or measured values of an Emissions Factor.

Demonstration phase
Demonstration phase means that the technology is implemented in a pilot project or on a small scale, but not yet economically feasible at full scale.

Dense phase
A gas compressed to a density approaching that of the liquid.

Dense fluid
A gas compressed to a density approaching that of the liquid.

Of a reservoir: one where production is significantly reduced.

Processes that cause changes in sediment after it has been deposited and buried under another layer.

Dissolved Inorganic Carbon.

In geology, the angle below the horizontal taken by rock strata.

The amount of water issuing from a spring or in a stream that passes a specific point in a given period of time.

Discordant sequence
In geology, sequence of rock strata that is markedly different from strata above or below.

A magnesium-rich carbonate sedimentary rock. Also, a magnesium-rich carbonate mineral (CaMgCO3).

Double-grip packer
A device used to seal a drill string equipped with two gripping mechanisms.

Down-hole log
Record of conditions in a borehole.

Drill cuttings
The solid particles recovered during the drilling of a well.

Drill string
The assembly of drilling rods that leads from the surface to the drilling tool.

Fluid flow created in formations by pressure differences arising from borehole operations.

Dry ice
Solid carbon dioxide.

Dynamic miscibility
The attainment of mixing following the prolonged injection of gas into an oilfield.

Back to top

Enhanced coal bed methane recovery; the use of CO2 to enhance the recovery of the methane present in unminable coal beds through the preferential adsorption of CO2 on coal.

Economic potential
The amount of greenhouse gas emissions reductions from a specific option that could be achieved cost effectively, given prevailing circumstances (i.e. a market value of CO2 reductions and costs of other options).

Economically feasible under specific conditions
A technology that is well understood and used in selected commercial applications, such as in a favorable tax regime or a niche market, processing at least 0.1 MtCO2/yr, with a few (less than five) replications of the technology.

Enhanced gas recovery: the recovery of gas additional to that produced naturally by fluid injection or other means.

Emission factor
A normalized measure of GHG emissions in terms of activity, e.g., tons of GHG emitted per ton of fuel consumed.

Emissions credit
A commodity giving its holder the right to emit a certain quantity of GHGs (q.v.).

Emissions trading
A trading scheme that allows permits for the release of a specified number of tons of a pollutant to be sold and bought.

Concerning a chemical reaction that absorbs heat, or requires heat to drive it.

Enhanced gas recovery
See EGR.

Enhanced oil recovery
See EOR.

Entrained flow
Flow in which a solid or liquid, in the form of fine particles, is transported in diluted form by high velocity gas.

Entrainment gas
The gas employed in entrained flow (q.v.).

Enhanced oil recovery: the recovery of oil additional to that produced naturally by fluid injection or other means.

Euphotic zone
The zone of the ocean reached by sunlight.

A rock formed by evaporation.

Concerning a chemical reaction that releases heat, such as combustion.

Ex-situ mineralization
A process where minerals are mined, transferred to an industrial facility, reacted with carbon dioxide and processed.

The formation of different phases during the cooling of a homogeneous fluid.

Extended reach well
Borehole that is diverted into a more horizontal direction to extend its reach.

Microbe living in environments where life was previously considered impossible.

Back to top

Far field
A region remote from a signal source.

In geology, a surface at which strata are no longer continuous, but displaced.

Fault reactivation
The tendency for a fault to become active, i.e. for movement to occur.

Fault slip
The extent to which a fault has slipped in past times.

Fluidized bed combustion: combustion in a fluidized bed (q.v.).

A group of alumino-silicate minerals that makes up much of the Earth’s crust.

The material that is fed to a process.

Flue gas desulphurization.

A process that transforms a gas mixture of CO and H2 into liquid hydrocarbons and water.

The immobilization of CO2 by its reaction with another material to produce a stable compound.

Fixed bed
A gas-solid contactor or reactor formed by a bed of stationary solid particles that allows the passage of gas between the particles.

The injection of a fluid into an underground reservoir.

Flue gas
Gases produced by combustion of a fuel that are normally emitted to the atmosphere.

Fluidized bed
A gas-solid contactor or reactor comprising a bed of fine solid particles suspended by passing a gas through the bed at sufficiently high velocity.

In geology, the bending of rock strata from the plane in which they were formed.

A body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe and name it.

Formation water
Water that occurs naturally within the pores of rock formations.

Deposition of a solid on the surface of heat or mass transfer equipment that has the effect of reducing the heat or mass transfer.

