	2017
	Cost											Depreciation
Account	Beginning of the year		Additions		Retirements		Transfers			End of the year		Accumulated at the beginning of the year		Retirements		For the year		Rate %		Accumulated at at the end of the year		Net book value
Pipelines		3,646,711		-		-		275,806			3,922,517		1,606,593		-		91,452		2.2		1,698,045		2,224,472
Compressor plants		1,564,820		1,418		11,274		289,319			1,844,283		993,793		8,988		99,716		3.3 to 25		1,084,521		759,762
Other plants		2,868		-		-		-			2,868		651		-		97		3.3		748		2,120
Stations of regulation and/ormeasurement of pressure		136,288		-		-		5,594			141,882		93,207		-		5,432		4.0		98,639		43,243
Other technical installations		28,861		-		-		2,686			31,547		21,944		-		987		6.7		22,931		8,616
Subtotal assets related to natural gas transportation service		5,379,548		1,418		11,274		573,405			5,943,097		2,716,188		8,988		197,684				2,904,884		3,038,213
Assets related to natural gas upstream service		972,061		-		-		143,034			1,115,095		140,574		-		88,124		3.3 to 25		228,698		886,397
Assets related to liquids production and commercialization service		782,595		-		-		104,059			886,654		582,934		-		17,290		3.3		600,224		286,430
Lands		10,922		4		-		-			10,926		-		-		-		-		-		10,926
Buildings and constructions		206,842		-		-		22,734			229,576		106,479		-		4,597		2.0		111,076		118,500
Fittings and features in building		34,398		-		-		265			34,663		7,028		-		1,452		4.0		8,480		26,183
Machinery, equipment and tools		55,004		51,268		-		929			107,201		40,715		-		4,837		6.7 to 10		45,552		61,649
Computers and Telecommunication systems		470,349		-		-		49,345			519,694		364,652		-		31,047		6.7 to 20		395,699		123,995
Vehicles		44,900		30,577		1,972		-			73,505		28,949		1,972		6,883		20		33,860		39,645
Furniture		14,857		-		-		143			15,000		12,973		-		231		10		13,204		1,796
Capitalization of foreign exchange loss		177,272		-		-		-			177,272		113,795		-		6,275		4		120,070		57,202
Materials		482,546		312,381		5,528		(166,840	)		622,559		-		-		-		-		-		622,559
Line pack		13,872		-		-		-			13,872		1,618		-		-		-		1,618		12,254
Works in progress		804,083		1,117,603		-		(727,074	)		1,194,612		-		-		-		-		-		1,194,612
Total		9,449,249		1,513,251		18,774		-			10,943,726		4,115,905		10,960		358,420				4,463,365		6,480,361

	2016
	Cost											Depreciation
Cuenta principal	Beginning of the year		Additions		Retirements		Transfers			End of the year		Accumulated at the beginning of the year		Retirements		For the year		Rate %		Accumulated at at the end of the year		Net book value
Pipelines		3,644,917		-		-		1,794			3,646,711		1,520,415		-		86,178		2.2		1,606,593		2,040,118
Compressor plants		1,512,294		306		-		52,220			1,564,820		910,354		-		83,439		3.3 to 25		993,793		571,027
Other plants		2,868		-		-		-			2,868		554		-		97		3.3		651		2,217
Stations of regulation and/or measurement of pressure		129,228		-		-		7,060			136,288		87,972		-		5,235		4.0		93,207		43,081
Other technical installations		28,368		-		-		493			28,861		20,978		-		966		6.7		21,944		6,917
Subtotal assets related to natural gas transportation service		5,317,675		306		-		61,567			5,379,548		2,540,273		-		175,915				2,716,188		2,663,360
Assets related to natural gas upstream service		206,576		750,389		-		15,096			972,061		119,046		-		21,528		3.3 to 25		140,574		831,487
Assets related to liquids production and commercialization service		756,700		-		-		25,895			782,595		570,286		-		12,648		3.3		582,934		199,661
