Chevron 2007 Annual Report Download - page 100

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In 2006, revisions accounted for a net increase of 481
BCF for consolidated companies and 26 BCF for affiliates.
For consolidated companies, net increases of 511 BCF interna-
tionally were partially offset by a 30 BCF downward revision
in the United States. Drilling and development activities
added 337 BCF of reserves in Thailand, while Kazakhstan
added 200 BCF, largely due to development activity. Trinidad
and Tobago increased 185 BCF, attributable to improved res-
ervoir performance and a new contract for sales of natural gas.
These additions were partially offset by downward revisions of
224 BCF in the United Kingdom and 130 BCF in Australia
due to drilling results and reservoir performance. U.S. “Other”
had a downward revision of 102 BCF due to reservoir
performance, which was partially offset by upward revisions
of 72 BCF in the Gulf of Mexico and California related to
reservoir performance and development drilling. TCO had
an upward revision of 26 BCF associated with additional
development activity and updated reservoir performance.
In 2007, revisions increased reserves for consolidated
companies by a net 395 BCF and increased reserves for affili-
ated companies by a net 73 BCF. For consolidated companies,
net increases were 209 BCF in the United States and 186
BCF internationally. Improved reservoir performance for
many fields in the United States contributed 130 BCF in the
“Other” region, 40 BCF in California and 39 BCF in the
Gulf of Mexico. Drilling activities added 360 BCF in
Thailand and improved reservoir performance added 188 BCF
in Trinidad and Tobago. These additions were partially offset
by downward revisions of 185 BCF in Australia due to drilling
results and 136 BCF in Nigeria due to field performance.
Negative revisions due to the impact of higher prices were
recorded in Azerbaijan and Kazakhstan. TCO had an upward
revision of 75 BCF associated with improved reservoir per-
form ance and development activities. This upward revision was
net of a negative impact due to higher year-end prices.
Extensions and Discoveries In 2005, consolidated com-
panies increased reserves by 370 BCF, including 167 BCF in
the United States and 118 BCF in the Asia-Pacific region. In
the United States, 99 BCF was added in the “Other” region
and 68 BCF in the Gulf of Mexico, primarily due to drill-
ing activities. The addition in Asia-Pacific resulted primarily
from increased drilling in Kazakhstan.
In 2006, extensions and discoveries accounted for an
increase of 799 BCF for consolidated companies, reflecting a
531 BCF increase outside the United States and a U.S. increase
of 268 BCF. Bangladesh added 451 BCF, the result of devel-
opment activity and field extensions, and Thailand added 59
BCF, the result of drilling activities. U.S. “Other” contributed
157 BCF, approximately half of which was related to South
Texas and the Piceance Basin, and the Gulf of Mexico added
111 BCF, partly due to the initial booking of reserves at the
Great White Field in the deepwater Perdido Fold Belt area.
In 2007, extensions and discoveries accounted for an
increase of 518 BCF worldwide. The largest addition was 330
BCF in Bangladesh, the result of drilling activities. Other
additions were not individually significant.
Purchases In 2005, all except 7 BCF of the 5,656 BCF
total purchases were associated with the Unocal acquisition.
International reserve acquisitions were 4,488 BCF, with
Thailand accounting for about half the volumes. Other sig-
nificant volumes were added in Bangladesh and Myanmar.
In 2006, purchases of natural gas reserves were 35 BCF
for consolidated companies, about evenly divided between
the company’s United States and international operations.
Affiliated companies added 54 BCF of reserves, the result of
conversion of an operating service agreement to a joint stock
company in Venezuela.
In 2007, purchases of natural gas reserves were 141 BCF
for consolidated companies, which include the acquisition of
an additional interest in the Bibiyana Field in Bangladesh.
Affiliated company purchases of 211 BCF related to the for-
mation of a new Hamaca equity affiliate in Venezuela and
an initial booking related to the Angola LNG project.
Sales In 2005, sales of 248 BCF in the “Other” inter-
national region related to the disposition of former-Unocal’s
onshore properties in Canada.
In 2006, sales for consolidated companies totaled 149
BCF, mostly associated with the conversion of a risked service
agreement to a joint stock company in Venezuela.
In 2007, sales were 76 BCF and 175 BCF for consolidated
companies and equity affiliates, respectively. The affiliated
company sales related to the dissolution of a Hamaca equity
affiliate in Venezuela.
Supplemental Information on Oil and Gas Producing Activities