Any break in rock along which no significant movement has occurred.

Fuel cell
Electrochemical device in which a fuel is oxidized in a controlled manner to produce an electric current and heat directly.

Fugitive emission
Any releases of gases or vapors from anthropogenic activities such as the processing or transportation of gas or petroleum.

FutureGen Project
U.S. Government initiative for a new power station with low CO2 emissions.

Back to top

Gas turbine
A machine in which a fuel is burned with compressed air or oxygen and mechanical work is recovered by the expansion of the hot products.

Process by which a carbon-containing solid fuel is transformed into a carbon- and hydrogen-containing gaseous fuel by reaction with air or oxygen and steam.

Geochemical trapping
The retention of injected CO2 by geochemical reactions.

Geological setting
The geological environment of various locations.

Geological time
The time over which geological processes have taken place.

The science of the movement of the Earth’s crust.

The earth, its rocks and minerals, and its waters.

Concerning heat flowing from deep in the earth.

Greenhouse gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydroflurocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6).


Back to top

Hazardous and non-hazardous waste
Potentially harmful and non-harmful substances that have been released or discarded into the environment.

Hazardous waste directive
European directive in force to regulate definitions of waste classes and to regulate the handling of the waste classes.

HAZard and OPerability, a process used to assess the risks of operating potentially hazardous equipment.

Helsinki Convention
International legal convention protecting the Baltic water against pollution.

Henry’s Law
States that the solubility of a gas in a liquid is proportional to the partial pressure of the gas in contact with the liquid.

Higher heating value: the energy released from the combustion of a fuel that includes the latent heat of water.

Host rock
In geology, the rock formation that contains a foreign material.

Hybrid vehicle
Vehicle that combines a fossil fuel internal combustion engine and an alternative energy source, typically batteries.

An ice-like compound formed by the reaction of water and CO2, CH4 or similar gases.

Hydrodynamic trap
A geological structure in which fluids are retained by low levels of porosity in the surrounding rocks.

Concerning water in the geological environment.

Pertaining to the properties of a stationary body of water.

Excessively high CO2 levels in the blood.

Having low rates of oxygen transfer in living tissue.

The phenomenon of a lagging recovery from deformation or other disturbance.

Back to top

International Energy Agency – Greenhouse Gas R&D Program.

Integrated gasification combined cycle: power generation in which hydrocarbons or coal are gasified (q.v.) and the gas is used as a fuel to drive both a gas and a steam turbine.

Rock formed when molten rock (magma) has cooled and solidified (crystallized).

Immature basin
A basin in which the processes leading to oil or gas formation have started, but are incomplete.

Infrared spectroscopy
Chemical analysis using infrared spectroscope method.

The process of using pressure to force fluids down wells.

Injection well
A well in which fluids are injected rather than produced.

A measure of the rate at which a quantity of fluid can be injected into a well.

In-situ mineralization
A process where minerals are not mined: carbon dioxide is injected in the silicate formation where it reacts with the minerals, forming carbonates and silica.

International Seabed Authority
An organization established under the 1982 UN Convention on the Law of the Sea, headquartered in Kingston, Jamaica.

An atom or molecule that has acquired a charge by either gaining or losing electrons.

Intergovernmental Panel on Climate Change.

Back to top

Joint Implementation: under the Kyoto Protocol, it allows a Party with a GHG emission target to receive credits from other Annex 1 Parties.

Back to top

Kyoto Protocol
Protocol to the United Nations Framework Convention on Climate Change, which was adopted at Kyoto on December 11, 1997.

Back to top

To dissolve a substance from a solid.

In respect of carbon trading, the change of anthropogenic emissions by sources or removals by sinks that occurs outside the project boundary.

In respect of carbon storage, the escape of injected fluid from storage.

Levellized cost
The future values of an input or product that would make the NPV (q.v.) of a project equal to zero.

Lower heating value: energy released from the combustion of a fuel that excludes the latent heat of water.

Lignite/sub-bituminous coal
Relatively young coal of low rank with a relatively high hydrogen and oxygen content.

A sedimentary rock made mostly of the mineral calcite (calcium carbonate), usually formed from shells of dead organisms.

Liquefied natural gas.

Science of the nature and composition of rocks.

The outer layer of the Earth, made of solid rock, which includes the crust and uppermost mantle up to 100 km thick.

Records taken during or after the drilling of a well.

London Convention
On the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, which was adopted at London, Mexico City, Moscow and Washington on December 29, 1972.

