Supplemental information on oil and gas activities (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Supplemental information on oil and gas activities [Abstract]

Disclosure of detailed information about cost incurred in oil and gas property acquisition, exploration, and development activities [text block]

Development costs include drilling costs and equipment for developmental wells, the construction of facilities for extraction, treatment and storage of hydrocarbons and all necessary costs to maintain facilities for the existing developed reserves.

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Peru		Total
Year ended 31 December 2017
Acquisition of properties
Proved		-		-		-		-		-		-
Unproved		-		-		-		-		-		-
Total property acquisition		-		-		-		-		-		-
Exploration		3,283		37,017		8,080		5,207		743		54,330
Development		10,231		49,268		167		1,210		14,074		74,950
Total costs incurred		13,514		86,285		8,247		6,417		14,817		129,280

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Peru		Total
Year ended 31 December 2016
Acquisition of properties
Proved		-		-		-		-		-		-
Unproved		-		-		-		-		-		-
Total property acquisition
Exploration		5,519		15,233		1,894		2,555		-		25,201
Development		4,566		12,500		-		191		-		17,257
Total costs incurred		10,085		27,733		1,894		2,746		-		42,458

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Peru		Total
Year ended 31 December 2015
Acquisition of properties
Proved		-		-		-		-		-		-
Unproved		-		-		-		-		-		-
Total property acquisition
Exploration		3,598		14,845		1,103		2,562		-		22,108
Development		13,315		14,752		56		3,780		-		31,903
Total costs incurred		16,913		29,597		1,159		6,342		-		54,011

^(a)Includes capitalised amounts related to asset retirement obligations.

Disclosure of capitalized costs relating to oil and gas producing activities disclosure [text block]

The following table presents the capitalised costs as at 31 December 2017, 2016 and 2015, for proved and unproved oil and gas properties, and the related accumulated depreciation as of those dates.

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
At 31 December 2017
Proved properties (a)
Equipment, camps and other facilities		80,611		69,906		843		6,036		157,396
Mineral interest and wells		397,031		291,050		11,159		77,264		776,504
Other uncompleted projects (b)		12,508		11,290		48		70		23,916
Unproved properties		49,702		4,106		2,975		7,585		64,368
Gross capitalised costs		539,852		376,352		15,025		90,955		1,022,184
Accumulated depreciation		(253,764)		(228,793)		(5,700)		(39,509)		(527,766)
Total net capitalised costs		286,088		147,559		9,325		51,446		494,418

^(a) Includes capitalised amounts related to asset retirement obligations.

^(b) Do not include Peru capitalised costs.

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
At 31 December 2016
Proved properties (a)
Equipment, camps and other facilities		80,611		46,785		843		4,174		132,413
Mineral interest and wells		380,037		230,100		4,849		77,255		692,241
Other uncompleted projects		18,274		12,534		36		2,082		32,926
Unproved properties		48,908		4,503		1,894		6,468		61,773
Gross capitalised costs		527,830		293,922		7,622		89,979		919,353
Accumulated depreciation		(230,917)		(190,025)		(5,692)		(29,803)		(456,437)
Total net capitalised costs		296,913		103,897		1,930		60,176		462,916

^(a) Includes capitalised amounts related to asset retirement obligations and impairment loss reversal in Colombia for US$  5,664,000.

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
At 31 December 2015
Proved properties (a)
Equipment, camps and other facilities		79,040		42,852		843		2,097		124,832
Mineral interest and wells		367,722		213,480		4,849		62,941		648,992
Other uncompleted projects		21,830		7,703		290		-		29,823
Unproved properties		70,062		8,180		-		8,758		87,000
Gross capitalised costs		538,654		272,215		5,982		73,796		890,647
Accumulated depreciation		(201,138)		(160,759)		(5,654)		(14,236)		(381,787)
Total net capitalised costs		337,516		111,456		328		59,560		508,860

^(a) Includes capitalised amounts related to asset retirement obligations and impairment loss in Chile and Colombia for US$  104,515,000 and US$  45,059,000, respectively.

Disclosure Of Detailed Information About Results Of Operations For Oil And Gas Producing Activities [text block]

The breakdown of results of the operations shown below summarizes revenues and expenses directly associated with oil and gas producing activities for the years ended 31 December 2017, 2016 and 2015. Income tax for the years presented was calculated utilizing the statutory tax rates.

