Annual report pursuant to Section 13 and 15(d)

Supplemental Oil and Gas Disclosures - Estimated Quantities of Net Proved, Proved Developed and Proved Undeveloped Oil, Ngls and Natural Gas Reserves (Details)

v3.3.1.900
Supplemental Oil and Gas Disclosures - Estimated Quantities of Net Proved, Proved Developed and Proved Undeveloped Oil, Ngls and Natural Gas Reserves (Details)
Bcfe in Millions
 12 Months Ended
Dec. 31, 2015
MMBoe
Bcfe
MMBbls
Bcf
Dec. 31, 2014
MMBoe
Bcfe
MMBbls
Bcf
Dec. 31, 2013
MMBoe
Bcfe
MMBbls
Bcf
Oil      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 61.7 58.5 54.8
Revisions of previous estimates 4.8 [1] 1.6 [2] (4.3) [3]
Revisions related to sold properties [4] (12.1)    
Extensions and discoveries 2.4 [5] 7.3 [6] 13.9 [7]
Purchase of minerals in place   1.5 [8] 1.5 [9]
Sales of reserves (13.5) [10]   (0.4) [11]
Production (7.8) (7.2) (7.0)
Proved reserves, ending balance 35.5 61.7 58.5
Oil | Proved Developed Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 35.7 36.2  
Proved reserves, ending balance 29.4 35.7 36.2
Oil | Proved Undeveloped Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 26.0 22.3  
Proved reserves, ending balance 6.1 [12] 26.0 22.3
NGLs      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 15.8 15.9 15.2
Revisions of previous estimates (0.9) [1] 0.1 [2] 0.2 [3]
Revisions related to sold properties [4] (4.8)    
Extensions and discoveries 0.2 [5] 0.7 [6] 2.6 [7]
Purchase of minerals in place [8]   1.2  
Sales of reserves [10] (2.1)    
Production (1.6) (2.1) (2.1)
Proved reserves, ending balance 6.6 15.8 15.9
NGLs | Proved Developed Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 10.7 11.1  
Proved reserves, ending balance 6.4 10.7 11.1
NGLs | Proved Undeveloped Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance 5.1 4.8  
Proved reserves, ending balance 0.2 [12] 5.1 4.8
Natural Gas      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcf 254,900 259,900 285,100
Revisions of previous estimates | Bcf 4,900 [1] 14,300 [2] 2,100 [3]
Revisions related to sold properties | Bcf [4] (2,900)    
Extensions and discoveries | Bcf 8,800 [5] 10,100 [6] 22,000 [7]
Purchase of minerals in place | Bcf 6,100 [13] 20,700 [8] 4,400 [9]
Sales of reserves | Bcf (20,200) [10]   (400) [11]
Production | Bcf (46,200) (50,100) (53,300)
Proved reserves, ending balance | Bcf 205,400 254,900 259,900
Natural Gas | Proved Developed Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcf 221,100 232,700  
Proved reserves, ending balance | Bcf 198,500 221,100 232,700
Natural Gas | Proved Undeveloped Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcf 33,800 27,200  
Proved reserves, ending balance | Bcf 6,900 [12] 33,800 27,200
Barrel Equivalent      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | MMBoe [14] 120.0 117.7 117.5
Revisions of previous estimates | MMBoe [14] 4.7 [1] 4.1 [2] (3.8) [3]
Revisions related to sold properties | MMBoe [4],[14] (17.4)    
Extensions and discoveries | MMBoe [14] 4.1 [5] 9.7 [6] 20.2 [7]
Purchase of minerals in place | MMBoe [14] 1.0 [13] 6.1 [8] 2.3 [9]
Sales of reserves | MMBoe [14] (19.0) [10]   (0.5) [11]
Production | MMBoe [14] (17.0) (17.6) (18.0)
Proved reserves, ending balance | MMBoe [14] 76.4 120.0 117.7
Barrel Equivalent | Proved Developed Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | MMBoe [14] 83.3 86.1  
Proved reserves, ending balance | MMBoe [14] 69.0 83.3 86.1
Barrel Equivalent | Proved Undeveloped Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | MMBoe [14] 36.7 31.6  
Proved reserves, ending balance | MMBoe [14] 7.4 [12] 36.7 31.6
Natural Gas Equivalent      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcfe [14] 720.0 705.9 705.1
Revisions of previous estimates | Bcfe [14] 28.0 [1] 25.3 [2] (22.8) [3]
Revisions related to sold properties | Bcfe [4],[14] (104.3)    
Extensions and discoveries | Bcfe [14] 24.4 [5] 58.1 [6] 121.0 [7]
Purchase of minerals in place | Bcfe [14] 6.1 [13] 36.5 [8] 13.7 [9]
Sales of reserves | Bcfe [14] (113.8) [10]   (3.2) [11]