London Protocol
Protocol to the Convention adopted in London on November 2, 1996 but had not entered into force at the time of writing.

Low-carbon energy carrier
Fuel that provides low fuel-cycle-wide emissions of CO2, such as methanol.

Back to top

Small creature living in the seabed and subsoil, like earthworms, snails and beetles.

Madrid Protocol
A protocol to the 11th Antarctic Treaty to provide for Antarctica’s environmental protection.

Term used for silicate minerals, magmas and rocks, which are relatively high in the heavier elements.

Magmatic activity
The flow of magma (lava).

Marginal cost
Additional cost that arises from the expansion of activity. For example, emission reduction by one additional unit.

The geological process of changing with time. For example, the alteration of peat into lignite, then into sub-bituminous and bituminous coal, and then into anthracite.

Mature sedimentary basins
Geological provinces formed by the deposition of particulate matter under water when the deposits have matured into hydrocarbon reserves.


Medium-gravity oil
Oil with a density of between about 850 and 925kg/m3 (between 20 and 30 API).

A sheet or block of material that selectively separates the components of a fluid mixture.

Of rocks that have been altered by heat or pressure.

Class of silicate minerals with internal plate structure.

Small-scale seismic tremors.

The movement of fluids in reservoir rocks.

Mineral trapa
A geological structure in which fluids are retained by the reaction of the fluid to form a stable mineral.

Miscible displacement
Injection process that introduces miscible gases into the reservoir, thereby maintaining reservoir pressure and improving oil displacement.

The process of reducing the impact of any failure.

The process of measuring the quantity of carbon dioxide stored and its location.

Monte Carlo
A modelling technique in which the statistical properties of outcomes are tested by random inputs.

A very fine-grained sedimentary rock formed from mud.


Back to top

National Greenhouse Gas Inventory
An inventory of anthropogenic emissions by sources and removals by sinks of greenhouse gases prepared by Parties to the UNFCCC.

Natural analogue
A natural occurrence that mirrors in most essential elements an intended or actual human activity.

Natural underground trap
A geological structure in which fluids are retained by natural processes.

Navier-Stokes equations
The general equations describing the flow of fluids.

The region close to a signal source.

Natural gas combined cycle: natural-gas-fired power plant with gas and steam turbines.

Non-hazardous waste
Non-harmful substances that have been released or discarded into the environment.

Net present value: the value of future cash flows discounted to the present at a defined rate of interest.

Numerical approximation
Representation of physico-mathematical laws through linear approximations.

Back to top

Observation well
A well installed to permit the observation of subsurface conditions.

Organization for Economic Co-operation and Development.

Convention for the Protection of the Marine Environment of the North-East Atlantic, which was adopted at Paris on September 22, 1992.

The point at which a particular stratum reaches the earth’s surface.

Rocks and sediments above any particular stratum.

Pressure created in a reservoir that exceeds the pressure inherent at the reservoir’s depth.

The loss of one or more electrons by an atom, molecule or ion.

Oxyfuel combustion
Combustion of a fuel with pure oxygen or a mixture of oxygen, water and carbon dioxide.

Back to top

A device for sealing off a section of a borehole or part of a borehole.

Partial oxidation
The oxidation of a carbon-containing fuel under conditions that produce a large fraction of CO and hydrogen.

Partial pressure
The pressure that would be exerted by a particular gas in a mixture of gases if the other gases were not present. pCO2 The partial pressure (q.v.) of CO2.

Pulverized coal: usually used in connection with boilers fed with finely ground coal.

Pejus level
The level in the ocean below which the functioning of animals deteriorates significantly.

Relating to, or occurring, or living in, or frequenting, the open ocean.

Synthetically produced halocarbons containing only carbon and fluorine atoms. They are characterized by extreme stability, non-flammability, low toxicity and high global warming potential.

Ability to flow or transmit fluids through a porous solid such as rock.

A geological age between 290 and 248 million years ago.

Poisonous to plants.

Piezo-electric transducer
Crystals or films that are able to convert mechanical energy in electrical energy or vice-versa.

A device that is driven down pipelines to inspect and/or clean them.

Point source
An emission source that is confined to a single small location.

Production of more than one form of energy, for example synthetic liquid fuels plus electricity.

Pore space
Space between rock or sediment grains that can contain fluids.

Elastic behaviour of porous media.

Measure for the amount of pore space in a rock.

Post-combustion capture
The capture of carbon dioxide after combustion.

Partial oxidation (q.v.).