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
Year ended 31 December 2017
Revenue		32,738		263,076		70		34,238		330,122
Production costs, excluding depreciation
Operating costs		(19,685)		(42,677)		(325)		(7,603)		(70,290)
Royalties		(1,314)		(24,236)		(13)		(3,134)		(28,697)
Total production costs		(20,999)		(66,913)		(338)		(10,737)		(98,987)
Exploration expenses (a)		(1,404)		(3,856)		(707)		(3,985)		(9,952)
Accretion expense (b)		(994)		(683)		-		(930)		(2,607)
Impairment loss reversal for non-financial assets		-		-		-		-		-
Depreciation, depletion and amortization		(22,705)		(38,721)		(8)		(10,659)		(72,093)
Results of operations before income tax		(13,364)		152,903		(983)		7,927		146,483
Income tax benefit (expense)		2,005		(61,161)		344		(2,695)		(61,507)
Results of oil and gas operations		(11,359)		91,742		(639)		5,232		84,976

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
Year ended 31 December 2016
Revenue		36,723		126,228		-		29,719		192,670
Production costs, excluding depreciation
Operating costs		(20,674)		(29,326)		-		(5,738)		(55,738)
Royalties		(1,495)		(7,281)		-		(2,721)		(11,497)
Total production costs		(22,169)		(36,607)		-		(8,459)		(67,235)
Exploration expenses (a)		(21,060)		(11,690)		-		(5,636)		(38,386)
Accretion expense (b)		(897)		(459)		-		(1,198)		(2,554)
Impairment loss reversal for non-financial assets		-		5,664		-		-		5,664
Depreciation, depletion and amortization		(29,890)		(29,439)		-		(12,785)		(72,114)
Results of operations before income tax		(37,293)		53,697		-		1,641		18,045
Income tax benefit (expense)		5,594		(21,479)		-		(558)		(16,443)
Results of oil and gas operations		(31,699)		32,218		-		1,083		1,602

Amounts in US$ '000	Chile		Colombia		Argentina		Brazil		Total
Year ended 31 December 2015
Revenue		44,808		131,897		597		32,388		209,690
Production costs, excluding depreciation
Operating costs		(26,731)		(40,384)		(1,414)		(5,058)		(73,587)
Royalties		(1,973)		(8,150)		(34)		(2,998)		(13,155)
Total production costs		(28,704)		(48,534)		(1,448)		(8,056)		(86,742)
Exploration expenses (a)		(30,499)		(7,132)		(1,159)		(1,103)		(39,893)
Accretion expense (b)		(789)		(890)		-		(896)		(2,575)
Impairment loss for non-financial assets		(104,515)		(45,059)		-		-		(149,574)
Depreciation, depletion and amortization		(37,664)		(50,675)		(91)		(13,401)		(101,831)
Results of operations before income tax		(157,363)		(20,393)		(2,101)		8,932		(170,925)
Income tax benefit (expense)		23,604		7,953		735		(3,037)		29,255
Results of oil and gas operations		(133,759)		(12,440)		(1,366)		5,895		(141,670)

^(a) Do not include Peru costs.

^(b) Represents accretion of ARO liability.

Disclosure Of Detailed Information About Proved Developed And Undeveloped Oil And Gas Reserve Quantities [text block]

The estimated GeoPark net proved reserves for the properties evaluated as of 31 December 2017, 2016 and 2015 are summarised as follows, expressed in thousands of barrels (Mbbl) and millions of cubic feet (MMcf):

	As of 31 December 2017				As of 31 December 2016				As of 31 December 2015
	Oil and  condensate  (Mbbl)		Natural gas (MMcf)		Oil and  condensate  (Mbbl)		Natural gas  (MMcf)		Oil and  condensate  (Mbbl)		Natural gas  (MMcf)
Net proved developed
Chile (a)		720.0		8,688.0		547.0		6,610.0		498.0		4,922.0
Colombia (b)		21,101.0		-		9,502.0		-		8,177.8		-
Brazil (c)		76.0		23,821.0		72.0		29,525.0		120.0		36,158.0
Peru (d)		9,502.0		-		9,316.0		-		-		-
Total consolidated		31,399.0		32,509.0		19,437.0		36,135.0		8,795.8		41,080.0
Net proved undeveloped
Chile (e)		3,423.0		11,329.0		6,052.0		29,690.0		5,455.8		31,593.0
Colombia (f)		44,398.0		-		27,838.0		-		22,245.5		-
Brazil (c)		-		-		-		-		-		-
Peru (d)		9,215.0		-		9,305.0		-		-		-
Total consolidated		57,036.0		11,329.0		43,195.0		29,690.0		27,701.3		31,593.0
Total proved reserves		88,435.0		43,838.0		62,632.0		65,825.0		36,497.1		72,673.0

^(a) Fell Block accounts for 98% of the reserves (99% in 2016 and 91% in 2015) (LGI owns a 20% interest) and Flamenco Block accounts for 2% (1% in 2016 and 9% in 2015) (LGI owns 31.2% interest).

