For each of the following investments, we have the ability to exercise significant influence over these investments based on certain governance provisions and our participation in the significant activities and decisions that impact the management and economic performance of the investments.

Equity method investments comprise the following as of the dates indicated:


	December 31,
	2021			2020
	Ownership	Amount		Ownership	Amount
Mattox	79.0%	$	156	79.0%	$	163
Amberjack – Series A / Series B	75.0% / 50.0%	359		75.0% / 50.0%	382
Mars	71.5%	150		71.5%	152
Bengal	50.0%	85		50.0%	88
Permian Basin	50.0%	80		50.0%	83
LOCAP	41.48%	15		41.48%	12
Explorer	38.59%	68		38.59%	73
Poseidon	36.0%	—		36.0%	—
Colonial	16.125%	32		16.125%	29
Proteus	10.0%	13		10.0%	14
Endymion	10.0%	16		10.0%	17
		$	974		$	1,013


	For the Year Ended December 31,
	2021		2020		2019
Mattox (1)	$	60	$	45	$	—
Amberjack	106		102		125
Mars	83		114		126
Bengal	9		18		24
Explorer (2)	61		44		41
Colonial (2)	18		75		40
Poseidon (3)	—		—		—
Other (4)	15		19		17
	$	352	$	417	$	373

Unamortized differences in the basis of the initial investments and our interest in the separate net assets within the financial statements of the investees are amortized into net income over the remaining useful lives of the underlying assets. The amortization is included in Income from equity method investments. As of December 31, 2021 and 2020, the unamortized basis differences included in our equity method investments were $75 million and $84 million, respectively. For the years ended 2021, 2020 and 2019, the net amortization expense was $9 million, $8 million and $6 million, respectively. Included in the net amortization expense for 2021 is a write-off of approximately $2 million of unamortized basis difference as a result of an impairment taken by Colonial.

Cumulatively, distributions received from Poseidon have been in excess of our investment balance and, therefore, the equity method of accounting has been suspended for this investment and the investment amount reduced to zero. As we have no commitments to provide further financial support to Poseidon, we have recorded excess distributions of $39 million, $37 million and $33 million in Other income for the years ended December 31, 2021, 2020 and 2019, respectively. Once our cumulative share of equity earnings becomes greater than the cumulative amount of distributions received, we will resume the equity method of accounting as long as the equity method investment balance remains greater than zero.

We acquired a 79% interest in Mattox from SGOM in the April 2020 Transaction. This investment qualifies for equity method accounting, as we exercise significant influence but do not control this investment. Upon acquisition, we recorded SGOM’s historical carrying value of the equity interests transferred as a transaction between entities under common control, totaling $174 million. We recognize equity earnings for Mattox prospectively from the date of acquisition, and record the distributions from Mattox as a reduction to the equity method investment balance.

We acquired an additional 25.97% interest in Explorer and an additional 10.125% interest in Colonial in the June 2019 Acquisition. As a result, these investments now qualify for equity method accounting as we have the ability to exercise significant influence over these investments as of the acquisition date. Prior to the acquisition date, Explorer and Colonial were accounted for as Other investments without readily determinable fair values and were therefore carried at cost. Upon acquisition, we added our Parent’s historical carrying value of the equity interests transferred as a transaction between entities under common control, totaling $90 million, to the basis of our previously held interests of $60 million as this is the date these investments qualified for equity method accounting. Since the June 2019 Acquisition, we record distributions from these investments as reductions to the respective equity method investment balances for Explorer and Colonial as these amounts are

•During the fourth quarter of 2021, Colonial recorded an impairment, of which our share was approximately $44 million, that negatively impacted both our income from equity method investments and net income.

•Effective June 4, 2021, Amberjack executed an agreement to divest a small segment of the Amberjack pipeline that is no longer utilized nor deemed a material component in the operation of the pipeline. As a result of the divestment, Amberjack recorded an impairment charge of approximately $4 million during the second quarter of 2021. Our share of approximately $3 million impacted our Income from equity method investments in our consolidated statements of income. The remainder of the Amberjack pipeline continues to operate under its existing ownership structure.

•Under the lease standard, the adoption date for our equity method investments will follow the non-public business entity adoption date of January 1, 2020 for their stand-alone financial statements, with the exception of Permian Basin, which adopted on January 1, 2019. There has been no material impact on the Partnership’s consolidated financial statements as a result of the adoption of the lease standard by our equity method investees.

•On October 23, 2019, we entered into a Settlement Agreement with SPLC (the “Settlement Agreement”) with respect to the storage revenue reimbursement provision contained in the Purchase and Sale Agreement entered into in 2016 under which we acquired an additional 20% interest in Mars. Pursuant to this Purchase and Sale Agreement, SPLC had agreed to pay us up to $10 million if Mars inventory management fees do not meet certain levels for the calendar years 2017 through 2021. As a result of the Settlement Agreement, we received approximately $9 million during the fourth quarter of 2019 from SPLC that was recognized as an additional capital contribution.