Pre-combustion capture
The capture of carbon dioxide following the processing of the fuel before combustion.

Primary legal source
Legal source not depending on authority given by others.

Probability density function
Function that describes the probability for a series of parameter values.

A qualitative assessment of the likelihood that a suitable storage location is present in a given area based on the available information.

Proven reserve
For oil declared by operator to be economical; for gas about which a decision has been taken to proceed with development and production; see Resource.

An area with separate but similar geological formations.

Pressure swing adsorption: a method of separating gases using the physical adsorption of one gas at high pressure and releasing it at low pressure.

Back to top

Quality criterion for coal.

The gain of one or more electrons by an atom, molecule or ion.

Reduction commitment
A commitment by a Party to the Kyoto Protocol to meet its quantified emission limit.

Planting of forests on lands that have previously contained forests but that have been converted to some other use.

Regional scale
A geological feature that crosses an entire basin.

The process of correcting any source of failure.

Energy sources that are inherently renewable such as solar energy, hydropower, wind and biomass.

Rep. Value
Representative value.

Reproductive dysfunction
Inability to reproduce.

A resource (q.v.) from which it is generally economic to produce valuable minerals or hydrocarbons.

A subsurface body of rock with sufficient porosity and permeability to store and transmit fluids.

Residual saturation
The fraction of the injected CO2 that is trapped in pores by capillary forces.

A body of a potentially valuable mineral or hydrocarbon.

A modification of the existing equipment to upgrade and incorporate changes after installation.

Risk assessment
Part of a risk-management system.

Root anoxia
Lack, or deficiency, of oxygen in root zone.

Root zone
Part of the soil in which plants have their roots.

Back to top

Safe Drinking Water Act
An Act of the U.S. Congress originally passed in 1974. It regulates, among other things, the possible contamination of underground water.

Saline formation
Sediment or rock body containing brackish water or brine.

Saline groundwater
Groundwater in which salts are dissolved.

Sand that has turned into a rock due to geological processes.

Saturated zone
Part of the subsurface that is totally saturated with groundwater.

A plausible description of the future based on an internally consistent set of assumptions about key relationships and driving forces. Note that scenarios are neither predictions nor forecasts.

Selective catalytic reduction.

A gas-liquid contacting device for the purification of gases or capture of a gaseous component.

Borderline between the free water and the top of the bottom sediment.

An impermeable rock that forms a barrier above and around a reservoir such that fluids are held in the reservoir.

Secondary recovery
Recovery of oil by artificial means, after natural production mechanisms like overpressure have ceased.

Sedimentary basin
Natural large-scale depression in the Earth’s surface that is filled with sediments.

Seismic profile
A two-dimensional seismic image of the subsurface.

Seismic technique
Measurement of the properties of rocks by the speed of sound waves generated artificially or naturally.

The episodic occurrence of natural or man-induced earthquakes.

A commercial physical absorption process to remove CO2 using glycol dimethylethers.

Clay that has changed into a rock due to geological processes.

Shift convertor
A reactor in which the water-gas shift reaction, CO + H2O = CO2 + H2, takes place.

Simplex orifice fitting
An apparatus for measuring the flow rate of gases or liquids.

The natural uptake of CO2 from the atmosphere, typically in soils, forests or the oceans.

Steam methane reforming: a catalytic process in which methane reacts with steam to produce a mixture of H2, CO and CO2.

Synthetic natural gas: fuel gas with a high concentration of methane produced from coal or heavy hydrocarbons.

Solid oxide fuel cell: a fuel cell (q.v.) in which the electrolyte is a solid ceramic composed of calcium- or yttrium-stabilized zirconium oxides.

Soil gas
Gas contained in the space between soil grains.

Solubility trapping
A process in which fluids are retained by dissolution in liquids naturally present.

Sour gas
Natural gas containing significant quantities of acid gases like H2S and CO2.

Any process, activity or mechanism that releases a greenhouse gas, an aerosol, or a precursor thereof into the atmosphere.

The determination of the number of species into which a single species will divide over time.

Spill point
The structurally lowest point in a structural trap (q.v.) that can retain fluids lighter than background fluids.

Spoil pile
Heap of waste material derived from mining or processing operations.

Special Report on Emissions Scenarios; used as a basis for the climate projections in the TAR (q.v.).

Relating to the stabilization atmospheric concentrations of greenhouse gases.

Stable geological formation
A formation (q.v.) that has not recently been disturbed by tectonic movement.