Lands		6,279		4,935		292		-			10,922		-		-		-		-		-		10,922
Buildings and constructions		198,796		-		-		8,046			206,842		102,436		-		4,043		2.0		106,479		100,363
Fittings and features in building		33,897		-		-		501			34,398		5,598		-		1,430		4.0		7,028		27,370
Machinery, equipment and tools		48,655		5,780		-		569			55,004		38,370		-		2,345		6.7 to 10		40,715		14,289
Computers and Telecommunication systems		419,541		660		-		50,148			470,349		308,394		-		56,258		6.7 to 20		364,652		105,697
Vehicles		33,072		12,281		453		-			44,900		24,351		389		4,987		20		28,949		15,951
Furniture		13,485		-		-		1,372			14,857		12,852		-		121		10		12,973		1,884
Capitalization of foreign exchange loss		177,272		-		-		-			177,272		106,272		-		7,523		4		113,795		63,477
Materials		356,008		209,239		6,845		(75,856	)		482,546		-		-		-		-		-		482,546
Line pack		13,872		-		-		-			13,872		1,618		-		-		-		1,618		12,254
Works in progress		467,188		424,233		-		(87,338	)		804,083		-				-		-		-		804,083
Total 2016		8,049,016		1,407,823		7,590		-			9,449,249		3,829,496		389		286,798				4,115,905		5,333,344

	2015
	Cost											Depreciation
Account	Beginning of the year		Additions		Retirements		Transfers			End of the year		Accumulated at the beginning of the year		Retirements		For the year		Rate %		Accumulated at at the end of the year		Net book value
Pipelines		3,631,240		-		-		13,677			3,644,917		1,434,424		-		85,991		2.2		1,520,415		2,124,502
Compressor plants		1,436,084		-		-		76,210			1,512,294		834,255		-		76,099	3.3 to 25			910,354		601,940
Other plants		2,868		-		-		-			2,868		456		-		98		3.3		554		2,314
Stations of regulation and/or measurement of pressure		129,228		-		-		-			129,228		82,806		-		5,166		4.0		87,972		41,256
Other technical installations		28,355		-		-		13			28,368		20,002		-		976		6.7		20,978		7,390
Subtotal assets related to natural gas transportation service		5,227,775		-		-		89,900			5,317,675		2,371,943		-		168,330				2,540,273		2,777,402
Assets related to natural gas upstream service		205,773		423		566		946			206,576		111,667		536		7,915	2.2 to 25			119,046		87,530
Assets related to liquids production and commercialization service		695,548		-		313		61,465			756,700		526,427		311		44,170		5.9		570,286		186,414
Lands		6,279		-		-		-			6,279		-		-		-		-		-		6,279
Buildings and constructions		196,204		-		-		2,592			198,796		97,700		-		4,736		2.0		102,436		96,360
Fittings and features in building		33,975		-		242		164			33,897		4,319		142		1,421		4.0		5,598		28,299
Machinery, equipment and tools		46,917		1,130		6		614			48,655		36,400		6		1,976	6.7 to 20			38,370		10,285
Computers and Telecommunication systems		389,779		-		-		29,762			419,541		286,351		-		22,043	6.7 to 20			308,394		111,147
Vehicles		31,064		2,403		395		-			33,072		21,571		395		3,175	10 and 20			24,351		8,721
Furniture		13,147		62		-		276			13,485		12,743		-		109		10		12,852		633
Capitalization of foreign exchange loss		177,272		-		-		-			177,272		98,754		-		7,518		4		106,272		71,000
Materials		286,677		161,986		8,349		(84,306	)		356,008		-		-		-		-		-		356,008
Line pack		13,872		-		-		-			13,872		1,618		-		-		-		1,618		12,254
Works in progress		327,282		241,319		-		(101,413	)		467,188		-		-		-		-		-		467,188
Total 2015		7,651,564		407,323		9,871		-			8,049,016		3,569,493		1,390		261,393				3,829,496		4,219,520