Lease Operations

Based on the terms of fee-based transportation and storage services agreements with MPC as well as certain natural gas gathering, transportation and processing agreements, MPLX is considered to be the lessor under several implicit operating lease arrangements in accordance with GAAP. MPLX’s primary natural gas implicit lease operations relate to a natural gas gathering agreement in the Marcellus Shale for which it earns a fixed-fee for providing gathering services to a single producer using a dedicated gathering system. As the gathering system is expanded, the fixed-fee charged to the producer is adjusted to include the additional gathering assets in the lease. The primary term of the natural gas gathering arrangement expires in 2038 and will continue thereafter on a year-to-year basis until terminated by either party. Other significant natural gas implicit leases relate to a natural gas processing agreement in the Marcellus Shale and a natural gas processing agreement in the Southern Appalachia region for which MPLX earns minimum monthly fees for providing processing services to a single producer using a dedicated processing plant. The primary term of these natural gas processing agreements expires during 2023 and 2033. The transportation and storage services agreements with MPC are described further in Note 6. MPLX’s revenue from its implicit lease arrangements, excluding executory costs, totaled approximately $928 million in 2018, $601 million in 2017 and $586 million in 2016.

MPLX’s implicit lease arrangements related to the processing facilities contain contingent rental provisions whereby MPLX receives additional fees if the producer customer exceeds the monthly minimum processed volumes. During the years ended December 31, 2018 and 2017, MPLX received contingent lease payments of $9 million. During the year ended December 31, 2016, MPLX received $7 million of contingent lease payments.

The following is a schedule of minimum future rental revenue on the non-cancellable operating leases as of December 31, 2018:



(In millions)	Related Party		Third Party		Total
2019	$	748	$	160	$	908
2020	750		159		909
2021	627		150		777
2022	627		148		775
2023	616		142		758
2024 and thereafter	2,321		1,111		3,432
Total minimum future rentals	$	5,689	$	1,870	$	7,559

The following schedule summarizes MPLX’s investment in assets held for operating lease by major classes as of December 31, 2018 and 2017:



	December 31,
(In millions)	2018		2017
Natural gas gathering and NGL transportation pipelines and facilities	$	964	$	851
Processing, fractionation and storage facilities	1,398		573
Pipelines and related assets	266		253
Barges and towing vessels	619		491
Terminals and related assets	1,178		822
Refinery related assets	938		—
Land, building, office equipment and other	162		44
Construction-in-progress	189		85
Total	5,714		3,119
Less accumulated depreciation	2,038		1,056
Property, plant and equipment, net	$	3,676	$	2,063