Inventories, net (Tables)

3 Months Ended

Mar. 31, 2020

Inventory Disclosure [Abstract]

Schedule of inventories

Inventories, net, consisted of the following as of March 31, 2020 and December 31, 2019:

	(Thousands of Dollars)
	March 31, 2020		December 31, 2019
Sand, including freight	$	4,976	$	4,405
Chemicals and consumables	10,506		11,408
Materials and supplies	35,473		45,828
Total inventory, net	$	50,955	$	61,641