Exploration Expense

3 Months Ended

Mar. 31, 2021

Extractive Industries [Abstract]

Exploration Expense

13. Exploration Expense

A summary of our exploration expense is as follows:

	Successor		Predecessor
	Period from February 10, 2021 through March 31, 2021		Period from January 1, 2021 through February 9, 2021		Three Months Ended March 31, 2020
Impairments of unproved properties	$	—	$	2	$	272
Dry hole expense	—		—		7
Geological and geophysical expense and other	1		—		3
Exploration expense	$	1	$	2	$	282

Unproved oil and natural gas properties are periodically assessed for impairment by considering future drilling and exploration plans, results of exploration activities, commodity price outlooks, planned future sales and expiration of all or a portion of the projects. The exploration expense charges during the 2020 Predecessor Period are primarily the result of non-cash impairment charges in unproved properties, primarily in our Brazos Valley, Gulf Coast, Powder River Basin and Mid-Continent operating areas.