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Glossary of Technical Terms

Glossary of Technical Terms


2-D seismic                                              

geophysical data that depicts the subsurface strata in two dimensions

3-D seismic                                              

geophysical data that depict the subsurface strata in three dimensions. 3-D seismic typically provides a more detailed and accurate interpretation of the subsurface strata than 2-D seismic


application of a cement plug to close a well and welding of a steel plate to the top of the well; the well is then plugged and abandoned


the standard barrel of crude oil or other petroleum product is 42 US gallons (approximately 159 litres)


billion cubic feet


billion cubic metres


Best estimate                                         

the term ‘best estimate’ is used here as a generic expression for the estimate considered to be the closest to the quantity that will actually be recovered from the accumulation between the date of the estimate and the time of abandonment


barrels of oil equivalent, being for natural gas the energy equivalent on one barrel of oil.  The usual ratio is to equate 6,000 cubic feet to one barrel of oil equivalent


liquid hydrocarbons associated with the production from a primarily natural gas reservoir


means an area consisting of either a single reservoir or multiple reservoirs, all grouped on or related to the same individual geological structural feature and/or stratigraphic condition


natural gas

gas processing facilities                       

together with the laboratory, gathering pipelines and storage facilities (if any), a plant comprising one or more units such that after conditioning the gas will be of pipeline quality as, specified by Gazprom, such units may include dehydration, sweetening and separation of natural gas liquids

gas-water contact                                 

bounding surface in a reservoir above which predominantly gas occurs and below which predominantly water occurs


compounds formed from the elements hydrogen (H) and carbon (C) and existing in solid, liquid or gaseous forms

Kungurian Salt                                        

a layer of salt laid down during the lower Permian age which occurs in the Northern Caspian Petroleum Province

licence area                                             

the particular subsoil plot specified in the subsoil licence issued by the applicable Russian federal authority, which the licence holder has the right to use for the purpose and on the terms specified in the subsoil licence. A licence area may contain one or more fields or may encompass only a portion of a field




million barrels


thousand cubic metres


million barrels of oil equivalent

natural gas                                               

hydrocarbons that are gaseous at one atmosphere of pressure at 20°C. It can be divided into lean gas, primarily methane but often containing some ethane and smaller quantities of heavier hydrocarbons (also called sales gas) and wet gas, primarily ethane, propane and butane as well as smaller amounts of heavier hydrocarbons; partially liquid under atmospheric pressure


naturally occurring liquids and gasses which are predominantly comprised of hydrocarbon compounds

possible reserves                                   

are those unproven reserves that, on the available evidence and taking into account technical and economic factors, have a 10.0 per cent. chance of being produced

probable reserves                                  

are those reserves in which hydrocarbons have been located within the geological structure with a lesser degree of certainty because fewer wells have been drilled and/or certain operational tests have not been conducted. Probable reserves are those reserves that, on the available evidence and taking into account technical and economic factors, have a better than 50.0 per cent. chance of being produced

prospective resources                          

Are those quantities of hydrocarbons which are estimated, on a given date, to be potentially recoverable from undiscovered accumulations

proved reserves                                        

include reserves that are confirmed with a high degree of certainty through an analysis of development history and/or volume method analysis of the relevant geological and engineering data. Proved reserves are those that, based on the available evidence and taking into account technical and economic factors, have a better than 90.0 per cent. chance of being produced

proved plus probable reserves           

sum of the proved reserves and the probable reserves calculated in accordance with SPE standards


quantities of petroleum which are anticipated to be commercially recoverable from known accumulations from a given date forward


a porous and permeable underground formation containing a natural accumulation of producible natural gas and/or oil that is confined by impermeable rock or water barriers and is separate from other reservoirs

risk factor                                                 

for contingent resources means the estimated chance, or probability, that the volumes will be commercially extracted; for prospective resources means the chance or probability of discovering hydrocarbons in sufficient quantity for them to be tested to the surface, this, then, is the chance or probability of the prospective resource maturing into a contingent resource

SPE standards                                         

reserves definitions consistent with those approved in March 1997 by the Society of Petroleum Engineers and the World Petroleum Congresses


below the Kungurian salt layer


above the Kungurian salt layer