Production | Bcfe [14] (102.3) (105.8) (107.9)
Proved reserves, ending balance | Bcfe [14] 458.1 720.0 705.9
Natural Gas Equivalent | Proved Developed Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcfe [14] 499.7 516.1  
Proved reserves, ending balance | Bcfe [14] 413.5 499.7 516.1
Natural Gas Equivalent | Proved Undeveloped Reserves      
Reserve Quantities [Line Items]      
Proved reserves, beginning balance | Bcfe [14] 220.3 189.8  
Proved reserves, ending balance | Bcfe [14] 44.6 [12] 220.3 189.8
[1] Includes upwards revisions of 7.4 MMBoe at the Ship Shoal 349 field (Mahogany), 1.9 MMBoe at our Brazo A-133 field, 1.3 MMBoe at out Atwater 575 field, 1.3 MMBoe at out Mississippi Canyon 243 field (Matterhorn), 1.1 MMBoe at our Fairway Field, partially offset by downward revisions due to price of 10.7 MMBoe. The revision for price excludes the Yellow Rose field sold during 2015.
[2] Includes upwards revisions due to price of 0.3 MMBoe; positive revisions of 2.4 MMBoe at our Fairway Field, 1.2 MMBoe at our Mississippi Canyon 800 field and 6.4 MMBoe at various fields; and negative revisions of 3.9 MMBoe at our Yellow Rose field and 2.4 MMBoe at various other fields.
[3] Includes upward revision due to price of 1.9 MMBoe; negative revisions of 4.9 MMBoe at our Yellow Rose field for performance and technical changes, 2.3 MMBoe at our High Island 21/22 field for performance, 1.3 MMBoe at our Ship Shoal 349/359 field for performance; and positive performance revisions of 0.7 MMBoe at our Main Pass 98 field, 0.7 MMBoe at our South Timbalier 314, 0.6 MMBoe at our Main Pass 108 field and 0.5 MMBoe our South Timbalier 176 field.
[4] Revisions related to the Yellow Rose field during 2015, which were primarily due to price reductions, up to the date of the sale in October 2015.
[5] Primarily due to increases at Ewing Bank 910.
[6] Includes extensions and discoveries of 4.1 MMBoe at our Yellow Rose field and 4.1 MMBoe at our Mississippi Canyon 782 field.
[7] Includes extensions and discoveries of 12.6 MMBoe at our Yellow Rose field, 4.2 MMBoe at our Ship Shoal 349 field and 1.9 MMBoe at our Mississippi Canyon 698 field.
[8] Primarily due to acquiring additional ownership in the Fairway Field and acquisition of the Woodside Properties.
[9] Primarily due to the acquisition of the Callon Properties.
[10] Related primarily to the sale of the Yellow Rose field in October 2015, which had estimated reserves at the date of sale of 19.0 MMBoe.
[11] Primarily due to the sales of our non-working interests in the Green Canyon 60 field, the Green Canyon 19 field and the West Delta area block 29.
[12] We believe that we will be able to develop all but 1.2 MMBoe of the reserves classified as proved undeveloped (“PUDs”), or approximately 16%, out of the total of 7.4 MMBoe classified as PUDs at December 31, 2015, within five years from the date such reserves were initially recorded. The exception is at the Mississippi Canyon 243 field (Matterhorn) where the field is being developed using a single floating tension leg platform requiring an extended sequential development plan. The platform cannot support a rig that would allow additional wells to be drilled, but can support a rig to allow sidetracking of wells. A portion of the PUDs in this field were originally recorded in our reserves as of December 31, 2010. The development of these PUDs will be delayed until an existing well is depleted and available to sidetrack. Based on the latest reserve report, a well is expected to be drilled to develop the Mississippi Canyon 243 field (Matterhorn) PUDs in 2020.
[13] Primarily due to purchase of additional interest at Brazos A-133.
[14] The conversion to barrels of oil equivalent and cubic feet equivalent were determined using the energy-equivalent ratio of six Mcf of natural gas to one barrel of crude oil, condensate or NGLs (totals may not compute due to rounding). The energy-equivalent ratio does not assume price equivalency, and the energy-equivalent prices for crude oil, NGLs and natural gas may differ significantly.