^(b) Llanos 34 Block, Cuerva Block and Yamu Block account for 98%, 1% and 1% (Llanos 34 Block and Llanos 32 Block account for 99% and 1% in 2016, and Llanos 34 Block and Cuerva Block account for 94% and 3% in 2015) of the proved developed reserves, respectively (LGI owns a 20% interest).

^(c) BCAM-40 Block accounts for 100% of the reserves.

^(d) Morona Block accounts for 100% of the reserves.

^(e) Fell Block accounts for 97% of the reserves (99% in 2016 and 100% in 2015) (LGI owns a 20% interest), Flamenco Block accounts for 3% in 2017 (1% in 2016 and nil in 2015) (LGI owns 31.2% interest).

^(f) Llanos 34, Cuerva Block and Yamu Block account for 97%, 2% and 1% (Llanos 34 Block accounts for 100% in 2016 and Llanos 34 Block and Cuerva Block account for 95% and 4% in 2015) of the proved undeveloped reserves, respectively (LGI owns a 20% interest).

Disclosure Of Detailed Information About Increasedecrease In Proved Reserves [text block]

Net proved reserves (developed and undeveloped) of oil and condensate:

Thousands of barrels	Chile		Colombia		Brazil		Peru		Total
Reserves as of 31 December 2014		6,441.9		24,735.3		130.0		-		31,307.2
Increase (decrease) attributable to:
Revisions (a)		119.0		(225.0)		7.6		-		(98.4)
Extensions and discoveries (b)		100.0		10,489.0		-		-		10,589.0
Production		(707.1)		(4,576.0)		(17.6)		-		(5,300.7)
Reserves as of 31 December 2015		5,953.8		30,423.3		120.0		-		36,497.1
Increase (decrease) attributable to:
Revisions (c)		1,148.0		5,779.0		(34.0)		-		6,893.0
Extensions and discoveries (d)		-		6,311.0		-		-		6,311.0
Purchase of Minerals in place (e)		-		-		-		18,621.0		18,621.0
Production		(502.8)		(5,173.3)		(14.0)		-		(5,690.1)
Reserves as of 31 December 2016		6,599.0		37,340.0		72.0		18,621.0		62,632.0
Increase (decrease) attributable to:
Revisions (f)		(2,109.0)		6,315.0		19.0		96.0		4,321.0
Extensions and discoveries (g)		-		29,047.0		-		-		29,047.0
Production		(347.0)		(7,203.0)		(15.0)		-		(7,565.0)
Reserves as of 31 December 2017		4,143.0		65,499.0		76.0		18,717.0		88,435.0

^(a) For the year ended 31 December 2015, the Group’s oil and condensate proved reserves were revised downwards by 0.1 mmbbl. The primary factors leading to the above were:

-     The impact of lower average oil prices resulting in a 2 mmbbl decrease in reserves from the La Cuerva and Yamu blocks in Colombia, and a 1 mmbbl decrease in reserves related to a change in a previously adopted development plan in the Fell Block in Chile.

-      Such decrease was partially offset by better than expected performance from existing wells, of which 2 mmbbl was from the Llanos 34 Block in Colombia and 1 mmbbl from the Fell Block in Chile.

^(b) In Colombia, the extensions and discoveries are primarily due to the Tilo, Jacana, and Chachalaca field discoveries in the Llanos 34 Block.

^(c) For the year ended 31 December 2016, the Group’s oil and condensate proved reserves were revised upward by 7 mmbbl. The primary factors leading to the above were:

-     Better than expected performance from existing wells, resulting in an increase of 9 mmbbl, of which 8 mmbbl was from the Tigana, Jacana and other minor fields in the Llanos 34 Block, and 1 mmbbl was from the Fell Block in Chile.

-     Such increase was partially offset by lower average oil prices impacting the La Cuerva and Yamu blocks in Colombia, resulting in a 2 mmbbl decrease.