We make capital contributions for our pro rata interest in Permian Basin to fund capital and other expenditures. We made capital contributions to Permian Basin of approximately $4 million and $25 million in 2021 and 2019, respectively. We did not make any capital contributions in 2020.

We assess our equity method investments for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred, if the loss is deemed to be other-than-temporary. When the loss is deemed to be other-than-temporary, the carrying value of the equity method investment is written down to fair value. We evaluated whether an impairment indicator existed as of December 31, 2021. Based on expectations of market conditions, we determined that there was no triggering event that required us to update our impairment evaluation of our equity method investments. However, if the facts and circumstances change in the near-term and indicate a loss in value that is other-than-temporary, we will re-evaluate whether the carrying amount of our equity method investments may not be recoverable.

The following tables present aggregated selected balance sheet and income statement data for our equity method investments on a 100% basis. However, during periods in which an acquisition occurs, the selected balance sheet and income statement data reflects activity from the date of the acquisition.


	For the Year Ended December 31, 2021
	Total revenues		Total operating expenses		Operating income		Net income
Statements of Income
Mattox	$	88	$	12	$	76	$	76
Amberjack	271		66		205		203
Mars	211		91		120		120
Bengal	46		29		17		17
Explorer	405		178		227		165
Colonial	1,304		1,002		302		123
Poseidon	134		37		97		93
Other (1)	213		126		87		82


	As of December 31, 2021
	Current assets		Non-current assets		Total assets		Current liabilities		Non-current liabilities		Equity (deficit)		Total liabilities and equity (deficit)
Balance Sheets
Mattox	$	11	$	195	$	206	$	—	$	9	$	197	$	206
Amberjack	53		786		839		5		134		700		839
Mars	50		245		295		26		79		190		295
Bengal	28		164		192		11		—		181		192
Explorer	85		574		659		54		508		97		659
Colonial	695		3,008		3,703		307		3,503		(107)		3,703
Poseidon	18		167		185		8		232		(55)		185
Other (1)	33		871		904		43		459		402		904


	For the Year Ended December 31, 2020
	Total revenues		Total operating expenses		Operating income		Net income
Statements of Income
Mattox (1)	$	66	$	9	$	57	$	57
Amberjack	280		78		202		201
Mars	259		97		162		163
Bengal	65		30		35		35
Explorer	329		175		154		119
Colonial	1,395		660		735		473
Poseidon	147		36		111		105
Other (2)	220		123		97		88


	As of December 31, 2020
	Current assets		Non-current assets		Total assets		Current liabilities		Non-current liabilities		Equity (deficit)		Total liabilities and equity (deficit)
Balance Sheets
Mattox (1)	$	13	$	204	$	217	$	—	$	12	$	205	$	217
Amberjack	44		836		880		10		124		746		880
Mars	47		269		316		23		103		190		316
Bengal	33		161		194		7		—		187		194
Explorer	74		537		611		49		459		103		611
Colonial	501		3,105		3,606		245		3,508		(147)		3,606
Poseidon	31		176		207		10		238		(41)		207
Other (2)	35		920		955		56		486		413		955

(1) Our interest in Mattox was acquired in the April 2020 Transaction. Mattox’s total revenues, total operating expenses and operating income (on a 100% basis) were $85 million, $12 million and $73 million, respectively.


	For the Year Ended December 31, 2019
	Total revenues		Total operating expenses		Operating income		Net income
Statements of Income
Amberjack	$	315	$	73	$	242	$	243
Mars	282		104		178		179
Bengal	77		30		47		47
Explorer (1)	258		115		143		111
Colonial (2)	829		449		380		255
Poseidon	132		35		97		87
Other (3)	190		108		82		73


	As of December 31, 2019
	Current assets		Non-current assets		Total assets		Current liabilities		Non-current liabilities		Equity (deficit)		Total liabilities and equity (deficit)
Balance Sheets
Amberjack	$	56	$	804	$	860	$	4	$	32	$	824	$	860
Mars	57		173		230		8		22		200		230
Bengal	35		157		192		6		—		186		192
Explorer (1)	93		530		623		44		442		137		623
Colonial (2)	323		2,920		3,243		519		2,873		(149)		3,243
Poseidon	30		190		220		16		246		(42)		220
Other (3)	60		917		977		73		469		435		977

(1) Our interest in Explorer was acquired on June 6, 2019. Explorer total revenues, total operating expenses and operating income (on a 100% basis) was $443 million, $196 million and $247 million, respectively.

(2) Our interest in Colonial was acquired on June 6, 2019. Colonial total revenues, total operating expenses and operating income (on a 100% basis) was $1,437 million, $735 million and $702 million, respectively.