Disclosures About Oil and Gas Producing Activities - Additional Information (Detail) |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
MBoe
MMcf
|
Dec. 31, 2014
MBoe
MMcf
|
Dec. 31, 2013
MBoe
MMcf
|
|
| Reserve Quantities [Line Items] | |||
| Extensions and discoveries | 34,900 | 43,200 | 27,300 |
| Downward revisions | 8,700 | 6,400 | 4,700 |
| Economic revisions | 11,900 | 9,300 | |
| Production | 5,800 | 5,300 | 3.5 |
| Field fuel | MMcf | 1,530 | 1,390 | 560 |
| Significant changes in reserves | Extensions and discoveries for 2015 were 34.9 MMBoe, primarily attributable to our development project in the Wolfcamp shale oil resource play in the Permian Basin. During 2015, we recorded net downward revisions totaling 8.7 MMBoe, including the reclassification of 11.9 MMBoe of proved reserves to unproved reserves. The reserves reclassified are attributable to horizontal and vertical well locations in Project Pangea that are no longer expected to be developed within five years from their initial booking, as required by SEC rules. Revisions also included 13 MMBoe of positive revisions resulting from cost reductions, updated well performance and technical parameters, offset by 9.8 MMBoe of negative revisions due to lower commodity prices. | Extensions and discoveries for 2014 were 43.2 MMBoe, primarily attributable to our development project in the Wolfcamp shale oil resource play in the Permian Basin. During 2014, we recorded downward revisions totaling 6.4 MMBoe, including the reclassification of 9.3 MMBoe of proved undeveloped reserves to probable undeveloped. The reserves reclassified from proved undeveloped to probable undeveloped included 5.8 MMBoe attributable to vertical Canyon locations in Project Pangea that we do not plan to drill within five years from their initial booking, and 3.5 MMBoe attributable to horizontal Wolfcamp locations that are no longer included in our proved development plan. Revisions also included 6.3 MMBoe of positive net revisions attributable to updated well performance and 0.7 MMBoe of positive revisions due to pricing, offset by 4.1 MMBoe of negative revisions resulting from updated technical parameters and costs. | Extensions and discoveries for 2013 were 27.3 MMBoe, primarily attributable to our development project in the Wolfcamp shale oil resource play in the Permian Basin. During 2013, we recorded downward revisions totaling 4.7 MMBoe. Revisions included the reclassification of 7.8 MMBoe of proved undeveloped reserves to probable undeveloped, partially offset by 3.1 MMBoe of positive revisions attributable to gas that will be produced and utilized as field fuel. The reserves reclassified from proved undeveloped to probable undeveloped were attributable to vertical Canyon locations in Project Pangea. Due to our horizontal Wolfcamp development project, including pad drilling, postponement of these deeper locations beyond five years from initial booking was necessary to integrate their development with the shallower Clearfork and Wolfcamp target zones. |
| Period for reclassification of proved reserves to unproved reserves | 5 years | ||
| Positive revisions due to cost reduction, updated well Performance and technical parameters | 13,000 | ||
| Downward revisions due to lower commodity prices | 9,800 | ||
| Positive revisions | (8,710) | (6,379) | (4,692) |
| Positive/(Negative) revision due to pricing | 700 | ||
| Southeast Project Pangea [Member] | |||
| Reserve Quantities [Line Items] | |||
| Downward revisions | 4,100 | ||
| Economic revisions | 5,800 | 7,800 | |
| Positive revisions | 3,100 | ||
| Wolfcamp Shale Oil Resources [Member] | |||
| Reserve Quantities [Line Items] | |||
| Economic revisions | 3,500 | ||
| Positive revisions | 6,300 | ||