Property, Plant and Equipment (Tables)

9 Months Ended

Sep. 30, 2015

Property, Plant And Equipment [Abstract]

Schedule of Recognized Impairments

	Three Months and Nine Months Ended
	September 30, 2015
(Thousands of dollars)		Impairment Expense	Net of Taxes
Gulf of Mexico	$	144,800	94,120
Western Canada – Heavy Oil		683,574	495,591
Malaysia		1,472,600	946,773
	$	2,300,974	1,536,484

Net Changes in Capitalized Exploratory Well Costs

(Thousands of dollars)	2015		2014
Beginning balance at January 1	$	120,455	393,030
Additions pending the determination of proved reserves		89,197	13,595
Balance at September 30	$	209,652	406,625

Aging of Capitalized Exploratory Well Costs

		September 30,
	2015				2014
(Thousands of dollars)	Amount		No. of Wells	No. of Projects	Amount		No. of Wells	No. of Projects
Aging of capitalized well costs:
Zero to one year	$	52,249	5	3	$	32,192	2	1
One to two years		32,192	2	1		36,676	2	1
Two to three years		27,842	2	–		51,898	6	–
Three years or more		97,369	4	2		285,859	22	7
	$	209,652	13	6	$	406,625	32	9