Steam reforming
A catalytic process in which a hydrocarbon is reacted with steam to produce a mixture of H2, CO and CO2.

A process for retaining captured CO2 so that it does not reach the atmosphere.

Strain gauge
Gauge to determine the deformation of an object subjected to stress.

The order and relative position of strata.

Stratigraphic column
A column showing the sequence of different strata.

Stratigraphic trap
A sealed geological container capable of retaining fluids, formed by changes in rock type, structure or facies.

The enhancement of the ability to inject fluids into, or recover fluids from, a well.

A gas-liquid contacting device, in which a component is transferred from liquid phase to the gas phase.

Structural trap
Geological structure capable of retaining hydrocarbons, sealed structurally by a fault or fold.

Geological feature produced by the deformation of the Earth’s crust, such as a fold or a fault; a feature within a rock such as a fracture; or, more generally, the spatial arrangement of rocks.

Structure contour map
Map showing the contours of geological structures.

Term used in London and OSPAR conventions, meaning the sediments below the seabed.

Sub-bituminous coal
Coal of a rank between lignite (q.v.) and bituminous (q.v.) coal.

Of development, that which is sustainable in ecological, social and economic areas.

At a temperature and pressure above the critical temperature and pressure of the substance concerned. The critical point represents the highest temperature and pressure at which the substance can exist as a vapour and liquid in equilibrium.

Synthesis gas (q.v.).

Synthesis gas
A gas mixture containing a suitable proportion of CO and H2 for the synthesis of organic compounds or combustion.

Fuel, typically liquid fuel, produced by processing fossil fuel.

Back to top

Tail gas
Effluent gas at the end of a process.

The waste resulting from the extraction of value from ore.

Third Assessment Report of the Intergovernmental Panel on Climate Change.

Total capital requirement.

Technical Potential
The amount by which it is possible to reduce greenhouse gas emissions by implementing a technology or practice that has reached the demonstration phase.

Tectonically active area
Area of the Earth where deformation is presently causing structural changes.

Geological age about 65 to 2 million years ago.

Tertiary recovery
Oil generated by a third method; the first is by pressure release or depletion, and the second by oil driven out by the injection of water.

The ocean phenomenon characterized by a sharp change in temperature with depth.

The vertical overturning of water masses due to seasonal heating, evaporation and cooling.

Top-down model
A model based on applying macro-economic theory and econometric techniques to historical data about consumption, prices, etc.

Poisoning, usually of the blood.

Scientific study of poisons and their effects.

A chemical compound or isotope added in small quantities to trace flow patterns.

Transaction cost
The full cost of transferring property or rights between parties.

A geological structure that physically retains fluids that are lighter than the background fluids, e.g. an inverted cup.

Back to top

Ultramafic rocks
An igneous rock consisting almost entirely of iron- and magnesium-rich minerals with a silica content typically less than 45%.

United Nations Convention on the Law of the Sea, which was adopted at Montego Bay on December 10, 1982.

A geological surface separating older from younger rocks and representing a gap in the geological record.

A solution that could contain more solute than is presently dissolved in it.

United Nations Framework Convention on Climate Change, which was adopted at New York on May 9, 1992.

Extremely unlikely to be mined under current or foreseeable economic conditions.

Inclining upward following a structural contour of strata.

Upper ocean
The ocean above 1,000m depth.

Back to top

Vacuum residue
The heavy hydrocarbon mixture that is produced at the bottom of vacuum distillation columns in oil refineries.

Vadose zone
Region from the water table to the ground surface, also called the unsaturated zone because it is partially water-saturated.

In the context of CDM (q.v.), the process of the independent evaluation of a project by a designated operational entity on the basis of set requirements.

The exchange of gases dissolved in sea-water with the atmosphere, or gas exchange, between an animal and the environment.

The proving, to a standard still to be decided, of the results of monitoring (q.v.). In the context of CDM, the independent review by a designated operational entity of monitored reductions in anthropogenic emissions.

Viscous fingering
Flow phenomenon arising from the flow of two largely immiscible fluids through a porous medium.

Back to top

Manmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids.

Well with multiple completions
Well drilled with multiple branching holes and more than one hole being made ready for use.

Well-bore annulus
The annulus between the rock and the well casing.

Wellhead pressure
Pressure developed on surface at the top of the well.

Surface with properties allowing water to contact the surface intimately.

Back to top

Zero-carbon energy carrier
Carbon-free energy carrier, typically electricity or hydrogen.