| Summary of Changes in Quantities of Proved Oil, NGL and Natural Gas Reserves |
The following table provides a summary of the changes of the total proved reserves for the years ended December 31, 2017, 2016 and 2015, as well as proved developed and proved undeveloped reserves at the beginning and end of each respective year.
|
Total Proved Reserves |
|
Oil
(MBbls) |
|
|
NGLs
(MBbls) |
|
|
Natural Gas
(MMcf) |
|
|
Total
(MBoe) |
|
|
Balance — January 1, 2015 |
|
|
55,338 |
|
|
|
40,907 |
|
|
|
300,020 |
|
|
|
146,248 |
|
|
Extensions and discoveries |
|
|
11,054 |
|
|
|
10,630 |
|
|
|
79,268 |
|
|
|
34,895 |
|
|
Production(1) |
|
|
(1,882 |
) |
|
|
(1,694 |
) |
|
|
(13,262 |
) |
|
|
(5,787 |
) |
|
Revisions to previous estimates |
|
|
(10,014 |
) |
|
|
(357 |
) |
|
|
9,962 |
|
|
|
(8,710 |
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Balance — December 31, 2015 |
|
|
54,496 |
|
|
|
49,486 |
|
|
|
375,988 |
|
|
|
166,646 |
|
|
Extensions and discoveries |
|
|
6,529 |
|
|
|
4,564 |
|
|
|
33,347 |
|
|
|
16,651 |
|
|
Production(1) |
|
|
(1,275 |
) |
|
|
(1,529 |
) |
|
|
(11,734 |
) |
|
|
(4,759 |
) |
|
Revisions to previous estimates |
|
|
(9,719 |
) |
|
|
(4,887 |
) |
|
|
(45,324 |
) |
|
|
(22,161 |
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Balance — December 31, 2016 |
|
|
50,031 |
|
|
|
47,634 |
|
|
|
352,277 |
|
|
|
156,377 |
|
|
Extensions and discoveries |
|
|
10,546 |
|
|
|
9,975 |
|
|
|
76,710 |
|
|
|
33,307 |
|
|
Acquisition of minerals in place |
|
|
710 |
|
|
|
394 |
|
|
|
2,808 |
|
|
|
1,572 |
|
|
Production(1) |
|
|
(1,107 |
) |
|
|
(1,486 |
) |
|
|
(11,148 |
) |
|
|
(4,452 |
) |
|
Revisions to previous estimates |
|
|
(10,120 |
) |
|
|
1,431 |
|
|
|
20,581 |
|
|
|
(5,259 |
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Balance — December 31, 2017 |
|
|
50,060 |
|
|
|
57,948 |
|
|
|
441,228 |
|
|
|
181,545 |
|
|
(1) |
Production included 1,530 MMcf, 1,330 MMcf and 1,319 MMcf related to field fuel in 2015, 2016 and 2017, respectively. |
|
Total Proved Reserves |
|
Oil
(MBbls) |
|
|
NGLs
(MBbls) |
|
|
Natural Gas
(MMcf) |
|
|
Total
(MBoe) |
|
|
Proved Developed Reserves: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
January 1, 2015 |
|
|
17,978 |
|
|
|
19,082 |
|
|
|
138,961 |
|
|
|
60,220 |
|
|
December 31, 2015 |
|
|
15,667 |
|
|
|
20,414 |
|
|
|
154,652 |
|
|
|
61,856 |
|
|
December 31, 2016 |
|
|
13,466 |
|
|
|
20,375 |
|
|
|
150,208 |
|
|
|
58,875 |
|
|
December 31, 2017 |
|
|
13,853 |
|
|
|
23,180 |
|
|
|
176,201 |
|
|
|
66,399 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Proved Undeveloped Reserves: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
January 1, 2015 |
|
|
37,360 |
|
|
|
21,825 |
|
|
|
161,059 |
|
|
|
86,028 |
|
|
December 31, 2015 |
|
|
38,829 |
|
|
|
29,072 |
|
|
|
221,335 |
|
|
|
104,790 |
|
|
December 31, 2016 |
|
|
36,565 |
|
|
|
27,259 |
|
|
|
202,069 |
|
|
|
97,502 |
|
|
December 31, 2017 |
|
|
36,207 |
|
|
|
34,768 |
|
|
|
265,028 |
|
|
|
115,146 |
|
|
| Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Natural Gas Reserves |
The following table provides the standardized measure of discounted future net cash flows at December 31, 2017, 2016 and 2015 (in thousands):
|
|
|
Years Ended December 31, |
|
|
|
|
2017 |
|
|
2016 |
|
|
2015 |
|
|
Future cash flows |
|
$ |
4,451,665 |
|
|
$ |
3,319,551 |
|
|
$ |
4,097,568 |
|
|
Future production costs |
|
|
(1,279,777 |
) |
|
|
(1,054,211 |
) |
|
|
(1,237,888 |
) |
|
Future development costs |
|
|
(982,284 |
) |
|
|
(829,926 |
) |
|
|
(934,814 |
) |
|
Future income tax expense |
|
|
(323,308 |
) |
|
|
(132,834 |
) |
|
|
(307,374 |
) |
|
Future net cash flows |
|
|
1,866,296 |
|
|
|
1,302,580 |
|
|
|
1,617,492 |
|
|
10% annual discount for estimated timing of cash
flows |
|
|
(1,405,265 |
) |
|
|
(1,004,825 |
) |
|
|
(1,157,097 |
) |
|
Standardized measure of discounted future net
cash flows |
|
$ |
461,031 |
|
|
$ |
297,755 |
|
|
$ |
460,395 |
|
|
| Summary of Changes in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Natural Gas Reserves |
The changes in the standardized measure of discounted future net cash flows relating to proved oil and natural gas reserves are as follows (in thousands):
|
|
|
Years Ended December 31, |
|
|
|
|
2017 |
|
|
2016 |
|
|
2015 |
|
|
Balance, beginning of period |
|
$ |
297,755 |
|
|
$ |
460,395 |
|
|
$ |
1,055,815 |
|
|
Net change in sales and transfer prices and in
production (lifting) costs related to future
production |
|
|
229,139 |
|
|
|
(191,841 |
) |
|
|
(1,405,864 |
) |
|
Changes in estimated future development costs |
|
|
(72,439 |
) |
|
|
17,405 |
|
|
|
231,900 |
|
|
Sales and transfers of oil and gas produced during
the period |
|
|
(78,803 |
) |
|
|
(62,835 |
) |
|
|
(91,278 |
) |
|
Net change due to acquisition of minerals in place |
|
|
17,331 |
|
|
|
— |
|
|
|
— |
|
|
Net change due to extensions, discoveries and
improved recovery |
|
|
49,377 |
|
|
|
13,988 |
|
|
|
156,783 |
|
|
Net change due to revisions in quantity estimates |
|
|
(3,817 |
) |
|
|
(25,236 |
) |
|
|
(59,305 |
) |
|
Previously estimated development costs incurred
during the period |
|
|
43,202 |
|
|
|
15,884 |
|
|
|
146,237 |
|
|
Accretion of discount |
|
|
30,789 |
|
|
|
46,040 |
|
|
|
105,582 |
|
|
Other |
|
|
(1,677 |
) |
|
|
(9,500 |
) |
|
|
6,915 |
|
|
Net change in income taxes |
|
|
(49,826 |
) |
|
|
33,455 |
|
|
|
313,610 |
|
|
Standardized Measure of discounted future net
cash flows |
|
$ |
461,031 |
|
|
$ |
297,755 |
|
|
$ |
460,395 |
|
|