|
Oil and Gas Exploration and Production Industries Disclosures, Discounted Future Net Cash Flows (Details) (USD $)
In Thousands, unless otherwise specified
|
12 Months Ended |
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] |
|
|
|
| Future cash inflows |
$ 94,612,613 |
$ 92,530,537 |
$ 70,956,169 |
| Future production costs |
(37,184,832) |
(36,060,590) |
(25,760,554) |
| Future development costs |
(17,031,731) |
(15,528,581) |
(11,511,145) |
| Future income taxes |
(11,150,742) |
(11,418,085) |
(9,487,414) |
| Future net cash flows |
29,245,308 |
29,523,281 |
24,197,056 |
| Discount to present value at 10% annual rate |
(12,329,836) |
(13,298,000) |
(11,805,232) |
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves |
16,915,472 |
16,225,281 |
12,391,824 |
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] |
|
|
|
| Balance at Beginning of Period |
16,225,281 |
12,391,824 |
7,541,018 |
| Sales and transfers of oil and gas produced net of production costs |
(5,888,317) |
(5,095,655) |
(3,497,961) |
| Net changes in prices and production costs |
(301,232) |
993,661 |
3,197,403 |
| Extensions, discoveries, additions and improved recovery, net of related costs |
6,082,122 |
6,348,691 |
4,578,274 |
| Development costs incurred |
2,094,600 |
1,545,500 |
1,107,100 |
| Revisions of estimated development costs |
2,341,476 |
(160,990) |
2,172 |
| Revisions of previous quantity estimates |
(3,742,827) |
(609,297) |
(374,126) |
| Accretion of discount |
2,077,217 |
1,577,962 |
960,350 |
| Net change in income taxes |
125,065 |
(1,159,105) |
(1,325,303) |
| Purchases of reserves in place |
69,940 |
5,241 |
265 |
| Sales of reserves in place |
(913,761) |
(658,468) |
(344,649) |
| Changes in timing and other |
(1,254,092) |
1,045,917 |
547,281 |
| Balance at End of Period |
16,915,472 |
16,225,281 |
12,391,824 |
|
United States [Member]
|
|
|
|
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] |
|
|
|
| Future cash inflows |
89,324,274 |
84,518,638 |
62,063,123 |
| Future production costs |
(35,892,997) |
(33,294,343) |
(22,616,039) |
| Future development costs |
(15,825,040) |
(13,811,449) |
(9,596,005) |
| Future income taxes |
(10,247,007) |
(10,539,182) |
(8,503,301) |
| Future net cash flows |
27,359,230 |
26,873,664 |
21,347,778 |
| Discount to present value at 10% annual rate |
(12,177,896) |
(12,498,010) |
(10,718,854) |
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves |
15,181,334 |
14,375,654 |
10,628,924 |
| Per unit price used to calculate future cash inflows - Crude Oil |
99.78 |
97.75 |
76.38 |
| Per unit price used to calculate future cash inflows - Natural Gas Liquids |
36.95 |
51.77 |
43.85 |
| Per unit price used to calculate future cash inflows - Natural Gas |
2.63 |
4.03 |
4.36 |
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] |
|
|
|
| Balance at Beginning of Period |
14,375,654 |
10,628,924 |
5,822,916 |
| Sales and transfers of oil and gas produced net of production costs |
(5,192,392) |
(4,296,926) |
(2,792,005) |
| Net changes in prices and production costs |
(393,585) |
716,682 |
2,468,907 |
| Extensions, discoveries, additions and improved recovery, net of related costs |
5,517,945 |
6,223,552 |
4,319,659 |
| Development costs incurred |
2,042,300 |
1,422,500 |
864,700 |
| Revisions of estimated development costs |
1,987,330 |
(210,919) |
(257,360) |
| Revisions of previous quantity estimates |
(3,286,943) |
(482,496) |
(164,748) |
| Accretion of discount |
1,832,377 |
1,352,740 |
755,001 |
| Net change in income taxes |
174,418 |
(1,049,641) |
(1,171,384) |
| Purchases of reserves in place |
64,317 |
5,241 |
265 |
| Sales of reserves in place |
(869,534) |
(658,468) |
(54,057) |
| Changes in timing and other |
(1,070,553) |
724,465 |
837,030 |
| Balance at End of Period |
15,181,334 |
14,375,654 |
10,628,924 |
|
Canada [Member]
|
|
|
|
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] |
|
|
|
| Future cash inflows |
1,816,369 |
5,056,501 |
6,040,422 |
| Future production costs |
(751,113) |
(2,315,110) |
(2,711,415) |
| Future development costs |
(813,061) |
(1,566,917) |
(1,716,734) |
| Future income taxes |
0 |
(81,590) |
(129,816) |
| Future net cash flows |
252,195 |
1,092,884 |
1,482,457 |
| Discount to present value at 10% annual rate |
146,954 |
(456,537) |
(736,222) |
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves |
399,149 |
636,347 |
746,235 |
| Per unit price used to calculate future cash inflows - Crude Oil |
84.77 |
90.70 |
72.59 |
