Our Supply and Logistics segment operations generally consist of the following merchant-related activities:
- The purchase of U.S. and Canadian crude oil at the wellhead, and the bulk purchase of crude oil at pipeline, terminal and rail facilities
- The storage of inventory during contango market conditions and the seasonal storage of NGL and natural gas
- The purchase of NGL from producers, refiners, processors and other marketers
- The resale or exchange of crude oil and NGL at various points along the distribution chain to refiners, exporters or other resellers
- The transportation of crude oil and NGL on trucks, barges, railcars, pipelines and vessels from various delivery points, market hub locations or directly to end users such as refineries, processors and fractionation facilities
Our purchase and resale of crude oil and NGL results in us generating a margin, which is reduced by the transportation, facilities and other logistical costs associated with delivering the crude oil or NGL to market as well as related operating and general and administrative expenses. A portion of our results is impacted by overall market structure and the degree of market volatility, as well as variable operating expenses. Our activities are designed to limit downside exposure, while generating upside potential associated with opportunities inherent in volatile market conditions (including opportunities to benefit from fluctuating differentials and market structure). The opportunity to realize upside potential through our supply and logistics operations has been materially reduced in recent years due to high levels of competition.
In addition to hedged working inventories associated with its merchant activities, as of December 31, 2017, our supply and logistics segment owned significant volumes of crude oil and NGL classified as long-term assets and linefill or minimum inventory requirements and employed a variety of owned or leased physical assets throughout the United States and Canada, including approximately:
14 million barrels of crude oil and NGL linefill in pipelines owned by us
730 trucks and 900 trailers
10,100 crude oil and NGL railcars
4 million barrels of crude oil and NGL linefill in pipelines owned by third parties and other long-term inventory
In connection with its operations, our Supply and Logistics segment secures transportation and facilities services from our other two segments as well as third-party service providers under month-to-month and multi-year arrangements. Intersegment fees are based on posted tariff rates, rates similar to those charged to third parties or rates that we believe approximate market rates.