Intrastate Transportation and Storage
Three Months Ended December 31,
Natural gas transported (BBtu/d)
Cost of products sold
Unrealized gains on commodity risk management activities
Operating expenses, excluding non-cash compensation expense
Selling, general and administrative expenses, excluding non-cash compensation expense
Adjusted EBITDA related to unconsolidated affiliates
Segment Adjusted EBITDA
Transported volumes increased primarily due to higher demand for exports to Mexico, more favorable market pricing, and the addition of new pipelines to our intrastate pipeline system. These increases were partially offset by lower production volumes in the Barnett Shale region.
For the three months ended December 31, 2017 compared to the same period last year, Segment Adjusted EBITDA related to our intrastate transportation and storage segment decreased due to the net impacts of the following:
a decrease of $13 million in transportation fees due to renegotiated contracts resulting in lower billed volumes. This decrease was offset by increased margin from optimization activity recorded in natural gas sales and other; and
a decrease of $5 million in adjusted EBITDA related to unconsolidated affiliates primarily due to a decrease of $7 million due to a reserve recorded pursuant to the bankruptcy filing of a transport customer on our Louisiana intrastate system and a decrease of $2 million due to lower demand volumes related to renegotiation of a contract on our Louisiana intrastate pipeline system, offset by an increase of $4 million related to two new joint venture pipelines placed in service in 2017; offset by
an increase of $9 million in natural gas sales and other (excluding net changes in unrealized gains and losses of $12 million) primarily due to higher realized gains from pipeline optimization activity; and
an increase of $2 million in storage margin (excluding net changes in unrealized gains and losses of $4 million related to fair value inventory adjustments and unrealized gains and losses on derivatives).