
	December 31, 2021				December 31, 2020
(Thousands of dollars)	Cost		Net		Cost	Net
Exploration and production ¹	$	20,440,568	8,098,396	2	19,583,682	8,232,191	2
Corporate and other	145,135		29,456		140,661	36,847
Property, plant and equipment	$	20,585,703	8,127,852		19,724,343	8,269,038
¹ Includes unproved mineral rights as follows:	$	615,724	131,107		649,704	530,194

In March 2021, the King’s Quay FPS was sold to ArcLight Capital Partners, LLC (ArcLight) for proceeds of $267.7 million, which reimburses the Company for previously incurred capital expenditures.

In 2019, the Company completed a divestiture of its two subsidiaries conducting Malaysian operations, Murphy Sabah Oil Co., Ltd. and Murphy Sarawak Oil Co., Ltd., in a transaction with PTT Exploration and Production Public Company Limited (PTTEP) which was effective January 1, 2019. Total cash consideration received upon closing was $2.0 billion. A gain on sale of $985.4 million was recorded as part of discontinued operations on the Consolidated Statement of Operations in 2019. Murphy was entitled to receive a $100.0 million bonus payment contingent upon certain future exploratory drilling results prior to October 2020; however, the results were not achieved.

In 2019, the Company acquired strategic deepwater Gulf of Mexico assets from LLOG Exploration Offshore L.L.C. and LLOG Bluewater Holdings, L.L.C., (LLOG). Under the terms of the transaction, Murphy paid cash consideration of $1,236.2 million and has an obligation to pay additional contingent consideration of up to $200 million in the event that certain revenue thresholds are exceeded between 2019 and 2022; and $50.0 million following first oil from certain development projects. The revenue threshold was not exceeded for 2019 or 2020; however, the threshold was met in 2021.

In 2018, the Company, through a subsidiary, acquired all of the Gulf of Mexico producing assets from Petrobras America Inc. (PAI), a subsidiary of Petrobras. Under the terms of the transaction, Murphy paid cash consideration of $780.7 million and has an obligation to pay additional contingent consideration of up to $150.0 million if certain price and production thresholds are exceeded beginning in 2019 through 2025; and $50.0 million carry for PAI development costs in the St. Malo Field if certain enhanced oil recovery projects are undertaken. The price and production thresholds were not exceeded for 2019 and 2020; however, the thresholds were met in 2021. As of December 31, 2021, Murphy had completely funded the carried interest.

During the first quarter of 2021, the Company recorded an impairment charge of $171.3 million for Terra Nova due to the status, including agreements with the partners, of operating and production plans. Subsequently, the Company acquired an additional 7.525% working interest at Terra Nova following a commercial agreement to sanction an asset life extension project.

In the fourth quarter of 2021, the Company recorded an impairment charge of $25.0 million for assets reported as Assets held for sale in the Consolidated Balance Sheet.

In 2020, declines in future oil and natural gas prices (principally driven by reduced demand in response to the COVID-19 pandemic and increased supply in the first quarter of 2020 from foreign oil producers) led to impairments in certain of the Company’s U.S. Offshore and Other Foreign properties. The Company recorded pretax noncash impairment charges of $1,206.3 million to reduce the carrying values of certain properties to their estimated fair values at the time of impairment.

The fair values were determined by internal discounted cash flow models using estimates of future production, prices, costs and discount rates believed to be consistent with those used by principal market participants in the applicable region.

The following table reflects the recognized before tax impairments for the three years ended December 31, 2021.


	December 31,
(Thousands of dollars)	2021		2020	2019
Canada	$	171,296	—	—
Other Foreign	18,000		39,709	—
Corporate	7,000		14,060	—
U.S.	—		1,152,515	—
	$	196,296	1,206,284	—

Under FASB guidance exploratory well costs should continue to be capitalized when the well has found a sufficient quantity of reserves to justify its completion as a producing well and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project.

At December 31, 2021, 2020 and 2019, the Company had total capitalized drilling costs pending the determination of proved reserves of $179.5 million, $181.6 million and $217.3 million, respectively. The following table reflects the net changes in capitalized exploratory well costs during the three-year period ended December 31, 2021.


(Thousands of dollars)	2021		2020	2019
Beginning balance at January 1	$	181,616	217,326	207,855
Additions pending the determination of proved reserves	16,725		3,999	83,712
Reclassifications to proved properties based on the determination of proved reserves	—		—	(61,096)
Capitalized exploration well costs charged to expense	(18,860)		(39,709)	(13,145)
Ending balance at December 31	$	179,481	181,616	217,326

The capitalized well costs charged to expense during 2021 and 2020 principally represent charges for asset impairments (see above). The capitalized well costs charged to expense during 2019 included the CM-1X and the CT-1X wells in Vietnam Block 11-2/11. The wells were originally drilled in 2017.

The following table provides an aging of capitalized exploratory well costs based on the date the drilling was completed for each individual well and the number of projects for which exploratory well costs has been capitalized. The projects are aged based on the last well drilled in the project.


	2021				2020				2019
(Thousands of dollars)	Amount		No. of Wells	No. of Projects	Amount		No. of Wells	No. of Projects	Amount		No. of Wells	No. of Projects
Aging of capitalized well costs:
Zero to one year	$	13,273	3	3	$	—	—	—	$	63,409	5	5
One to two years	—		—	—	54,220		5	5	—		—	—
Two to three years	53,070		5	5	—		—	—	27,396		1	—
Three years or more	113,138		6	—	127,396		6	—	126,521		5	—
	$	179,481	14	8	$	181,616	11	5	$	217,326	11	5

Of the $166.2 million of exploratory well costs capitalized more than one year at December 31, 2021, $93.1 million is in Vietnam, $45.0 million is in the U.S., $7.9 million is in Brunei, $15.3 million is in Mexico, and $4.8 million is in Canada. In all geographical areas, either further appraisal or development drilling is planned and/or development studies/plans are in various stages of completion.