Supplemental Information on Oil and Natural Gas Operations (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Extractive Industries [Abstract]

Schedule of oil and natural gas interest

Oil and natural gas interest include the following (in thousands):

	As of
	December 31,			December 31,
	2020			2019
Oil and natural gas interests:
Subject to depletion	$	319,487		$	311,954
Not subject to depletion		32,463			37,580
Gross oil and natural gas interests		351,950			349,534
Accumulated depletion and impairment		(144,445	)		(130,342	)
Oil and natural gas interests, net	$	207,505		$	219,192

Aggregate capitalized costs related to oil and natural gas production activities with applicable accumulated depreciation, depletion and amortization are as follows:

	As of December 31,
	2020			2019
	(in thousands)
Proved royalty interest	$	319,487		$	311,954
Unproved royalty interests		32,463			37,580
Accumulated amortization		(144,445	)		(130,342	)
Net royalty interests in oil and natural gas properties	$	207,505		$	219,192

Schedule of Costs Incurred in Oil and Natural Gas Property Acquisitions, Exploration and Development Activities

Costs incurred in oil and natural gas property acquisitions, exploration and development activities are as follows:

	December 31,
	2020		2019		2018
	(in thousands)
Acquisition costs:
Proved properties	$	1,066	$	4,011	$	207
Unproved properties		1,351		18,750		1,008
Total	$	2,417	$	22,761	$	1,215

Schedule of Results of Operations from Oil, Natural Gas and Natural Gas Liquids Operations

The following table sets forth the revenues and expenses related to the production and sale of oil and natural gas.  It does not include any interest costs or general and administrative costs and, therefore, is not necessarily indicative of the contribution to the net operating results of the Company’s oil, natural gas and natural gas liquids operations.  

	December 31,
	2020			2019			2018
	(in thousands)
Royalty income	$	40,081		$	68,463		$	98,655
Production and ad valorem taxes		(2,807	)		(4,262	)		(5,143	)
Marketing and transportation		(1,993	)		(2,396	)		(2,368	)
Depletion		(14,103	)		(12,737	)		(16,962	)
Income tax expense		(589	)		(3,918	)		(3,292	)
Results of operations from oil, natural gas and natural gas liquids	$	20,589		$	45,150		$	70,890

Schedule of Changes in Estimated Proved Reserves

The changes in estimated proved reserves are as follows:

	Oil			Natural Gas			Natural Gas Liquids			Total
	(MBbls)			(MMcf)			(MBbls)			(MBOE)
Proved Developed and Undeveloped Reserves:
As of December 31, 2017		18,076			58,790			4,318			32,192
Purchase of reserves in place		23			83			13			50
Extensions and discoveries		-			-			-			-
Revisions of previous estimates		421			7,514			86			1,759
Divestiture of reserves		(2,150	)		(6,155	)		(969	)		(4,145	)
Production		(1,158	)		(4,047	)		(285	)		(2,117	)
As of December 31, 2018		15,212			56,185			3,163			27,740
Purchase of reserves in place		32			70			12			56
Extensions and discoveries		215			553			71			378
Revisions of previous estimates		(1,984	)		(6,950	)		(230	)		(3,373	)
Production		(879	)		(3,588	)		(297	)		(1,774	)
As of December 31, 2019		12,596			46,270			2,719			23,027
Purchase of reserves in place		62			62			-			72
Extensions and discoveries		34			797			12			179
Revisions of previous estimates		(2,114	)		4,935			(298	)		(1,590	)
Production		(836	)		(3,528	)		(247	)		(1,671	)
As of December 31, 2020		9,742			48,536			2,186			20,017
Proved Developed Reserves
December 31, 2018		3,857			18,700			1,293			8,267
December 31, 2019		3,900			18,016			1,230			8,133
December 31, 2020		3,291			19,755			1,164			7,747
Proved Undeveloped Reserves:
December 31, 2018		11,355			37,485			1,870			19,473
December 31, 2019		8,696			28,254			1,489			14,894
December 31, 2020		6,451			28,781			1,022			12,270

Schedule of Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Natural Gas Reserves

The following table sets forth the standardized measure of discounted future net cash flows attributable to the Company’s proved oil and natural gas reserves as of December 31, 2020, 2019 and 2018:

	December 31,
	2020			2019			2018
	(in thousands)
Future cash inflows	$	476,315		$	882,076		$	1,265,153
Future production costs		(41,770	)		(70,956	)		(98,672	)
Future income tax expense		(6,431	)		(48,040	)		(87,803	)
Future net cash flows		428,114			763,080			1,078,678
10% discount to reflect timing of cash flows		(176,302	)		(304,730	)		(469,808	)
Standardized measure of discounted cash flows	$	251,812		$	458,350		$	608,870

Schedule of Average First Day of the Month Price for Oil, Natural Gas and Natural Gas Liquids

In the table below the average first-day-of–the-month price for oil, natural gas and natural gas liquids is presented, all utilized in the computation of future cash inflows:

	December 31,
	2020		2019		2018
	Unweighted Arithmetic Average
	First-Day-of-the-Month Prices
Oil (per Bbl)	$	39.57	$	55.69	$	65.56
Natural gas (per Mcf)	$	1.99	$	2.58	$	3.10
Natural gas liquids (per Bbl)	$	12.27	$	13.37	$	25.57

Schedule of Principal Changes in Standardized Measure of Discounted Future Net Cash Flows

Principal changes in the standardized measure of discounted future net cash flows attributable to the Company’s proved reserves are as follows:

	December 31,
	2020			2019			2018
	(in thousands)
Standardized measure of discounted future net cash flows at the    beginning of the period	$	458,350		$	608,870		$	595,579
Purchase of minerals in place		2,134			1,256			1,092
Sales of oil and natural gas, net of production costs		(35,281	)		(59,949	)		(91,180	)
Extensions and discoveries		1,462			9,711			-
Net changes in prices and production costs		(148,892	)		(91,386	)		165,659
Revisions of previous quantity estimates		(72,896	)		(92,479	)		41,728
Divestiture of reserves		-			-			(73,755	)
Net changes in income taxes		25,419			20,613			(49,758	)
Accretion of discount		44,279			65,863			59,558
Net changes in timing of production and other		(22,763	)		(4,149	)		(40,053	)
Standardized measure of discounted future net cash flows at the    end of the period	$	251,812		$	458,350		$	608,870