|ENTERPRISE PRODUCTS PARTNERS L P filed this Form 10-K on 02/28/2018|
Revenues from midstream services increased a net $134.6 million year-to-year primarily due to the ongoing expansion of our operations. Revenues increased $144.5 million year-to-year from the assets we acquired in the EFS Midstream acquisition in July 2015. Revenues from midstream services decreased $76.0 million year-to-year due to the sale of our Offshore Business in July 2015. The remaining $66.1 million year-to-year increase in revenues from midstream services is primarily due to contractual increases in committed volumes on pipeline assets, such as ATEX and the Aegis Ethane Pipeline (“Aegis”), and the expansion of storage capacity at our terminal assets on the Gulf Coast.
Operating costs and expenses
Total operating costs and expenses for 2016 decreased $4.03 billion when compared to total operating costs and expenses for 2015. The cost of sales associated with our marketing of crude oil decreased $3.69 billion year-to-year due to lower sales volumes and prices, which accounted for a $2.53 billion decrease and a $1.16 billion decrease, respectively. The cost of sales associated with our marketing of natural gas, petrochemicals, refined products and octane additives decreased a net $416.1 million year-to-year primarily due to lower purchase prices, which accounted for a $666.1 million decrease, partially offset by a $250.0 million increase due to higher sales volumes. The cost of sales associated with our marketing of NGLs increased a net $206.5 million year-to-year primarily due to higher sales volumes, which accounted for a $754.2 million increase, partially offset by lower purchase prices, which accounted for a $547.7 million decrease.
Other operating costs and expenses decreased a net $23.8 million year-to-year primarily due to lower maintenance expenses during 2016 when compared to 2015.
Depreciation, amortization and accretion expense in operating costs and expenses for 2016 increased a net $28.5 million when compared to 2015. A $112.8 million year-to-year increase primarily due to assets we constructed and placed into service or acquired during 2016 or the later part of 2015 was partially offset by an $84.3 million decrease attributable to the sale of our Offshore Business in July 2015.
Operating costs and expenses also include $52.8 million and $162.6 million of non-cash asset impairment and related charges for the years ended December 31, 2016 and 2015, respectively. Non-cash asset impairment charges for 2016 primarily relate to the planned abandonment of plant and pipeline assets in Texas and New Mexico. Related charges for 2016 include a $7.1 million non-cash write-off for assets damaged in a fire at our Pascagoula, Mississippi natural gas processing facility in June 2016. In 2015, we recorded a $54.8 million asset impairment charge in connection with our sale of the Offshore Business. The remainder of our non-cash asset impairment charges for 2015 primarily relate to natural gas processing assets in southern Louisiana, certain marine vessels and the abandonment of certain crude oil and natural gas pipeline assets in Texas.
General and administrative costs
General and administrative costs for 2016 decreased $32.5 million when compared to 2015 primarily due to lower costs for employee compensation and professional services. General and administrative costs for 2016 include $0.7 million of non-cash asset impairment charges.
Equity in income of unconsolidated affiliates
Equity income from our unconsolidated affiliates for 2016 decreased a net $11.6 million when compared to 2015. Results for 2015 reflect $46.6 million of equity earnings attributable to the Offshore Business sold in July 2015. This year-to-year decrease was partially offset by a net $30.5 million increase in earnings from our investments in crude oil pipelines, which benefited from the settlement of a rate case by Seaway during 2016.
Operating income for 2016 increased $40.5 million when compared to 2015 due to the previously described year-to-year changes in revenues, operating costs and expenses, general and administrative costs and equity in income of unconsolidated affiliates.