^(d) In Colombia, the extensions and discoveries are primarily due to the Jacana field appraisal wells in the Llanos 34 Block.

^(e) In December 2016, we obtained final regulatory approval for our acquisition of the Morona Block in Peru. The Joint Investment and Operating Agreement dated 1 October 2014 and its amendments were closed on 1 December 2016 following the issuance of Supreme Decree 031-2016-MEM.XXX.

^(f) For the year ended 31 December 2017, the Group’s oil and condensate proved reserves were revised upward by 4.3 mmbbl. The primary factors leading to the above were:

-     Better than expected performance from existing wells, from the Tigana and Jacana fields in the Llanos 34 Block, resulting in an increase of 3.8 mmbbl.

-     The impact of higher average oil prices resulting in a 2.5 mmbbl and 0.4 mmbbl increase in reserves from the blocks in Colombia and Chile, respectively.

-     Such increase was partially offset by a decrease in reserves mainly related to a change in a previously adopted development plan in the Fell Block in Chile, resulting in a 2.4 mmbbl decrease.

^(g) In Colombia, the extensions and discoveries are primary due to the Chiricoca, Jacamar, and Curucucu field discoveries in the Llanos 34 Block and the Tigana and Jacana field extentions in the Llanos 34 Block.

Net proved reserves (developed and undeveloped) of natural gas:

Millions of cubic feet	Chile		Brazil		Total
Reserves as of 31 December 2014		33,970.0		40,464.0		74,434.0
Increase (decrease) attributable to:
Revisions (a)		(2,807.6)		2,907.0		99.4
Extensions and discoveries (b)		9,378.0		-		9,378.0
Production		(4,025.4)		(7,213.0)		(11,238.4)
Reserves as of 31 December 2015		36,515.0		36,158.0		72,673.0
Increase (decrease) attributable to:
Revisions (c)		5,078.0		(319.0)		4,759.0
Production		(5,293.0)		(6,314.0)		(11,607.0)
Reserves as of 31 December 2016		36,300.0		29,525.0		65,825.0
Increase (decrease) attributable to:
Revisions (d)		(13,725.0)		59.0		(13,666.0)
Extensions and discoveries (e)		1,187.0		-		1,187.0
Production		(3,745.0)		(5,763.0)		(9,508.0)
Reserves as of 31 December 2017		20,017.0		23,821.0		43,838.0

^(a) For the year ended 31 December 2015, the Group’s proved natural gas reserves were revised by 0.1 billion cubic feet. This was the combined effect of:

-     Better than expected performance from existing wells that resulted in an increase of 13 billion cubic feet (3 billion cubic feet from the Manati field in Brazil and 10 billion cubic feet from the Fell Block in Chile).

-     The above was partially offset by a decrease of 13 billion cubic feet due to lower average gas prices in the Fell and Tierra del Fuego (TdF) blocks in Chile (totalling 3 billion cubic feet) and changes in previously adopted development plan in the Fell Block in Chile (totalling 10 billion cubic feet).

^(b) In Chile, the extensions and discoveries are primary due to the Ache Field discovery and from the extension well in the Fell Block.

^(c) For the year ended 31 December 2016, the Group’s proved natural gas reserves were revised upwards by 5 billion cubic feet. This increase was mainly driven by better than expected performance from existing wells, primarily the Ache field in the Fell Block in Chile, resulting in an addition of 9 billion cubic feet. This increase was partially offset by a reduction of 4 billion cubic feet in the Pampa Larga field, also in the Fell Block.

^(d) For the year ended 31 December 2017, the Group’s proved natural gas reserves were revised downwards by 13.7 billion cubic feet. This was the combined effect of:

-     Removal of proved undeveloped reserves due to changes in previously adopted development plan in the Fell Block in Chile and unsuccessful proved undeveloped executions in the Fell Block in Chile (totalling 21.3 billion cubic feet).

-     The above was partially offset by an increase of 6.8 billion cubic feet due to a better performance in the proved developed producing reserves in the Fell Block in Chile and the impact of higher average prices that resulted in an increase of 0.8 billion cubic feet.

^(e) In Chile, the extensions and discoveries are primary due to the Uaken Field discovery in the Fell Block.

