Survey of Energy Resources Interim Update 2009
SER 2007 version >Natural Gas Country Notes update
The latest data on natural gas reserves published by Geoscience Australia as a component of its report on the Oil and Gas Resources of Australia (OGRA) relates to the situation as at 1 January 2006. At this point in time there was a total of 906.54 bcm of sales gas in Category 1 (comprising 'current reserves of those fields which have been declared commercial. It includes both proved and probable reserves'). This figure compares with the 1 January 2005 total of 754.66 bcm in this category (also referred to as 'remaining commercial reserves') quoted in OGRA 2004.
Probably as a result of adopting differing definitions of 'proved reserves', other published sources tend to quote substantially higher levels (ostensibly for end-2007), and would appear to include either Category 2 (non-commercial reserves) or to have adopted the McKelvey classification, in which 'economic demonstrated resources' include an element of extrapolation.
So long as China's reserves remain a state secret, it is necessary to have recourse to published sources. For the purposes of the present interim update, Cedigaz estimates have been retained, involving an increase from
2 350 bcm at end-2005 to 3 000 bcm in 2007 (note that Cedigaz's latest published reserves relate to 1 January 2007). Other published assessments of China's gas reserves range from 1 750 to 2 500 bcm, with no two estimates being the same.
Egypt (Arab Republic)
A succession of gas discoveries has boosted Egypt's reserves in recent years. In December 2008, the Chairman of the Egyptian Natural Gas Holding Company (EGAS) stated that by June of that year gas reserves had reached 76 tcf (equivalent to around 2 150 bcm). This implies an increase of 9.1 tcf (258 bcm) over the end-2005 level of 66.9 tcf reported by the Egyptian WEC Member Committee for the 2007 Survey.
Iran (Islamic Republic)
The OPEC Annual Statistical Bulletin 2007 quotes Iran's proved natural gas reserves as 28 080 bcm at end-2007, 5% higher than the end-2005 level of 26 740 bcm reported by the Iranian WEC Member Committee for the 2007 Survey. There appears to be a high degree of consensus amongst the major published sources regarding Iran's gas reserves.
The estimates of proved recoverable reserves of gas adopted for the 2007 Survey and for the present update are derived from the BP Statistical Review of World Energy. The June 2008 edition of this publication quotes Kazakhstan's proved reserves as 1 900 bcm at end-2007 and also implies a retrospective scaling-down of the end-2006 estimate from 3 000 to 1 900 bcm.
While published figures vary widely, rising as high as 3 380 bcm in the 2007 reserves report from the BGR, it may be of some significance that Oil & Gas
Journal's latest tabulation of world gas reserves (December 2008) shows a decrease in Kazakhstan from 100 000 bcf (2 832 bcm) at 1 January 2008 to 85 000 bcf (2 407 bcm) at 1 January 2009.
The level of proved reserves of natural gas adopted for this review reflects the estimates compiled and published by OAPEC in its Annual Statistical Report, as did that in the 2007 Survey. The end-2007 figure is considerably higher than that for end-2005, reflecting major discoveries of non-associated gas in 2006, which have helped to increase Kuwait's proved reserves by 920 bcm, or 58%, over the two years.
Proved reserves, as reported by OAPEC, rose from 6 848 bcm at the end of 2005 to 7 153 at end-2007, implying an increase of 4.5%. Other major published sources quote similar levels.
The Department of Energy and Climate Change reported in September 2008 that total UK proven gas reserves (with a better than 90% chance of being produced) were 343 bcm at end-2007. This compares with a total of 481 bcm two years previously, and represented a decrease of 28.7%. The end-2007 reserves comprised 145 bcm of gas from dry gas fields, 129 bcm of gas from condensate fields and 69 bcm of associated gas from oil fields.
'Probable' reserves (with a better than 50% chance of being technically and economically producible) are put at 304 bcm, whilst 'possible' reserves (with a significant, but less than 50%, chance) are estimated at 293 bcm. Since the end of 2005, there has been an increase of 57 bcm (23.1%) in 'probable' reserves and one of 15 bcm (5.4%) in the 'possible' category.
United States of America
In its 2007 Annual Report on U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves (Advance Summary, October 2008), the Energy Information Administration (EIA) states that there was a significant increase in proved reserves of natural gas in 2007, with additions of 46.1 tcf (circa 1 300 bcm). After deduction of gas production of 19.5 tcf during the year, proved reserves at end-2007 were 237.7 tcf, an increase of 13% over the end-2006 level. The EIA attributes the record addition in reserves to the rapid development of coalbed methane resources and, with the use of advanced technologies, gas in shale reservoirs and tight formations.
Approximately 63% of proved reserve additions were accounted for by discoveries arising from drilling exploratory wells - including extensions to known fields, discovery of new fields, and of new reservoirs in old fields. Most of the remaining additions were due to revisions arising during the development of previously discovered reservoirs or fields.
The OPEC Annual Statistical Bulletin 2007 shows Venezuela's proved gas reserves as increasing from 4 315 bcm at end-2005 to 4 838 bcm at end-2007, a rise of just over 12%. The later level is situated towards the middle of a range of published figures extending from World Oil's 4 304 to BP's 5 150 bcm.
Cedigaz shows Vietnam's proved reserves of natural gas as falling by 145 bcm, from 365 bcm as reported in May 2007 to the latest level of 220 (as at 1 January 2007), which is now in line with the majority of published assessments. The proportionate decrease of 39.7% was the steepest fall among the principal changes in gas reserves identified in this period.