| Per unit price used to calculate future cash inflows - Natural Gas Liquids |
47.80 |
46.97 |
26.56 |
| Per unit price used to calculate future cash inflows - Natural Gas |
2.22 |
3.28 |
3.67 |
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] |
|
|
|
| Balance at Beginning of Period |
636,347 |
746,235 |
1,037,244 |
| Sales and transfers of oil and gas produced net of production costs |
(159,577) |
(278,910) |
(292,857) |
| Net changes in prices and production costs |
(67,964) |
(57,545) |
(559) |
| Extensions, discoveries, additions and improved recovery, net of related costs |
79,529 |
22,591 |
75,162 |
| Development costs incurred |
23,600 |
48,200 |
175,100 |
| Revisions of estimated development costs |
383,215 |
64,001 |
260,290 |
| Revisions of previous quantity estimates |
(396,408) |
(70,718) |
(38,382) |
| Accretion of discount |
63,635 |
62,725 |
102,022 |
| Net change in income taxes |
0 |
(118,988) |
101,966 |
| Purchases of reserves in place |
0 |
0 |
0 |
| Sales of reserves in place |
(44,227) |
0 |
(290,592) |
| Changes in timing and other |
(119,001) |
218,756 |
(383,159) |
| Balance at End of Period |
399,149 |
636,347 |
746,235 |
|
Trinidad [Member]
|
|
|
|
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] |
|
|
|
| Future cash inflows |
2,408,116 |
2,851,545 |
2,760,819 |
| Future production costs |
(342,113) |
(388,199) |
(384,147) |
| Future development costs |
(171,737) |
(149,884) |
(198,072) |
| Future income taxes |
(691,109) |
(794,856) |
(850,699) |
| Future net cash flows |
1,203,157 |
1,518,606 |
1,327,901 |
| Discount to present value at 10% annual rate |
(242,087) |
(334,399) |
(339,035) |
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves |
961,070 |
1,184,207 |
988,866 |
| Per unit price used to calculate future cash inflows - Crude Oil |
94.46 |
92.50 |
69.56 |
| Per unit price used to calculate future cash inflows - Natural Gas |
3.61 |
3.37 |
2.94 |
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] |
|
|
|
| Balance at Beginning of Period |
1,184,207 |
988,866 |
665,563 |
| Sales and transfers of oil and gas produced net of production costs |
(526,134) |
(504,205) |
(395,379) |
| Net changes in prices and production costs |
162,600 |
331,196 |
721,796 |
| Extensions, discoveries, additions and improved recovery, net of related costs |
0 |
102,548 |
183,453 |
| Development costs incurred |
23,500 |
74,800 |
67,300 |
| Revisions of estimated development costs |
(28,835) |
(14,074) |
(767) |
| Revisions of previous quantity estimates |
(62,285) |
(56,884) |
(175,002) |
| Accretion of discount |
178,298 |
159,715 |
101,549 |
| Net change in income taxes |
88,853 |
9,511 |
(258,354) |
| Purchases of reserves in place |
0 |
0 |
0 |
| Sales of reserves in place |
0 |
0 |
0 |
| Changes in timing and other |
(59,134) |
92,734 |
78,707 |
| Balance at End of Period |
961,070 |
1,184,207 |
988,866 |
|
Other International [Member]
|
|
|
|
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] |
|
|
|
| Future cash inflows |
1,063,854 |
103,853 |
91,805 |
| Future production costs |
(198,609) |
(62,938) |
(48,953) |
| Future development costs |
(221,893) |
(331) |
(334) |
| Future income taxes |
(212,626) |
(2,457) |
(3,598) |
| Future net cash flows |
430,726 |
38,127 |
38,920 |
| Discount to present value at 10% annual rate |
(56,807) |
(9,054) |
(11,121) |
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves |
373,919 |
29,073 |
27,799 |
| Per unit price used to calculate future cash inflows - Crude Oil |
109.94 |
102.86 |
73.88 |
| Per unit price used to calculate future cash inflows - Natural Gas |
5.04 |
5.07 |
5.02 |
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] |
|
|
|
| Balance at Beginning of Period |
29,073 |
27,799 |
15,295 |
| Sales and transfers of oil and gas produced net of production costs |
(10,214) |
(15,614) |
(17,720) |
| Net changes in prices and production costs |
(2,283) |
3,328 |
7,259 |
| Extensions, discoveries, additions and improved recovery, net of related costs |
484,648 |
0 |
0 |
| Development costs incurred |
5,200 |
0 |
0 |
| Revisions of estimated development costs |
(234) |
2 |
9 |
| Revisions of previous quantity estimates |
2,809 |
801 |
4,006 |
| Accretion of discount |
2,907 |
2,782 |
1,778 |
| Net change in income taxes |
(138,206) |
13 |
2,469 |
| Purchases of reserves in place |
5,623 |
0 |
0 |
| Sales of reserves in place |
0 |
0 |
0 |
| Changes in timing and other |
(5,404) |
9,962 |
14,703 |
| Balance at End of Period |
$ 373,919 |
$ 29,073 |
$ 27,799 |