Disclosure Of Detailed Information About Standardized Measure Of Discounted Future Cash Flows Related To Proved Reserves [text block]

Amounts in US$ '000	Chile		Colombia		Brazil		Peru		Total
At 31 December 2017
Future cash inflows		284,711		2,434,954		157,527		1,047,540		3,924,732
Future production costs		(131,788)		(531,751)		(56,311)		(466,110)		(1,185,960)
Future development costs		(57,690)		(187,414)		(7,524)		(235,920)		(488,548)
Future income taxes		(656)		(558,226)		(10,442)		(107,294)		(676,618)
Undiscounted future net cash flows		94,577		1,157,563		83,250		238,216		1,573,606
10% annual discount		(19,338)		(343,561)		(13,293)		(147,682)		(523,874)
Standardized measure of discounted future net cash flows		75,239		814,002		69,957		90,534		1,049,732
At 31 December 2016
Future cash inflows		394,993		873,771		200,713		941,463		2,410,940
Future production costs		(186,700)		(229,593)		(74,116)		(497,187)		(987,596)
Future development costs		(149,785)		(69,996)		(16,352)		(234,328)		(470,461)
Future income taxes		(8,344)		(191,096)		(21,041)		(69,698)		(290,179)
Undiscounted future net cash flows		50,164		383,086		89,204		140,250		662,704
10% annual discount		(14,709)		(113,584)		(15,688)		(109,321)		(253,302)
Standardized measure of discounted future net cash flows		35,455		269,502		73,516		30,929		409,402
At 31 December 2015
Future cash inflows		403,199		1,032,339		221,206		-		1,656,744
Future production costs		(186,933)		(309,394)		(99,832)		-		(596,159)
Future development costs		(112,312)		(99,305)		(16,360)		-		(227,977)
Future income taxes		(17,904)		(195,957)		(16,837)		-		(230,698)
Undiscounted future net cash flows		86,050		427,683		88,177		-		601,910
10% annual discount		(17,895)		(127,586)		(15,861)		-		(161,342)
Standardized measure of discounted future net cash flows		68,155		300,097		72,316		-		440,568

Disclosure Of Detailed Information About Changes In Standardized Measure Of Discounted Future Net Cash Flows [text block]

Amounts in US$ '000	Chile		Colombia		Brazil		Peru		Total
Present value at 31 December 2014		227,658		584,071		112,145		-		923,874
Sales of hydrocarbon , net of production costs		(20,948)		(97,152)		(37,428)		-		(155,528)
Net changes in sales price and production costs		(256,828)		(547,379)		(27,404)		-		(831,611)
Changes in estimated future development costs		28,227		(20,123)		542		-		8,646
Extensions and discoveries less related costs		23,595		174,951		-		-		198,546
Development costs incurred		15,093		29,965		4,872		-		49,930
Revisions of previous quantity estimates		(5,463)		(14,528)		4,845		-		(15,146)
Net changes in income taxes		28,611		101,576		1,573		-		131,760
Accretion of discount		28,210		88,716		13,171		-		130,097
Present value at 31 December 2015		68,155		300,097		72,316		-		440,568
Sales of hydrocarbon , net of production costs		(15,127)		(91,163)		(20,945)		-		(127,235)
Net changes in sales price and production costs		(16,854)		(171,131)		16,366		-		(171,619)
Changes in estimated future development costs		(49,763)		14,941		542		-		(34,280)
Extensions and discoveries less related costs		-		76,641		-		-		76,641
Development costs incurred		9,417		17,302		2,214		-		28,933
Revisions of previous quantity estimates		22,765		70,180		(1,872)		-		91,073
Purchase of Minerals in place		-		-		-		30,929		30,929
Net changes in income taxes		8,256		3,030		(4,020)		-		7,266
Accretion of discount		8,606		49,605		8,915		-		67,126
Present value at 31 December 2016		35,455		269,502		73,516		30,929		409,402
Sales of hydrocarbon , net of production costs		(14,251)		(198,631)		(26,979)		-		(239,861)
Net changes in sales price and production costs		26,928		289,199		(3,000)		69,962		383,089
Changes in estimated future development costs		79,078		(124,053)		8,385		(9,725)		(46,315)
Extensions and discoveries less related costs		-		49,574		-		-		49,574
Development costs incurred		7,146		67,571		-		-		74,717
Revisions of previous quantity estimates		(69,594)		673,622		603		1,133		605,764
Purchase of Minerals in place
Net changes in income taxes		6,097		(258,842)		7,976		(11,828)		(256,597)
Accretion of discount		4,380		46,060		9,456		10,063		69,959
Present value at 31 December 2017		75,239		814,002		69,957		90,534		1,049,732